Federated Investors, Inc.

Summary Prospectus

September 30, 2012

Share Class	Ticker
A	QAACX
C	QCACX
R	QKACX
Institutional	QIACX

Federated MDT All Cap Core Fund

A Portfolio of Federated MDT Series

Before you invest, you may want to review the Fund's Prospectus, which contains more information about the Fund and its risks. You can find the Fund's Prospectus and other information about the Fund, including the Statement of Additional Information and most recent reports to shareholders, online at FederatedInvestors.com/prospectus. You can also get this information at no cost by calling 1-800-341-7400 or by sending an email request to services@federatedinvestors.com or from a financial intermediary through which Shares of the Fund may be bought or sold. The Fund's Prospectus and Statement of Additional Information, both dated September 30, 2012, are incorporated by reference into this Summary Prospectus.

A mutual fund seeking long-term capital appreciation by investing primarily in the common stock of U.S. companies.

As with all mutual funds, the Securities and Exchange Commission (SEC) has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

Not FDIC Insured • May Lose Value • No Bank Guarantee

Fund Summary Information

Federated MDT All Cap Core Fund (the “Fund”)

RISK/RETURN SUMMARY: INVESTMENT OBJECTIVE

The Fund's investment objective is long-term capital appreciation.

RISK/RETURN SUMMARY: FEES AND EXPENSES

This table describes the fees and expenses that you may pay if you buy and hold Fund's Class A Shares (A), Class C Shares (C), Class R Shares (R) and Institutional Shares (IS). You may qualify for certain sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in certain classes (e.g., A class) of Federated Funds. More information about these and other discounts is available from your financial professional and in the “What Do Shares Cost?” section of the Prospectus on page 7.

Shareholder Fees (fees paid directly from your investment)	A	C	R	IS
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	5.50%	None	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of original purchase price or redemption proceeds, as applicable)	0.00%	1.00%	None	None
Maximum Sales Charge (Load) Imposed on Reinvested Dividends (and other Distributions) (as a percentage of offering price)	None	None	None	None
Redemption Fee (as a percentage of amount redeemed, if applicable)	None	None	None	None
Exchange Fee	None	None	None	None
Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fee	0.75%	0.75%	0.75%	0.75%
Distribution (12b-1) Fee	0.05%	0.75%	0.50%	None
Other Expenses	1.00%	1.01%	0.85%	0.62%
Acquired Fund Fees and Expenses	0.01%	0.01%	0.01%	0.01%
Total Annual Fund Operating Expenses	1.81%	2.52%	2.11%	1.38%
Fee Waivers and/or Expense Reimbursements¹	0.45%	0.36%	0.25%	0.27%
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	1.36%	2.16%	1.86%	1.11%

The Adviser and its affiliates have voluntarily agreed to waive their fees and/or reimburse expenses so that the total annual fund operating expenses (excluding Acquired Fund Fees and Expenses) paid by the Fund's A, C, R and IS classes (after the voluntary waivers and/or reimbursements) will not exceed 1.35%, 2.15%, 1.85% and 1.10% (the “Fee Limit”), respectively, up to but not including the later of (the “Termination Date”): (a) October 1, 2013; or (b) the date of the Fund's next effective Prospectus. While the Adviser and its affiliates currently do not anticipate terminating or increasing these arrangements prior to the Termination Date, these arrangements may only be terminated or the Fee Limit increased prior to the Termination Date with the agreement of the Fund's Board of Trustees.

Example

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds.

The Example assumes that you invest $10,000 for the time periods indicated and then redeem all of your Shares at the end of those periods. Expenses assuming no redemption are also shown. The Example also assumes that your investment has a 5% return each year and that operating expenses are as shown in the table above and remain the same. Although your actual costs and returns may be higher or lower, based on these assumptions your costs would be:

Share Class	1 Year	3 Years	5 Years	10 Years
A:
Expenses assuming redemption	$724	$1,088	$1,476	$2,560
Expenses assuming no redemption	$724	$1,088	$1,476	$2,560
C:
Expenses assuming redemption	$355	$785	$1,340	$2,856
Expenses assuming no redemption	$255	$785	$1,340	$2,856
R:
Expenses assuming redemption	$214	$661	$1,134	$2,441
Expenses assuming no redemption	$214	$661	$1,134	$2,441
IS:
Expenses assuming redemption	$141	$437	$755	$1,657
Expenses assuming no redemption	$141	$437	$755	$1,657

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund Shares are held in a taxable account. These costs, which are not reflected in Annual Fund Operating Expenses or in the Example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 164% of the average value of its portfolio.

RISK/RETURN SUMMARY: INVESTMENTS, RISKS and PERFORMANCE

What are the Fund's Main Investment Strategies?

