Prospectus - DWS Money Market Series, Institutional Shares · investing in high quality short-term money market instruments. Although the fund seeks to maintain a share price of $1.00

MAY 1, 2009

PROSPECTUS

INSTITUTIONAL SHARES

DWS Money Market Series

As with all mutual funds, the Securities and Exchange Commission (SEC) doesnot approve or disapprove these shares or determine whether the informationin this prospectus is truthful or complete. It is a criminal offense for anyoneto inform you otherwise.

How the Fund Works

4 The Fund’s Main Investment

Strategy

6 The Main Risks of Investing in

the Fund

10 The Fund’s Performance

History

11 How Much Investors Pay

13 Other Policies and Risks

14 Who Manages and Oversees

the Fund

16 Financial Highlights

How to Invest in the Fund

19 How to Buy Shares

20 How to Buy Shares of the

Legacy Classes

22 How to Sell Shares

23 How to Sell and Exchange

Shares of the Legacy Classes

25 Policies You Should Know

About

38 Understanding Distributions

and Taxes

41 Appendix

Contents

How the Fund WorksOn the next few pages, you’ll find information about the fund’s investment

objective, the main strategies it uses to pursue that objective and the main

risks that could affect performance.

Whether you are considering investing in the fund or are already a share-

holder, you’ll want to look this information over carefully. You may want

to keep it on hand for reference as well.

Remember that mutual funds are investments, not bank deposits. They’re

not insured or guaranteed by the FDIC or any other government agency.

Their share prices will go up and down, and you could lose money by

investing in them.

This prospectus offers one class of shares, Institutional Shares. Managed

Shares (“Institutional Shares MGD”), Prime Reserve Class S Shares

(“Institutional Shares PRS”) and Premium Class S Shares (“Institutional

Shares PS” and together with Institutional Shares MGD and Institutional

Shares PRS the “legacy classes”) were combined into Institutional Shares

as of the close of business on October 1, 2008.

Following the completion of the combination, the legacy classes will no

longer be offered separately. Because the eligibility and minimum invest-

ment requirements for each of the legacy classes differ from the Institu-

tional Shares, shareholders of each of the legacy classes may continue to

purchase shares of the fund and the investment requirements in effect for

each of the legacy classes will apply to those shareholders. Any account

privileges previously available to shareholders of the legacy classes remain

unchanged.

Institutional

Shares

Institutional

Shares MGD

Institutional

Shares PS

Institutional

Shares PRS

ticker symbol ICAXX MCAXX SPMXX SCRXX

fund number 2403 2023 2402 2309


The Fund’s Main Investment Strategy

The fund is a feeder fund that invests substantially all of itsassets in a “master portfolio,” the Cash Management Portfolio(the “Portfolio”), which will invest directly in securities andother instruments. References to the fund may refer to actionsundertaken by the Portfolio.

The fund’s goal is to seek a high level of current incomeconsistent with liquidity and the preservation of capital. Thefund, through the Portfolio, seeks to achieve its goal byinvesting in high quality short-term money market instruments.

Although the fund seeks to maintain a share price of $1.00 pershare, it is possible to lose money by investing in the fund. Allmoney market instruments, including US governmentobligations, can change in value when interest rates change oran issuer’s creditworthiness changes.

The fund maintains a dollar-weighted average maturity of 90days or less. The fund is managed in accordance with Rule 2a-7 under the Investment Company Act of 1940, as amended.

The fund follows policies designed to maintain a stable shareprice:

▪ Fund securities are denominated in US dollars and haveremaining maturities of 397 days (about 13 months) or lessat the time of purchase. The fund may also invest insecurities that have features that have the effect of reducingtheir maturities to 397 days or less at the time of purchase.

▪ The fund buys US government debt obligations, moneymarket instruments and other debt obligations that at thetime of purchase:

4 | DWS Money Market Series

- have received one of the two highest short-term ratingsfrom two nationally recognized statistical ratingorganizations (NRSROs) or one NRSRO if that NRSRO isthe only NRSRO that rates such obligations;

- are unrated, but are deemed by the Advisor to be ofcomparable quality to one of the two highest short-termratings; or

- have no short-term rating, but are rated in one of the topthree highest long-term rating categories by a NRSRO orare deemed by the Advisor to be of comparable quality.

Principal investments

The fund invests in the following investments through thePortfolio.

The fund may invest in high quality, short-term, US dollardenominated money market instruments paying a fixed,variable or floating interest rate. These include:

▪ Debt obligations issued by US and foreign banks, financialinstitutions, corporations or other entities, includingcertificates of deposit, euro-time deposits, commercialpaper (including asset-backed commercial paper), notes,funding agreements and US government securities.Securities that do not satisfy the maturity restrictions for amoney market fund may be specifically structured so thatthey are eligible investments for money market funds. Forexample, some securities have features which have theeffect of shortening the security’s maturity.

▪ US government securities that are issued or guaranteed bythe US Treasury, or by agencies or instrumentalities of theUS government.

▪ Repurchase agreements, which are agreements to buysecurities at one price, with a simultaneous agreement tosell back the securities at a future date at an agreed-uponprice.

▪ Asset-backed securities, which are generally participationsin a pool of assets whose payment is derived from thepayments generated by the underlying assets. Payments onthe asset-backed security generally consist of interest and/or principal.

DWS Money Market Series | 5

The fund will invest more than 25% of its total assets in theobligations of banks and other financial institutions that meetsthe fund’s eligibility requirements.

The fund may invest up to 10% of its total assets in othermoney market mutual funds in accordance with applicableregulations.

Securities Lending. The fund may lend its investmentsecurities in an amount up to 331⁄3% of its total assets toapproved institutional borrowers who need to borrowsecurities in order to complete certain transactions.

Working in consultation with the portfolio managers, a creditteam screens potential securities and develops a list of thosethat the fund may buy. The portfolio managers, looking forattractive yield and weighing considerations such as creditquality, economic outlooks and possible interest ratemovements, then decide which securities on this list to buy.The portfolio managers may adjust the fund’s exposure tointerest rate risk, typically seeking to take advantage ofpossible rises in interest rates and to preserve yield wheninterest rates appear likely to fall.

The Main Risks of Investing in the Fund

There are several risk factors that could reduce the yield youget from the fund, cause the fund’s performance to trail that ofother investments, or cause you to lose money.

The fund is exposed to the risk factors below even though thePortfolio, not the fund, invests directly in the individualsecurities.

Money Market Fund Risk. An investment in the fund is not

insured or guaranteed by the FDIC or any other government

agency. Although the fund seeks to preserve the value of your

investment at $1.00 per share, this share price isn’t

guaranteed and you could lose money by investing in the fund.The share price of money market funds can fall below the$1.00 share price. You should not rely on or expect the Advisorto enter into support agreements or take other actions tomaintain the fund’s $1.00 share price. The credit quality of thefund’s holdings can change rapidly in certain markets, and thedefault of a single holding could have an adverse impact on thefund’s share price. The fund’s share price can also be


negatively affected during periods of high redemptionpressures and/or illiquid markets. The actions of a few largeinvestors in the fund may have a significant adverse effect onthe share price of the fund.

Interest Rate Risk. Money market instruments, like all debtsecurities, face the risk that the securities will decline in valuebecause of changes in interest rates. Generally, investmentssubject to interest rate risk will decrease in value wheninterest rates rise and increase in value when interest ratesdecline. To reduce such price fluctuations, the fund limits thedollar-weighted average maturity of the securities held by thefund to 90 days or less. Generally, the price of short-terminvestments fluctuates less than longer-term investments.Income earned on floating or variable rate securities may varyas interest rates decrease or increase.