The Fund seeks to achieve its objective by investing primarily in the common stock of U.S. companies. The Fund's investment adviser's investment strategy utilizes a whole market, all-cap/all-style approach by selecting most of its investments from companies listed in the Russell 3000^® Index, an index that measures the performance of the 3,000 largest U.S. companies by market capitalization representing approximately 98% of the investable domestic equity market. As of July 31, 2012, companies in the Russell 3000^® Index ranged in market capitalization from $46 million to $571 billion. As more fully described in this Prospectus, the Fund's investments may include, but are not limited to, equity securities of domestic issuers.

The Adviser implements its strategy using a quantitative computer model driven by fundamental stock selection variables, including company valuations, profit trends and earnings risks. This process, called the Optimum Q process, seeks to impose strict discipline over stock selection, unimpeded by market or manager psychology. It seeks to maximize compound annual return while controlling risk.

The Fund actively trades its portfolio securities in an attempt to achieve its investment objective. Active trading will cause the Fund to have an increased portfolio turnover rate, which is likely to generate shorter-term gains (losses) for its shareholders, which are taxed at a higher rate than longer-term gains (losses). Actively trading portfolio securities increases the Fund's trading costs and may have an adverse impact on the Fund's performance.

What are the Main Risks of Investing in the Fund?

All mutual funds take investment risks. Therefore, it is possible to lose money by investing in the Fund. The primary factors that may reduce the Fund's returns include:

■	Stock Market Risk. The value of equity securities in the Fund's portfolio will fluctuate and, as a result, the Fund's Share price may decline suddenly or over a sustained period of time.
■	Small, Medium and Large Sized Companies Risk. The Fund may invest in any size company including small and mid-size companies. Although diminished in larger cap companies, the risks of investing in all companies include business failure and reliance on erroneous reports. You should expect that the value of the Fund's shares will be more volatile than a fund that invests exclusively in large-capitalization companies.
■	Risk Related to Investing for Growth. Due to their relatively high valuations, growth stocks are typically more volatile than value stocks. Additionally, growth stocks may not pay dividends or may pay lower dividends than value stocks.
■	Risk Related to Investing for Value. Due to their relatively low valuations, value stocks are typically less volatile than growth stocks. Additionally, value stocks tend to have higher dividends than growth stocks. This means they depend less on price changes for returns and may lag behind growth stocks in an up market.
■	Sector Risk. Because the Fund may allocate relatively more assets to certain industry sectors than others, the Fund's performance may be more susceptible to any developments which affect those sectors emphasized by the Fund.
■	Liquidity Risk. Trading opportunities are more limited for equity securities that are not widely held. This may make it more difficult to sell or buy a security at a favorable price or time. Consequently, the Fund may have to accept a lower price to sell a security, sell other securities to raise cash or give up an investment opportunity, any of which could have a negative effect on the Fund's performance. Infrequent trading of securities may also lead to an increase in their price volatility.
■	Quantitative Modeling Risk. The Fund employs quantitative models as a management technique. These models examine multiple economic factors using various proprietary and third-party data. The results generated by

quantitative analysis may perform differently than expected and may negatively affect Fund performance for various reasons (for example, human judgment, data imprecision, software or other technology malfunctions, or programming inaccuracies).

The Shares offered by this Prospectus are not deposits or obligations of any bank, are not endorsed or guaranteed by any bank and are not insured or guaranteed by the U.S. government, the Federal Deposit Insurance Corporation, the Federal Reserve Board or any other government agency.

Performance: Bar Chart and Table

Risk/Return Bar Chart

The Fund is the successor to the MDT All Cap Core Fund pursuant to a reorganization that was completed on or about the close of business on December 8, 2006. Prior to that date, the Fund had no investment operations. Accordingly, the performance information, including information on fees and expenses, and financial information provided in this Prospectus for periods prior to December 11, 2006, is historical information for the MDT All Cap Core Fund. The MDT All Cap Core Fund was managed by MDT Advisers and had similar investment objectives and strategies as the Fund.

The bar chart and performance table below reflect historical performance data for the Fund and are intended to help you analyze the Fund's investment risks in light of its historical returns. The bar chart shows the variability of the Fund's IS class total returns on a calendar year-by-year basis. The Average Annual Total Return table shows returns averaged over the stated periods, and includes comparative performance information. The Fund's performance will fluctuate, and past performance (before and after taxes) is not necessarily an indication of future results. Updated performance information for the Fund is available under the “Products” section at FederatedInvestors.com or by calling 1-800-341-7400.

The Fund's IS class total return for the six-month period from January 1, 2012 to June 30, 2012, was 7.32%.