Credit Risk. A money market instrument’s credit qualitydepends on the issuer’s ability to pay interest on the securityand repay the debt; the lower the credit rating, the greater therisk that the security’s issuer will default, or fail to meet itspayment obligations. The credit risk of a security may alsodepend on the credit quality of any bank or financial institutionthat provides credit enhancement for it. To reduce credit risk,the fund only buys high quality securities. Also, the fund onlybuys securities with remaining maturities of 397 days(approximately 13 months) or less. This reduces the risk thatthe issuer’s creditworthiness will change, or that the issuerwill default on the principal and interest payments of theobligation. Additionally, some securities issued by USgovernment agencies or instrumentalities are supported onlyby the credit of that agency or instrumentality. There is noguarantee that the US government will provide support to suchagencies or instrumentalities and such securities may involverisk of loss of principal and interest. Securities that rely onthird party guarantors to raise their credit quality could fall inprice or go into default if the financial condition of theguarantor deteriorates.

Market Risk. Although individual securities may outperformthe market, the entire market may decline as a result of risinginterest rates, regulatory developments or deterioratingeconomic conditions.


Security Selection Risk. While the fund invests in short-termsecurities, which by their nature are relatively stableinvestments, the risk remains that the securities in which thefund invests will not perform as expected. This could cause thefund’s returns to lag behind those of similar money marketmutual funds.

Repurchase Agreement Risk. A repurchase agreementexposes the fund to the risk that the party that sells thesecurities may default on its obligation to repurchase them. Inthis circumstance, the fund can lose money because:

▪ it cannot sell the securities at the agreed-upon time andprice; or

▪ the securities lose value before they can be sold.

The fund seeks to reduce this risk by monitoring thecreditworthiness of the sellers with whom it enters intorepurchase agreements. The fund also monitors the value ofthe securities to ensure that they are at least equal to the totalamount of the repurchase obligations, including interest andaccrued interest.

Concentration Risk. Because the fund will invest more than25% of its total assets in the obligations of banks and otherfinancial institutions, it may be vulnerable to setbacks in thatindustry. Banks and other financial institutions are highlydependent on short-term interest rates and can be adverselyaffected by downturns in the US and foreign economies orchanges in banking regulations.

Prepayment Risk. A bond issuer, such as an issuer of asset-backed securities, may retain the right to pay off a highyielding bond before it comes due. In that event, the fund mayhave to reinvest the proceeds at lower interest rates. Thus,prepayment may reduce the fund’s income. It may also createa capital gains tax liability, because bond issuers usually pay apremium for the right to pay off bonds early.

Foreign Investment Risk. The fund may invest in moneymarket instruments of foreign issuers that are denominated inUS dollars. Foreign investments involve certain special risks,such as unfavorable political and legal developments, limitedfinancial information, regulatory risk and economic andfinancial instability.


Securities Lending Risk. Any loss in the market price ofsecurities loaned by the fund that occurs during the term ofthe loan would be borne by the fund and would adverselyaffect the fund’s performance. Also, there may be delays inrecovery of securities loaned or even a loss of rights in thecollateral should the borrower of the securities fail financiallywhile the loan is outstanding. However, loans will be madeonly to borrowers selected by the fund’s delegate after areview of relevant facts and circumstances, including thecreditworthiness of the borrower.


The Fund’s Performance History

While a fund’s past performance isn’t nec-essarily a sign of how it will do in the future,it can be valuable for an investor to know.

The bar chart shows how the performanceof the fund has varied from year to year,which may give some idea of risk. The tableshows how the fund’s returns over differentperiods average out. The “total return” of afund is the change in the value of an invest-ment in the fund over a given period. Aver-age annual returns are calculated by averag-ing the year-by-year returns of the fund overa given period. All figures include theeffects of the fund’s expenses and assumereinvestment of dividends and distributions.As always, past performance is no guaran-tee of future results.

The 7-day yield, which is often referred toas the “current yield,” is the income gener-ated by the fund over a seven-day period.This amount is then annualized, whichmeans that we assume the fund generatesthe same income every week for a year. Tolearn the current yield, investors may call(800) 730-1313.

Effective July 30, 2007, some of the fund’sinvestment strategies changed. The fund’spast performance would have been differentif the fund was managed using the currentstrategies.


AnnualTotal Return (%) as of 12/31 each year – Institutional Shares

2008200720062005200420032002200120001999

2.80 5.26

6.52 4.14

1.74 1.09 1.303.19

5.05 5.34

2009Total Return as of March 31: 0.22%

For the periods included in the bar chart:

Best Quarter: 1.68%, Q4 2000 Worst Quarter: 0.24%, Q3 2003

Average AnnualTotal Returns (%) as of 12/31/2008

1Year 5Years 10Years

Institutional Shares 2.80 3.53 3.63

Total returns would have been lower if operating expenses hadn’t been reduced.


How Much Investors Pay

The table below describes the fees and expenses that you may pay if you buy and hold fundshares. This information doesn’t include any fees that may be charged by your financialadvisor.

FeeTable

Institutional

Shares

Shareholder Fees, paid directly from

your investment None

Annual Operating Expenses, deducted

from fund assets

Management Fee1 0.12%

Distribution/Service (12b-1) Fee None

Other Expenses2,3 0.17

Total Annual Operating Expenses4 0.29

Less Fee Waiver/Expense

Reimbursement5,6 0.14

Net Annual Operating Expenses7 0.15

1 The management fee is paid at the Portfolio level.2 “Other Expenses” include an administrative services fee paid to the Advisor in the

amount of 0.10% from the fund and 0.03% from the Portfolio.3 Total Annual Operating Expenses reflect the actual expenses incurred during the fund’s

most recent fiscal year and include a portion of the fee paid by the fund for itsparticipation in the U.S. Treasury Department’s Temporary Guarantee Program (the“Program”), which has been extended through September 18, 2009. The cost of thefund’s participation in the Program in 2008 equaled 0.01% of average net assets. Basedon net assets as of April 15, 2009, the estimated annualized cost of the fund’sparticipation in the Program in 2009 is 0.03%. Actual expenses may be different. The feespaid by the fund for participating in the Program are excluded from the Fund’s expenselimitation.

4 Information on the annual operating expenses reflects the expenses of both the fund andthe Portfolio, in which the fund invests its assets.

5 The Portfolio’s Advisor has contractually agreed through July 29, 2010 to waive all or aportion of its management fee and reimburse or pay certain operating expenses(excluding certain expenses such as extraordinary expenses, taxes, brokerage andinterest expenses) to the extent necessary to maintain the annual expenses of thePortfolio at 0.15% of the Portfolio’s average daily net assets. (A further discussion of therelationship between the fund and the Portfolio appears in the “Who Manages andOversees the Fund — Organizational Structure” section of this prospectus.)

6 Through July 29, 2010, the Advisor has contractually agreed to waive all or a portion of itsadministrative services fee and reimburse or pay operating expenses of the fund to theextent necessary to maintain the fund’s total operating expenses at 0.15% forInstitutional Shares, excluding certain expenses such as extraordinary expenses, taxes,brokerage and interest expenses.

7 From time to time, the Advisor may voluntarily waive or reimburse certain operatingexpenses of the Portfolio and/or the fund. These voluntary waivers or reimbursementsmay be terminated at any time at the option of the Advisor.


Based on the costs above (including oneyear of capped expenses in each period),this example helps you compare theexpenses of the fund to those of othermutual funds. This example assumesoperating expenses remain the same. It

also assumes that you invested $10,000,earned 5% annual returns and reinvested alldividends and distributions and sold yourshares at the end of each period. This isonly an example; actual expenses will bedifferent.

1Year 3Years 5Years 10Years

Institutional Shares $15 $79 $149 $354


Other Policies and Risks

While the previous pages describe the main points of the fund’sstrategy and risks, there are a few other issues to know about:

▪ Although major changes tend to be infrequent, the fund’sBoard could change the fund’s investment objective withoutseeking shareholder approval.

For more information

This prospectus doesn’t tell you about every policy or risk ofinvesting in the fund.

If you want more information on the fund’s allowable securitiesand investment practices and the characteristics and risks ofeach one, you may want to request a copy of the Statement ofAdditional Information (the back cover tells you how to do this).

Keep in mind that there is no assurance that the fund willachieve its objective.

A complete list of the fund’s portfolio holdings is posted twiceeach month on www.moneyfunds.deam-us.db.com (the Website does not form a part of this prospectus). Portfolio holdingsas of the 15th day of each month are posted to the Web site onor after month-end and portfolio holdings as of each month-endare posted to the Web site on or after the 14th day of the fol-lowing month. More frequent posting of portfolio holdings infor-mation may be made from time to time onwww.moneyfunds.deam-us.db.com. The posted portfolio hold-ings information is available by fund and generally remainsaccessible at least until the date on which the fund files itsForm N-CSR or N-Q with the Securities and Exchange Commis-sion for the period that includes the date as of which the postedinformation is current. The fund also may post on the Web site,on the same or a more frequent basis, various depictions ofportfolio characteristics such as the allocation of the portfolioacross various security types, market sectors and sub-sectorsand maturities and risk characteristics of the portfolio. The fund’sStatement of Additional Information includes a description ofthe fund’s policies and procedures with respect to the disclo-sure of the fund’s portfolio holdings.

Other Policies and Risks | 13

Who Manages and Oversees the Fund

The investment advisor

Deutsche Investment Management Americas Inc. (“DIMA” orthe “Advisor”), with headquarters at 345 Park Avenue, NewYork, NY 10154, is the investment advisor for the fund and thePortfolio. Under the oversight of the Board, the Advisor makesinvestment decisions, buys and sells securities for the fund andthe Portfolio and conducts research that leads to these purchaseand sale decisions. The Advisor provides a full range of globalinvestment advisory services to institutional and retail clients.

DWS Investments is part of Deutsche Bank’s Asset Manage-ment division and, within the US, represents the retail assetmanagement activities of Deutsche Bank AG, Deutsche BankTrust Company Americas, DIMA and DWS Trust Company.

Deutsche Asset Management is a global asset managementorganization that offers a wide range of investing expertise andresources, including hundreds of portfolio managers and ana-lysts and an office network that reaches the world’s majorinvestment centers. This well-resourced global investment plat-form brings together a wide variety of experience and invest-ment insight across industries, regions, asset classes andinvesting styles.

The Advisor is an indirect, wholly owned subsidiary of DeutscheBank AG. Deutsche Bank AG is a major global banking institutionthat is engaged in a wide range of financial services, includinginvestment management, mutual funds, retail, private and com-mercial banking, investment banking and insurance.

Management Fee. The Advisor receives a management feefrom the Portfolio. Pursuant to the master/feeder structurenoted earlier in this prospectus, for the most recent fiscal year,the Portfolio paid 0.09% (reflects the effects of expense limita-tions and/or fee waivers then in effect) as a percentage of aver-age daily net assets.

A discussion regarding the basis for the Board’s approval of theinvestment management agreements for the Portfolio and thefund, respectively, is contained in the most recent shareholderreport for the annual period ended December 31 (see “Share-holder reports” on the back cover).

14 | Who Manages and Oversees the Fund

Under a separate administrative services agreement betweenthe fund and the Advisor, the fund pays the Advisor a fee forproviding most of the fund’s administrative services. In addition,the Portfolio has a separate administrative services agreementwith the Advisor pursuant to which the Portfolio pays the Advi-sor for certain administrative services.

Organizational Structure. The fund is a “feeder fund” thatinvests substantially all of its assets in a “master portfolio.” Thefund and the Portfolio have the same investment objective. ThePortfolio is advised by DIMA. The Portfolio may accept invest-ments from other feeder funds. Each feeder fund bears thePortfolio’s expenses in proportion to that feeder fund’s assets.Each feeder fund can set its own transaction minimums, fund-specific expenses and other conditions. The fund’s board mem-bers may determine to withdraw the fund’s assets from thePortfolio if they believe doing so is in the shareholders’ bestinterests. If the board members withdraw the fund’s assets,they would then consider whether the fund should hire its owninvestment advisor, invest in a different master portfolio or takeother action.

The portfolio managers

A group of investment professionals is responsible for the day-to-day management of the fund. These investment profession-als have a broad range of experience managing money marketfunds.

Who Manages and Oversees the Fund | 15

Financial Highlights

The financial highlights are designed to help you understand recent finan-cial performance. The figures in the first part of the table are for a singleshare. The total return figures represent the percentage that an investor inthe fund would have earned (or lost), assuming all dividends and distribu-tions were reinvested. This information has been audited byPricewaterhouseCoopers LLP, independent registered public accountingfirm, whose report, along with the fund’s financial statements, is includedin the fund’s annual report (see “Shareholder reports” on the back cover).

16 | Financial Highlights

DWS Money Market Series — Institutional Shares

Years Ended December 31, 2008 2007a 2007c 2006c 2005c 2004c

Selected Per Share Data

Net asset value, beginningof period $ 1.00 $ 1.00 $ 1.00 $ 1.00 $ 1.00 $ 1.00

Income from investmentoperations:

Net investment income .028 .030 .052 .039 .020 .010

Net realized and unrealizedgain (loss)*** — — — — — —

Total from investmentoperations .028 .030 .052 .039 .020 .010

Less distributions from:

Net investment income (.028) (.030) (.052) (.039) (.020) (.010)

Net asset value, end ofperiod $ 1.00 $ 1.00 $ 1.00 $ 1.00 $ 1.00 $ 1.00

Total Return (%)b 2.80 3.08** 5.37 4.02 1.98 .99

Ratios to Average Net Assets and Supplemental Data

Net assets, end of period($ millions) 19,857 21,262 17,469 8,637 12,214 8,646

Ratio of expenses beforeexpense reductions includingexpenses allocated from CashManagement Portfolio (%)d .29 .26* .24 .28 .27 .34

Ratio of expenses afterexpense reductions includingexpenses allocated from CashManagement Portfolio (%)d .14 .12* .10 .12 .13 .15

Ratio of net investmentincome (%) 2.83 5.18* 5.26 3.89 1.99 .99

a For the period from June 1, 2007 through December 31, 2007. The fund changed itsfiscal year end from May 31 to December 31.

b Total returns would have been lower had certain expenses not been reduced.c For the years ended May 31.d On July 30, 2007, DWS Money Market Series became a feeder of Cash Management

Portfolio. Expense ratios disclosed prior to December 31, 2007 are for DWS MoneyMarket Series as a stand-alone fund.

* Annualized

** Not annualized

*** Amount is less than $.0005.

Financial Highlights | 17

How to Invest in the FundThe following pages tell you how to invest in the fund and what to

expect as a shareholder. The following pages also tell you about many of

the services, choices and benefits of being a shareholder. You’ll also find

information on how to check the status of your account using the method

that’s most convenient for you.

If you’re investing directly with DWS Investments, all of this information

applies to you. If you’re investing through a “third party provider” — for

example, a workplace retirement plan, financial supermarket or financial

advisor — your provider may have its own policies or instructions and you

should follow those.

You can find out more about the topics covered here by speaking with your

financial advisor or a representative of your workplace retirement

plan or other investment provider.

How to Buy SharesThis section is a reference for eligible Institutional clients only. For shareholders of the legacyclasses, please refer to “How to Buy Shares of the Legacy Classes” on the following pages.

First investment Additional investments

$1,000,000 or more for all accounts No minimum amount

By regular, express, registered orcertified mail

▪ Fill out and sign a purchaseapplication

▪ Send it to us at the address below,along with an investment check madeout to the complete fund and classname

Mail to the address below.