Within the periods shown in the bar chart, the Fund's IS class highest quarterly return was 14.03% (quarter ended June 30, 2009). Its lowest quarterly return was (26.33)% (quarter ended December 31, 2008).

Average Annual Total Return Table

In addition to Return Before Taxes, Return After Taxes is shown for the Fund's IS class to illustrate the effect of federal taxes on Fund returns. After-tax returns are shown only for IS class, and after-tax returns for A, C and R classes will differ from those shown for IS class. Actual after-tax returns depend on each investor's personal tax situation, and are likely to differ from those shown. After-tax returns are calculated using a standard set of assumptions. The stated returns assume the highest historical federal income and capital gains tax rates. These after-tax returns do not reflect the effect of any applicable state and local taxes. After-tax returns are not relevant to investors holding shares through a 401(k) plan, an Individual Retirement Account or other tax-advantaged investment plans.

(For the Period Ended December 31, 2011)

	1 Year	5 Years	Since Inception 10/1/2002¹
A:²
Return Before Taxes	(6.07)%	(5.38)%	4.33%
C:
Return Before Taxes	(2.44)%	(5.06)%	4.17%
R:
Return Before Taxes	(1.09)%	(4.70)%	4.50%
IS:
Return Before Taxes	(0.33)%	(4.03)%	5.25%
Return After Taxes on Distributions	(0.39)%	(4.47)%	4.49%
Return After Taxes on Distributions and Sale of Fund Shares	(0.21)%	(3.50)%	4.33%
Russell 3000^® Index³ (reflects no deduction for fees, expenses or taxes)	1.03%	(0.01)%	7.45%

1	The start of performance date was October 1, 2002. A class, C class and R class commenced operations on February 12, 2003, September 15, 2005 and December 12, 2006, respectively. Performance results shown before that date are for the IS class, but adjusted to reflect sales charges or the contingent deferred sales charge and expense applicable to each respective class.
2	The returns for A class have been restated to reflect the imposition of a front-end sales charge on purchases as of November 28, 2005.
3	The Russell 3000^® Index offers investors access to the broad U.S. equity universe representing approximately 98% of the U.S. market. The Russell 3000 is constructed to provide a comprehensive, unbiased and stable barometer of the broad market, and is completely reconstituted annually to ensure that new and growing equities are reflected. The index is unmanaged, and unlike the Fund, is not affected by cash flows. The Russell 3000^® is not adjusted to reflect sales charges, expenses or other fees that the Securities and Exchange Commission (SEC) requires to be reflected in the Fund's performance. It is not possible to invest directly in an index.

FUND MANAGEMENT

The Fund's Investment Adviser is Federated MDTA LLC.

Daniel J. Mahr, Managing Director of Research, has been the Fund's portfolio manager since August 2008.

Frederick L. Konopka, Portfolio and Trading Manager, has been the Fund's portfolio manager since August 2008.

Brian M. Greenberg, Research Manager, has been the Fund's portfolio manager since August 2008.

purchase and sale of fund shares

You may purchase, redeem or exchange Shares of the Fund on any day the New York Stock Exchange is open. Shares may be purchased through a financial intermediary or directly from the Fund, by wire or by check. Please note that certain purchase restrictions may apply. Redeem or exchange Shares through a financial intermediary or directly from the Fund by telephone at 1-800-341-7400 or by mail.

A & C Classes

The minimum investment amount for the Fund's A and C classes is generally $1,500 for initial investments and $100 for subsequent investments. The minimum initial and subsequent investment amounts for Individual Retirement Accounts are generally $250 and $100, respectively. There is no minimum initial or subsequent investment amount required for employer-sponsored retirement plans. The minimum investment for Systematic Investment Programs is $50.

R Class

The minimum initial and subsequent investment amounts for Individual Retirement Account rollovers into the Fund's R class are generally $250 and $100, respectively. There is no minimum initial or subsequent amount for employer-sponsored retirement plans. The minimum investment amount for Systematic Investment Programs is $50.

IS Class

The minimum initial investment amount for the Fund's IS class is generally $1,000,000 and there is no minimum subsequent investment amount. The minimum investment amount for Systematic Investment Programs is $50.

Tax Information

The Fund's distributions are taxable as ordinary income or capital gains except when your investment is through a 401(k) plan, an Individual Retirement Account or other tax-advantaged investment plan.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund and/or its related companies may pay the intermediary for the sale of Fund Shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary's website for more information.

Federated MDT All Cap Core Fund
Federated Investors Funds
4000 Ericsson Drive
Warrendale, PA 15086-7561

Federated Securities Corp., Distributor

Investment Company Act File No. 811-21904

CUSIP 31421R106
CUSIP 31421R205
CUSIP 31421R718
CUSIP 31421R304

Q450565 (9/12)