▪ Send a check and a letter with yourname, account number, the full nameof the fund and class, and yourinvestment instructions to us at theaddress on the left

By wire

▪ Call (800) 730-1313 to open an accountand get an account number

▪ Please contact your financial advisorfor wire instructions on purchaseorders

▪ Complete a purchase application andsend it to us at the address below

▪ Please contact your financial advisorfor wire instructions on purchaseorders

E-Mail address —

[email protected]

To reach us: Phone number: (800) 730-1313

Web site: www.moneyfunds.deam-us.db.com

Mail: DWS Investments Service Company,

Institutional Money Funds—Client Services PO Box 219210

Kansas City, MO 64121-9210

How to Buy Shares | 19

How to Buy Shares of the Legacy ClassesBuying Institutional Shares MGD: Use the following instructions to invest directly.

Additional investments

$1,000 or more for regular accounts$100 or more for IRAs$50 or more with an Automatic Investment Plan

By mail or express mail (see below)

Send a DWS Investments investment slip or short note that includes:

▪ fund, class name and account number

▪ check payable to “DWS Investments”

By wire

▪ Call (800) 730-1313 for instructions

▪ Instruct the wiring bank to transmit the specified amount to:State Street Bank andTrust Company225 Franklin StreetBoston, MA 02110ABA#0110-0002-8DDA#9902-810-2Attn: Money Market Series—Institutional Shares MGD #2023

By phone


With an automatic investment plan

▪ To set up regular investments from a bank checking account, call(800) 730-1313

Using QuickBuy

▪ Call (800) 730-1313 to make sure QuickBuy is set up on your account; if it is, youcan request a transfer from your bank account of any amount between $50 and$250,000

On the Internet

▪ Call (800) 730-1313 to ensure you have electronic services

▪ Register at www.moneyfunds.deam-us.db.com

Phone number: 1-800-730-1313


Regular, express, registered or certified mail: Deutsche Asset Management InstitutionalMoney Funds; Client Services, 210 West 10th Street, Kansas City, MO 64105-1614

20 | How to Buy Shares of the Legacy Classes

Buying Institutional Shares PS and Institutional Shares PRS: Use the following instruc-tions to invest directly.

Additional investments

$50 or more for regular accounts and IRA accounts$50 or more with an Automatic Investment Plan

By mail or express mail (see below)

Send a DWS Investments investment slip or short note that includes:

▪ fund and class name

▪ account number

▪ check payable to “DWS Investments”

By wire


By phone


With an automatic investment plan

▪ To set up regular investments from a bank checking account, call(800) 728-3337

Using QuickBuy

▪ Call (800) 728-3337 to make sure QuickBuy is set up on your account; if it is, youcan request a transfer from your bank account of any amount between $50 and$250,000

On the Internet

▪ Call (800) 728-3337 to ensure you have electronic services

▪ Register at www.dws-investments.com

▪ Follow the instructions for buying shares with money from your bank account

Phone number: (800) 728-3337

Web site: www.dws-investments.com

Regular mail:

Additional Investments: DWS Investments, PO Box 219154, Kansas City, MO 64121-9154

Express, registered or certified mail:

DWS Investments, 210 West 10th Street, Kansas City, MO 64105-1614

How to Buy Shares of the Legacy Classes | 21

How to Sell SharesThis section is a reference for eligible Institutional clients only. For shareholders of the legacyclasses, please refer to “How to Sell and Exchange Shares of the Legacy Classes” on thefollowing pages.

By Expedited Redemption Service

If Expedited Redemption Service has been elected on the Purchase Application onfile with theTransfer Agent, redemption of shares may be requested by:

▪ telephoning Client Services at (800) 730-1313

By mail or express mail

Write a letter that includes:

▪ the fund, class, and account number from which you want to sell shares

▪ the dollar amount or number of shares you want to sell

▪ your name(s), signature(s), and address, as they appear on your account

▪ a daytime telephone number

Mail to the address below.

By phone


To reach us: Phone number: (800) 730-1313


Mail: DWS Investments Service Company,

Institutional Money Funds—Client Services PO Box 219210

Kansas City, MO 64121-9210

22 | How to Sell Shares

How to Sell and Exchange Shares of the Legacy ClassesExchanging or Selling Institutional Shares MGD: Use these instructions to exchange orsell shares in an account opened directly with DWS Investments.

Exchanging into another fund Selling shares

To open a new account: same minimumas for a first investmentFor exchanges between existingaccounts: $1,000 or more

Some transactions, including most forover $100,000, can only be ordered inwriting with a signature guarantee;please see “Signature Guarantee”

By phone or wire

▪ Call (800) 730-1313 for instructions ▪ Call (800) 730-1313 for instructions


Your instructions should include:

▪ the fund, class and account numberyou’re exchanging out of

▪ the dollar amount or number of sharesyou want to exchange

▪ the name and class of the fund youwant to exchange into

▪ your name(s), signature(s) andaddress, as they appear on youraccount



▪ the fund, class and account numberyou’re redeeming from

▪ the dollar amount or number of sharesyou want to sell



With an automatic exchange plan With an automatic withdrawal plan

▪ To set up regular exchanges from afund account, call (800) 730-1313

▪ To set up regular withdrawals from afund account, call (800) 730-1313

Using QuickSell

Not available▪ Call (800) 730-1313 to make sure

QuickSell is set up on your account; ifit is, you can request a transfer to yourbank account of any amount between$50 and $250,000

Using Checkwriting

Not available▪ Call (800) 730-1313 for instructions

Phone number: 1-800-730-1313


Regular, express, registered or certified mail: Deutsche Asset Management InstitutionalMoney Funds; Client Services, 210 West 10th Street, Kansas City, MO 64105-1614

How to Sell and Exchange Shares of the Legacy Classes | 23

Exchanging or Selling Institutional Shares PS and Institutional Shares PRS: Use theseinstructions to exchange or sell shares in an account opened directly with DWS Investments.

Exchanging into another fund Selling shares

To open a new account: same minimumas for a first investmentFor exchanges between existingaccounts: $50 or more

Some transactions, including most forover $100,000, can only be ordered inwriting with a signature guarantee;please see “Signature Guarantee”

By phone or wire


Using the Automated Information Line




▪ the fund, class and account numberyou’re exchanging out of

▪ the dollar amount or number of sharesyou want to exchange

▪ the name and class of the fund youwant to exchange into




▪ the fund, class and account numberyou’re redeeming from

▪ the dollar amount or number of sharesyou want to sell



With an automatic exchange plan With an automatic withdrawal plan

▪ To set up regular exchanges from afund account, call (800) 728-3337

▪ To set up regular withdrawals from afund account, call (800) 728-3337

Using QuickSell

Not available▪ Call (800) 728-3337 to make sure

QuickSell is set up on your account; ifit is, you can request a transfer to yourbank account of any amount between$50 and $250,000

Using Checkwriting

Not available▪ Write a check on your account. See

“Checkwriting” under “Policies abouttransactions” for checkwritingminimums

On the Internet



Phone number: (800) 728-3337

Web site: www.dws-investments.com

Regular mail:

Additional Investments: DWS Investments, PO Box 219154, Kansas City, MO 64121-9154

Express, registered or certified mail:

DWS Investments, 210 West 10th Street, Kansas City, MO 64105-1614

24 | How to Sell and Exchange Shares of the Legacy Classes

Policies You Should Know About

Along with the information on the previous pages, the policiesbelow may affect you as a shareholder. Some of this informa-tion, such as the section on distributions and taxes, applies toall investors, including those investing through a financialadvisor.

If you are investing through a financial advisor or through aretirement plan, check the materials you received from themabout how to buy and sell shares because particular financialadvisors or other intermediaries may adopt policies, proceduresor limitations that are separate from those described by thefund. Please note that a financial advisor may charge fees sepa-rate from those charged by the fund and may be compensatedby the fund.

Keep in mind that the information in this prospectus applies onlyto the shares offered herein. Other share classes are describedin separate prospectuses and have different fees, requirementsand services.

In order to reduce the amount of mail you receive and to helpreduce expenses, we generally send a single copy of any share-holder report and prospectus to each household. If you do notwant the mailing of these documents to be combined withthose for other members of your household, please contactyour financial advisor or call (800) 730-1313.

Financial intermediary support payments

The Advisor, DWS Investments Distributors, Inc. (the “Distribu-tor”) and/or their affiliates may pay additional compensation, outof their own assets and not as an additional charge to the fund,to selected affiliated and unaffiliated brokers, dealers, participat-ing insurance companies or other financial intermediaries(“financial advisors”) in connection with the sale and/or distribu-tion of fund shares or the retention and/or servicing of fundinvestors and fund shares (“revenue sharing”). Such revenuesharing payments are in addition to any distribution or servicefees payable under any Rule 12b-1 or service plan of the fund,any record keeping/sub-transfer agency/networking fees pay-able by the fund (generally through the Distributor or an affiliate)and/or the Distributor to certain financial advisors for performingsuch services and any sales charge, commissions, non-cashcompensation arrangements expressly permitted under appli-cable rules of the Financial Industry Regulatory Authority or

Policies You Should Know About | 25

other concessions described in the fee table or elsewhere inthis prospectus or the Statement of Additional Information aspayable to all financial advisors. For example, the Advisor, theDistributor and/or their affiliates may compensate financial advi-sors for providing the fund with “shelf space” or access to athird party platform or fund offering list or other marketing pro-grams, including, without limitation, inclusion of the fund onpreferred or recommended sales lists, mutual fund “supermar-ket” platforms and other formal sales programs; granting theDistributor access to the financial advisor’s sales force; grantingthe Distributor access to the financial advisor’s conferences andmeetings; assistance in training and educating the financial advi-sor’s personnel; and obtaining other forms of marketing sup-port.

The level of revenue sharing payments made to financial advi-sors may be a fixed fee or based upon one or more of the fol-lowing factors: gross sales, current assets and/or number ofaccounts of the fund attributable to the financial advisor, theparticular fund or fund type or other measures as agreed to bythe Advisor, the Distributor and/or their affiliates and the finan-cial advisors or any combination thereof. The amount of theserevenue sharing payments is determined at the discretion of theAdvisor, the Distributor and/or their affiliates from time to time,may be substantial, and may be different for different financialadvisors based on, for example, the nature of the services pro-vided by the financial advisor.

The Advisor, the Distributor and/or their affiliates currently makerevenue sharing payments from their own assets in connectionwith the sale and/or distribution of DWS fund shares or theretention and/or servicing of investors and DWS fund shares tofinancial advisors in amounts that generally range from .01% upto .50% of assets of the fund serviced and maintained by thefinancial advisor, .05% to .25% of sales of the fund attributableto the financial advisor, a flat fee of $13,350 up to $500,000, orany combination thereof. These amounts are subject to changeat the discretion of the Advisor, the Distributor and/or their affili-ates. Receipt of, or the prospect of receiving, this additionalcompensation may influence your financial advisor’s recommen-dation of the fund or of any particular share class of the fund.You should review your financial advisor’s compensation disclo-sure and/or talk to your financial advisor to obtain more informa-tion on how this compensation may have influenced your finan-cial advisor’s recommendation of the fund. Additional

26 | Policies You Should Know About

information regarding these revenue sharing payments isincluded in the fund’s Statement of Additional Information,which is available to you on request at no charge (see the backcover of this prospectus for more information on how to requesta copy of the Statement of Additional Information).

The Advisor, the Distributor and/or their affiliates may also makesuch revenue sharing payments to financial advisors under theterms discussed above in connection with the distribution ofboth DWS funds and non-DWS funds by financial advisors toretirement plans that obtain record keeping services from ADP,Inc. on the DWS Investments branded retirement plan platform(the “Platform”) with the level of revenue sharing paymentsbeing based upon sales of both the DWS funds and the non-DWS funds by the financial advisor on the Platform or currentassets of both the DWS funds and the non-DWS funds servicedand maintained by the financial advisor on the Platform.

It is likely that broker-dealers that execute portfolio transactionsfor the fund will include firms that also sell shares of the DWSfunds to their customers. However, the Advisor will not con-sider sales of DWS fund shares as a factor in the selection ofbroker-dealers to execute portfolio transactions for the DWSfunds. Accordingly, the Advisor has implemented policies andprocedures reasonably designed to prevent its traders from con-sidering sales of DWS fund shares as a factor in the selection ofbroker-dealers to execute portfolio transactions for the fund. Inaddition, the Advisor, the Distributor and/or their affiliates willnot use fund brokerage to pay for their obligation to provideadditional compensation to financial advisors as describedabove.

Policies about transactions

To help the government fight the funding of terrorism andmoney laundering activities, federal law requires all financialinstitutions to obtain, verify and record information that identi-fies each person who opens an account. What this means toyou: When you open an account, we will ask for your name,address, date of birth and other information that will allow us toidentify you. Some or all of this information will be used toverify the identity of all persons opening an account.


We might request additional information about you (which mayinclude certain documents, such as articles of incorporation forcompanies) to help us verify your identity and, in some cases,the information and/or documents may be required to conductthe verification. The information and documents will be usedsolely to verify your identity.

We will attempt to collect any missing required and requestedinformation by contacting you or your financial advisor. If we areunable to obtain this information within the time frames estab-lished by the fund, then we may reject your application andorder.

The fund will not invest your purchase until all required andrequested identification information has been provided and yourapplication has been submitted in “good order.” After wereceive all the information, your application is deemed to be ingood order and we accept your purchase, you will receive thenet asset value per share next calculated.

If we are unable to verify your identity within time frames estab-lished by the fund, after a reasonable effort to do so, you willreceive written notification.

With certain limited exceptions, only US residents may invest inthe fund.

Because orders placed through a financial advisor must be for-warded to the transfer agent before they can be processed,you’ll need to allow extra time. Your financial advisor should beable to tell you approximately when your order will be pro-cessed. It is the responsibility of your financial advisor to for-ward your order to the transfer agent in a timely manner.

Transaction Processing. Except as provided below, purchase,redemption and exchange orders must be received in goodorder by 4:00 p.m. Eastern time (or prior to the close of thefund, if the New York Stock Exchange closes early on such date)on a business day on which the fund is open in order to beeffective on that day; otherwise such orders will be effective onthe next business day. However, on a normal business day thatthe fund calculates its share price at 5:00 p.m. Eastern time asprovided below, purchase orders with payment sent by wire andredemption orders with proceeds to be sent by wire, ACH or by


check that are communicated by telephone (but not by theAutomated Information Line, as applicable) and are received ingood order by 5:00 p.m. Eastern time on a business day will beeffective on that business day.

Orders for the purchase of shares by wire transfer will normallybe effective at the share price next computed after receipt ofthe wire transfer of the amount to be invested. If a wire transferpurchase order is received in good order before 5:00 p.m. East-ern time, it will normally receive the dividend for that day.

Shareholders known to the fund may notify Institutional Invest-ment Services in advance of their wire transfer purchase by call-ing Institutional Investment Services prior to the 5:00 p.m. East-ern time cut-off time and provide the amount of the order. Theinvestor will receive a confirmation number for the trade. If thefund receives the wire transfer before the close of the FederalFunds wire system, the trade will be entitled to that day’s divi-dend. If the fund does not receive the wire transfer by the closeof the Federal Funds wire system, the trade may not receive thedividend for that day and, depending upon the circumstances,the trade may receive the dividend for the following businessday or may be canceled or rejected and, in any case, the inves-tor may be charged for any losses or fees that result, which maybe paid by deductions from their account or otherwise. Thefund’s Distributor may refuse to allow any investor to trade withthe fund in this manner and may require that the wire transferof purchase proceeds be received before the trade is consid-ered in good order.

Investments by check will be effective on the business day fol-lowing receipt and will earn dividends the following businessday. If you pay for shares by check and the check fails to clear,we have the right to cancel your order, hold you liable or chargeyou or your account for any losses or fees the fund or its agentshave incurred.

Orders processed through dealers or other financial servicesfirms via Fund/SERV will be effected at the share price calcu-lated on the trade day (normally the date the order is received).Purchases processed via Fund/SERV will begin earning divi-dends on the day the fund receives the payment (typically thenext business day). For redemptions processed via Fund/SERV,you generally will receive dividends accrued up to, but notincluding, the business day that payment for your shares ismade.


When selling shares, shareholders generally receive dividendsup to, but not including, the business day following the day onwhich the shares were sold. To sell shares, you must statewhether you would like to receive the proceeds by wire orcheck.

In order to receive proceeds by wire, contact InstitutionalInvestment Services before 5:00 p.m. Eastern time. After youinform Institutional Investment Services of the amount of yourredemption, you will receive a trade confirmation number. If thefund receives a sell request before 5:00 p.m. Eastern time andthe request calls for proceeds to be sent out by wire, the pro-ceeds will normally be wired on the same day. However, theshares sold will not earn that day’s dividend.

As noted elsewhere in the prospectus, proceeds of a redemp-tion may be delayed. The ability to receive “same day” wireredemption proceeds can be affected by a variety of circum-stances including the time that the request is made, the level ofredemption requests and purchase orders and general marketconditions. A request for a same day wire that is received earlierin the day will be given priority over a request received later inthe day in the event that it is necessary to limit the amount ofsame day wire redemptions.

Your initial investment must be for at least $1,000,000. Thereare no minimum subsequent investment requirements.

The minimum initial investment is waived for:

▪ Shareholders with existing accounts prior to August 13, 2004who met the previous minimum investment eligibility require-ment.

▪ Investment advisory affiliates of Deutsche Bank Securities,Inc., DWS funds or Deutsche funds purchasing shares for theaccounts of their investment advisory clients.

▪ Employee benefit plans with assets of at least $50 million.

▪ Clients of the private banking division of Deutsche Bank AG.

▪ Institutional clients and qualified purchasers that are clientsof a division of Deutsche Bank AG.

▪ A current or former director or trustee of the Deutsche orDWS funds.


▪ An employee, the employee’s spouse or life partner and chil-dren or stepchildren age 21 or younger of Deutsche Bank orits affiliates or a subadvisor to any fund in the DWS family offunds or a broker-dealer authorized to sell shares of thefunds.

▪ Registered investment advisors who trade through platformsapproved by the Advisor and whose client assets in theaggregate meet or, in the Advisor’s judgment, will meetwithin a reasonable period of time, the $1,000,000 minimuminvestment.

▪ Employee benefit plan platforms approved by the Advisorthat invest in the fund through an omnibus account, and thatmeet or, in the Advisor’s judgment, will meet within a rea-sonable period of time, the $1,000,000 minimum investment.

The fund reserves the right to modify the above eligibilityrequirements and investment minimum at any time. In addition,the fund, in its discretion, may waive the minimum initial invest-ment for specific employee benefit plans (or family of plans)whose aggregate investment in Institutional Class shares of thefund equals or exceeds the minimum initial investment amountbut where a particular account or program may not on its ownmeet such minimum amount.

Sub-Minimum Balances. The fund may close your account andsend you the proceeds if your balance falls below $1,000,000($100,000 for Institutional Shares MGD, $20,000 for InstitutionalShares PS and $7,500 for Institutional Shares PRS); we will giveyou 60 days’ notice so you can either increase your balance orclose your account (these policies don’t apply to most retire-ment accounts).

For more information on how to buy or sell shares by mail, referto “Policies about transactions — Transaction Processing”below.


WIRE:

Buying: You may buy shares by wire only if your account isauthorized to do so. Instruct your bank to send payment by wireusing the wire instructions below.

Bank Name: State Street Bank Boston

Routing No: 011000028

Attn: DWS Investments

DDA No: 99028102

FBO: (Account name) (Account number)

Credit: (Fund name, Fund number and, if applicable, classname) (Refer to the start of “The Fund’s MainInvestment Strategy” above for the fund number.)

Refer to your account statement for the account name andnumber. Wire transfers normally take two or more hours tocomplete. Wire transfers may be restricted on holidays and atcertain other times.

Selling: You may sell shares by wire only if your account isauthorized to do so. You will be paid for redeemed shares bywire transfer of funds to your financial advisor or bank uponreceipt of a duly authorized redemption request as promptly asfeasible. For your protection, you may not change thedestination bank account over the phone.

For more information on how to buy or sell shares by wire, referto “Policies about transactions — Transaction Processing”below.

The automated information line is available 24 hours a dayby calling (800) 728-3337 for Institutional Shares PRS andInstitutional Shares PS. You can use our automated phoneservices to get information on DWS funds generally and onaccounts held directly at DWS Investments. Accountinformation for Institutional Shares and Institutional SharesMGD can be accessed by calling (800) 730-1313.

QuickBuy and QuickSell let you set up a link between a DWSfund account and a bank account. Once this link is in place, youcan move money between the two with a phone call. You’llneed to make sure your bank has Automated Clearing House(ACH) services. Transactions take two to three days to be


completed and there is a $50 minimum and a $250,000maximum. To set up QuickBuy or QuickSell on a new account,see the account application; to add it to an existing account,please contact us.

Telephone and electronic transactions. Generally, you areautomatically entitled to telephone check redemption andexchange privileges, but you may elect not to have them whenyou open your account or by contacting Institutional InvestmentServices at (800) 730-1313 at a later date.

Since many transactions may be initiated by telephone orelectronically, it’s important to understand that as long as wetake reasonable steps to ensure that an order to purchase orredeem shares is genuine, such as recording calls or requestingpersonal security information, we are not responsible for anylosses that may occur as a result. For transactions conductedover the Internet, we recommend the use of a secure Internetbrowser. In addition, you should verify the accuracy of yourconfirmation statements immediately after you receive them.

Checkwriting enables you to sell shares of the fund by writinga check. Your investment keeps earning dividends until yourcheck clears. Please note that we will not accept checks for lessthan $1,000 ($100 for Institutional Shares PS and InstitutionalShares PRS). Please note that you should not write checks formore than $5,000,000. Note as well that we can’t honor anycheck larger than your balance at the time the check ispresented to us. It is not a good idea to close out an accountusing a check because the account balance could changebetween the time you write the check and the time it isprocessed. Please keep in mind that if you make a purchase bycheck and that check has not yet cleared, those funds will notbe available for immediate redemption.

Regular investments and withdrawals enable you to set up alink between the fund account and a bank account. Once thislink is in place, you can move money between the two with aphone call. You’ll need to make sure your bank has AutomatedClearing House (ACH) services. Transactions take two to threedays to be completed.

The fund accepts Automated Clearing House (“ACH”) debitentries for accounts that have elected the checkwritingredemption privilege. Upon receipt of an ACH debit entryreferencing your account number you authorize us to redeemshares in your account to pay the entry to the third party


originating the debit. Your fund account statement will show allACH debit entries in your account. In case of errors orquestions about your transactions or pre-authorizedtransfers please contact your financial advisor as soon aspossible if you believe your statement reflects an impropercharge or if you need more information about an ACH debitentry transaction. Your financial advisor must contact theShareholder Service Agent within sixty (60) days of the fundsending you the first fund account statement on which animproper charge appears.

Expedited Redemptions. Expedited Redemption Serviceallows you to have proceeds from your sales of fund shareswired directly to a bank account. To use this service, you’ll needto designate the bank account in advance. Follow theinstructions on your application.

When you ask us to send or receive a wire, please note thatwhile we don’t charge a fee to send or receive wires, it’spossible that your bank may do so. Wire transactions aregenerally completed within 24 hours. The fund can only sendwires of $1,000 or more and accept wires of $50 or more.

The fund does not issue share certificates. However, if youcurrently have shares in certificated form, you must include theshare certificates properly endorsed or accompanied by a dulyexecuted stock power when exchanging or redeeming shares.You may not exchange or redeem shares in certificate form bytelephone or via the Internet.

The fund accepts payment for shares only in US dollars by acheck drawn on a US bank, a bank or Federal Funds wiretransfer or an electronic bank transfer. The fund does not acceptthird party checks. A third party check is a check made payableto one or more parties and offered as payment to one or moreother parties (e.g., a check made payable to you that you offeras payment to someone else). Checks should normally bepayable to DWS Investments and drawn by you or a financialinstitution on your behalf with your name or account numberincluded with the check.

Signature Guarantee. When you want to sell more than$100,000 worth of shares or send proceeds to a third party or toa new address, you’ll usually need to place your order in writingand include a signature guarantee. However, if you want money


transferred electronically a bank account that is already on filewith us, you don’t need a signature guarantee. Also, generallyyou don’t need a signature guarantee for an exchange, althoughwe may require one in certain other circumstances.

A signature guarantee is simply a certification of yoursignature — a valuable safeguard against fraud. You can get asignature guarantee from an eligible guarantor institution,including commercial banks, savings and loans, trustcompanies, credit unions, member firms of a national stockexchange or any member or participant of an approved signatureguarantor program. We recommend stamps from members of amedallion signature guarantee program. Note that you can’t geta signature guarantee from a notary public and we must beprovided the original guarantee.

Selling shares of trust accounts and business ororganization accounts may require additional documentation.Please call (800) 730-1313 or contact your financial advisor formore information.

Money from shares you sell is sent out within one businessday of the business day that your redemption order is effectiveexcept as discussed below. It could be longer when you areselling shares you bought recently by check or ACH (the fundswill be placed under a 10 calendar day hold to ensure goodfunds) or when unusual circumstances prompt the SEC to allowfurther delays. Certain expedited redemption processes (e.g.,redemption proceeds by wire) may also be delayed orunavailable when you are selling shares recently purchased bycheck or ACH or in the event of the closing of the FederalReserve wire payment system. The fund reserves the right tosuspend or postpone redemptions as permitted pursuant toSection 22(e) of the Investment Company Act of 1940. Thosecircumstances are when 1) the New York Stock Exchange isclosed other than customary weekend or holiday closings; 2)trading on the New York Stock Exchange is restricted; 3) anemergency exists which makes the disposal of securitiesowned by the fund or the fair determination of the value of thefund’s net assets not reasonably practicable; or 4) the SEC, byorder, permits the suspension of the right of redemption.Redemption payments by wire may also be delayed in the eventof a non-routine closure of the Federal Reserve wire paymentsystem. For additional rights reserved by the fund, please see“Other rights we reserve.”


You may obtain additional information about other ways to sellyour shares by contacting your financial advisor.

Short-TermTrading. Since money market funds hold short-terminstruments and are intended to provide liquidity toshareholders, the Advisor does not monitor or limit short-termor excessive trading activity in the fund and, accordingly, theBoard of the fund has not approved any policies and proceduresdesigned to limit this activity. However, the fund reserves theright to and may reject or cancel a purchase or exchange orderinto the fund for any reason, including if, in the opinion of theAdvisor, there appears to be a pattern of short-term orexcessive trading by an investor in another DWS fund.

How the fund calculates share price

To calculate net asset value, or NAV, each share class uses thefollowing equation:

TOTAL ASSETS –TOTAL LIABILITIES

TOTAL NUMBER OF SHARES OUTSTANDING= NAV

The price at which you buy and sell shares is based on the NAVper share next calculated after the order is received andaccepted by the transfer agent.

In valuing securities, we typically use amortized cost (themethod used by most money market funds) to account for anypremiums or discounts above or below the face value of anysecurities the fund buys, and round the per share NAV to thenearest whole cent.

The fund is open for business each day the New York StockExchange (the “Exchange”) is open. Normally, the fundcalculates its share price once every business day at 5:00 p.m.Eastern time. The close of regular trading on the Exchange istypically 4:00 p.m. Eastern time, but sometimes earlier, as inthe case of scheduled half-day trading or unscheduledsuspensions of trading. In the event of scheduled partial daytrading or unscheduled suspensions of trading on the Exchange,the calculation of share price shall be as of the close of tradingon the Exchange. In such instances, the latest time for receiptof wire purchase transactions entitled to receive same day


dividend treatment and for receipt of redemption orders forsame day wire transfer of proceeds will be the earlier of (a) 5:00p.m. Eastern time or (b) the early closing time of the Exchange.The fund seeks to maintain a stable $1.00 share price.

The fund may, but is not required to, accept certain types ofpurchase and redemption orders (not including exchanges) ondays that the Exchange is closed, or beyond an Exchange earlyclosing time (referred to as a ”Limited Trading Period”) if: (a) theFederal Reserve system is open, (b) the primary trading marketsfor the fund’s portfolio instruments are open and (c) the Advisorbelieves there will be adequate liquidity in the short-termmarkets. During any such Limited Trading Period, the fund willonly accept purchase orders by wire with advance telephonenotification and telephone redemption orders with proceeds tobe sent by wire, ACH or check and will not accept orders by anyother means. (Automated Telephone Line orders are notpermitted.) If redemption proceeds are requested by ACH orcheck, the transmission of the ACH payment or the mailing ofthe check, as the case may be, will be delayed by at least onebusiness day in comparison to normal trading periods. Orderssubmitted by other means will be processed on the next daythat the Exchange is open. The calculation of share price will beas set forth in the prospectus for normal trading days. Ordersmust be submitted by the cut-off times for receipt of wirepurchases entitled to that day’s dividend and for receipt oftelephone redemption orders for same day wire transfer, whichwill be the earlier of: (a) the times set forth in the prospectus fornormal trading days or (b) such earlier times that the funddetermines based on the criteria described above. If redemptionproceeds are requested by ACH or check, orders must bereceived prior to the calculation of share price. Please call (877)237-1131 or visit our Web site at www.moneyfunds.deam-us.db.com for additional information about whether the fundwill be open for business on a particular day. Informationconcerning the intention of the fund to be open for a LimitedTrading Period will be available at least one business day prior tothe applicable day that the Exchange is closed or is closing earlyin the case of scheduled closings and as soon as practical in thecase of unscheduled closings.

Other rights we reserve

You should be aware that we may do any of the following:

▪ withdraw or suspend the offering of shares at any time


▪ withhold a portion of your distributions and redemptionproceeds if we have been notified by the IRS that you aresubject to backup withholding or if you fail to provide us withthe correct taxpayer ID number and certain certifications,including certification that you are not subject to backupwithholding

▪ reject a new account application if you don’t provide anyrequired or requested identifying information, or for any otherreason

▪ refuse, cancel, limit or rescind any purchase or exchangeorder, without prior notice; freeze any account (meaning youwill not be able to purchase fund shares in your account);suspend account services; and/or involuntarily redeem youraccount if we think that the account is being used forfraudulent or illegal purposes; one or more of these actionswill be taken when, at our sole discretion, they are deemedto be in the fund’s best interests or when the fund isrequested or compelled to do so by governmental authorityor by applicable law

▪ close and liquidate your account if we are unable to verifyyour identity, or for other reasons; if we decide to close youraccount, your fund shares will be redeemed at the net assetvalue per share next calculated after we determine to closeyour account (less applicable redemption fee, if any); you mayrecognize a gain or loss on the redemption of your fundshares and you may incur a tax liability

▪ change, add or withdraw various services, fees and accountpolicies (for example, we may adjust the fund’s investment

minimums at any time)

Understanding Distributions and

Taxes

The fund intends to distribute to its shareholdersvirtually all of its net earnings. The fund can earnmoney in two ways: by receiving interest, dividendsor other income from securities it holds and byselling securities for more than it paid for them.(The fund’s earnings are separate from any gains orlosses stemming from your own purchase and saleof shares.) The fund may not always pay a dividendor distribution for a given period.

38 | Understanding Distributions and Taxes

Because each

shareholder’s tax

situation is

unique, ask your

tax professional

about the tax

consequences of

your invest-

ments, including

any state and

local tax

consequences.

The fund’s income dividends are declared daily and paidmonthly to shareholders. The fund may take into accountcapital gains and losses (other than net long-term capital gains)in its daily dividend declarations. The fund may make additionaldistributions for tax purposes if necessary.

Dividends or distributions declared and payable to shareholdersof record in the last quarter of a given calendar year are treatedfor federal income tax purposes as if they were received onDecember 31 of that year, provided such dividends ordistributions are paid by the end of the following January.

For federal income tax purposes, income and capital gainsdistributions are generally taxable to shareholders. However,dividends and distributions received by retirement plansqualifying for tax exemption under federal income tax lawsgenerally will not be taxable.

You can choose how to receive your dividends anddistributions. You can have them all automatically reinvested infund shares (at NAV), sent to you by check or wired to your bankaccount of record. Tell us your preference on your application. Ifyou don’t indicate a preference, your dividends and distributionswill all be reinvested. Under the terms of employer-sponsoredqualified plans, and retirement plans, reinvestment is the onlyoption.

Distributions are treated the same for federal income taxpurposes whether you receive them in cash or reinvest them inadditional shares. For federal income tax purposes, an exchangeis treated the same as a sale.

Because the fund seeks to maintain a stable share price, youare unlikely to have capital gains or losses when you sell fundshares.

For federal income tax purposes, distributions of net investmentincome are taxable as ordinary income. The fund does notexpect to make distributions that are eligible for taxation aslong-term capital gains or as qualified dividend income.

The use of a master/feeder structure could affect the amount,timing and character of distributions, and therefore, mayincrease the amount of taxes payable to shareholders.

Understanding Distributions and Taxes | 39

Your fund will send you detailed federal income tax informationevery January. These statements tell you the amount and thefederal income tax classification of any dividends ordistributions you received. They also have certain details on yourpurchases and sales of shares.

If the fund’s distributions exceed its current and accumulatedearnings and profits, the excess will be treated for federalincome tax purposes as a return of capital to the extent of yourbasis in your shares and thereafter as a gain from the sale orexchange of your shares. A return of capital distribution reducesthe basis of your shares. As a result, even though the fundseeks to maintain a stable share price, you may recognize acapital gain when you sell your shares if you have received areturn of capital distribution.

The above discussion summarizes certain federal income taxconsequences for shareholders who are US persons. If you area non-US person, please consult your own tax advisor withrespect to the US tax consequences to you of an investment inthe fund. For more information, see “Taxes” in the Statementof Additional Information.

40 | Understanding Distributions and Taxes

Appendix

Hypothetical Expense Summary

Using the annual fund operating expense ratios presented in thefee tables in the fund prospectus, the Hypothetical ExpenseSummary shows the estimated fees and expenses, in actualdollars, that would be charged on a hypothetical investment of$10,000 in the fund held for the next 10 years and the impact ofsuch fees and expenses on fund returns for each year andcumulatively, assuming a 5% return for each year. The historicalrate of return for the fund may be higher or lower than 5% and,for money funds, is typically less than 5%. The tables alsoassume that all dividends and distributions are reinvested. Theannual fund expense ratios shown are net of any contractual feewaivers or expense reimbursements, if any, for the period of thecontractual commitment. Also, please note that if you areinvesting through a third party provider, that provider may havefees and expenses separate from those of the fund that are notreflected here. Mutual fund fees and expenses fluctuate overtime and actual expenses may be higher or lower than thoseshown.

The Hypothetical Expense Summary should not be used or con-strued as an offer to sell, a solicitation of an offer to buy or arecommendation or endorsement of any specific mutual fund.You should carefully review the fund’s prospectus to considerthe investment objectives, risks, expenses and charges of thefund prior to investing.

Appendix | 41

DWS Money Market Series – Institutional Shares

MaximumSales Charge:

0.00%

Initial HypotheticalInvestment:

$10,000

Assumed Rateof Return:

5%

Year

CumulativeReturn Before

Fees andExpenses

AnnualFund

ExpenseRatios

CumulativeReturn After

Fees andExpenses

HypotheticalYear-End

Balance AfterFees andExpenses

Annual Feesand

Expenses

1 5.00% 0.15% 4.85% $10,485.00 $ 15.36

2 10.25% 0.29% 9.79% $10,978.84 $ 31.12

3 15.76% 0.29% 14.96% $11,495.95 $ 32.59

4 21.55% 0.29% 20.37% $12,037.41 $ 34.12

5 27.63% 0.29% 26.04% $12,604.37 $ 35.73

6 34.01% 0.29% 31.98% $13,198.03 $ 37.41

7 40.71% 0.29% 38.20% $13,819.66 $ 39.18

8 47.75% 0.29% 44.71% $14,470.57 $ 41.02

9 55.13% 0.29% 51.52% $15,152.13 $ 42.95

10 62.89% 0.29% 58.66% $15,865.80 $ 44.98

Total $354.46

42 | Appendix

Notes

Notes

Notes

Notes

Notes

To Get More Information

Shareholder reports — These includecommentary from the fund’smanagement team about recent marketconditions and the effects of the fund’sstrategies on its performance. They alsohave detailed performance figures, a listof everything the fund owns, and itsfinancial statements. Shareholders getthese reports automatically.

Statement of Additional Information

(SAI) — This tells you more about thefund’s features and policies, includingadditional risk information. The SAI isincorporated by reference into thisdocument (meaning that it’s legally partof this prospectus).

For a free copy of any of thesedocuments or to request otherinformation about the fund, call(800) 730-1313, or contact DWS

Investments at the address listed below.The fund’s SAI and shareholder reportsare also available through the DWSInvestments Web site atwww.moneyfunds.deam-us.db.com.These documents and other informationabout the fund are available from theEDGAR Database on the SEC’s Internetsite at www.sec.gov. If you like, you mayobtain copies of this information, afterpaying a copying fee, by e-mailing arequest to [email protected] or bywriting the SEC at the address listedbelow. You can also review and copythese documents and other informationabout the fund, including the fund’s SAI,at the SEC’s Public Reference Room inWashington, D.C. Information on theoperation of the SEC’s Public ReferenceRoom may be obtained by calling (800)SEC-0330.

DWS Investments SEC Distributor

PO Box 219210Kansas City, MO 64121-9210www.moneyfunds.deam-us.db.com(800) 730-1313

100 F Street, N.E.Washington, D.C.20549-0102www.sec.gov(800) SEC-0330

DWS Investments Distributors,Inc.222 South Riverside PlazaChicago, IL 60606-5808(800) 621-1148

SEC File Number:

DWS Money Market Trust DWS Money Market Series 811-03495

(05/01/09) 403-2-106

Prospectus - DWS Money Market Series, Institutional Shares · investing in high quality short-term money market instruments. Although the fund seeks to maintain a share price of $1.00

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