485BPOS

1933 Act File No.	2-75670
1940 Act File No.	811-3375

Form N-1A

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933
	Pre-Effective Amendment No.
	Post-Effective Amendment No.	55
and/or
REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940
	Amendment No.	51

FEDERATED GNMA TRUST

(Exact Name of Registrant as Specified in Charter)

Federated Investors Funds

4000 Ericsson Drive

Warrendale, PA 15086-7561

(Address of Principal Executive Offices)

(412) 288-1900

(Registrant’s Telephone Number, including Area Code)

John W. McGonigle, Esquire

Federated Investors Tower

Pittsburgh, Pennsylvania 15222-3779

(Name and Address of Agent for Service)

It is proposed that this filing will become effective (check appropriate box):
X	immediately upon filing pursuant to paragraph (b)
	on	pursuant to paragraph (b)
	60 days after filing pursuant to paragraph (a)(1)
	on	pursuant to paragraph (a)(1)
	75 days after filing pursuant to paragraph (a)(2)
	on	pursuant to paragraph (a)(2) of Rule 485
If appropriate, check the following box:
	This post-effective amendment designates a new effective date for a previously filed post-effective amendment.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, and the Investment Company Act of 1940, the Registrant, FEDERATED GNMA TRUST certifies that it meets all of the requirements for effectiveness of this Amendment to its Registration Statement pursuant to Rule 485(b) under the Securities Act of 1933 and has duly caused this Amendment to its Registration Statement to be signed on its behalf by the undersigned, duly authorized, in the City of Pittsburgh and Commonwealth of Pennsylvania, on the 9^th day of April, 2014.

FEDERATED GNMA TRUST

BY: /s/ Stacey C. Palmer

Stacey C. Palmer, Assistant Secretary

Pursuant to the requirements of the Securities Act of 1933, this Amendment to its Registration Statement has been signed below by the following person in the capacity and on the date indicated:

NAME	TITLE	DATE
BY: /s/ Stacy C. Palmer Assistant Secretary	Attorney In Fact For the Persons Listed Below	April 9, 2014
John F. Donahue *	Trustee
J. Christopher Donahue *	President and Trustee (Principal Executive Officer)
Lori A. Hensler, CPA*	Treasurer (Principal Financial Officer)
John T. Collins*	Trustee
Maureen Lally-Green*	Trustee
Peter E. Madden*	Trustee
Charles F. Mansfield, Jr.*	Trustee
Thomas O’Neill*	Trustee
P. Jerome Richey*	Trustee
John S. Walsh*	Trustee
*By Power of Attorney

FEDERATED GNMA TRUST

Post-Effective Amendment No. 55

This Post-Effective Amendment is filed for the sole purpose of submitting the XBRL Interactive Data File exhibits for the Risk/Return Summary of the above-named Fund filed as part of Post-Effective Amendment No. 54 on March 28, 2014.  The exhibits filed herewith do not constitute the complete publicly filed disclosure for the Fund, and should be used in conjunction with the complete prospectus for the Fund.

Exhibit List for Interactive Data File Submissions.

EX-101.INS	INSTANCE
EX-101.SCH	SCHEMA
EX-101.CAL	CALCULATION LINKBASE
EX-101.DEF	DEFINITION LINKBASE
EX-101.LAB	LABEL LINKBASE
EX-101.PRE	PRESENTATION LINKBASE

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	FEDERATED GNMA TRUST
Prospectus Date	rr_ProspectusDate	Mar. 31, 2014
Document Creation Date	dei_DocumentCreationDate	Mar. 28, 2014

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	FEDERATED GNMA TRUST
Prospectus Date	rr_ProspectusDate	Mar. 31, 2014
FEDERATED GNMA TRUST
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	Federated GNMA Trust (the "Fund")
Objective [Heading]	rr_ObjectiveHeading	RISK/RETURN SUMMARY: INVESTMENT OBJECTIVE
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund's investment objective is current income.
Expense [Heading]	rr_ExpenseHeading	RISK/RETURN SUMMARY: FEES AND EXPENSES
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	This table describes the fees and expenses that you may pay if you buy and hold the Fund's Institutional Shares (IS) or Service Shares (SS).
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	Shareholder Fees (fees paid directly from your investment)
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	April 1, 2015
Fee Waiver Or Reimbursement Over Assets, Later Of Termination Or Next Effective Prospectus	fgnmat_FeeWaiverOrReimbursementOverAssetsLaterOfTerminationOrNextEffectiveProspectus	up to but not including the later of (the "Termination Date"): (a) April 1, 2015; or (b) the date of the Fund's next effective Prospectus.
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	Portfolio Turnover
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	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 114% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	114.00%
Expense Example [Heading]	rr_ExpenseExampleHeading	Example
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	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. 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:
Strategy [Heading]	rr_StrategyHeading	RISK/RETURN SUMMARY: INVESTMENTS, RISKS and PERFORMANCE What is the Fund's Main Investment Strategy?
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	Under normal market conditions, the Fund invests primarily in mortgage-backed securities guaranteed by the Government National Mortgage Association (GNMA), U.S. Treasury securities and related derivative instruments. The Fund may also seek to increase its income by engaging in dollar-roll transactions. The Fund buys and sells portfolio securities based primarily on its market outlook and analysis of how securities may perform under different market conditions. The Fund evaluates its investment strategy by comparing the performance and composition of the Fund's portfolio to the performance and composition of an index composed of mortgage-backed securities guaranteed by GNMA. The Fund typically seeks to maintain an overall average dollar-weighted portfolio duration that is within 20% above or below the Barclays GNMA Index (the "Index") (formerly, Barclays Capital GNMA Index). At times, the Adviser's calculation of portfolio duration may result in variances outside this range. Duration is a measure of the price volatility of a fixed-income security as a result of changes in market rates of interest, based on the weighted average timing of the instrument's expected fixed interest and principal payments. The Adviser seeks to create a portfolio, consisting of GNMA Mortgage-Backed Securities (MBS), U.S. Treasury securities and related derivative instruments that outperforms the Index. Based on fundamental analysis, the Adviser will consider a variety of factors when making decisions to purchase or sell particular securities or derivative contracts. The Fund may, but is not required to, use derivative instruments, which are instruments that have a value based on another instrument, exchange rate or index, and may be used as substitutes for securities in which the Fund can invest, or to hedge against a potential loss in the underlying asset. There can be no assurance that the Fund's use of derivative instruments will work as intended. Because the Fund refers to GNMA in its name, it will notify shareholders at least 60 days in advance of any change in its investment policies that would enable the Fund to invest, under normal circumstances, less than 80% of its net assets (plus any borrowings for investment purposes) in GNMA investments.
Risk [Heading]	rr_RiskHeading	What are the Main Risks of Investing in the Fund?
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	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: MBS Risk. A rise in interest rates may cause the value of MBS held by the Fund to decline. The Fund's investments in collateralized mortgage obligations (CMOs) may entail greater market, prepayment and liquidity risks than other MBS. Interest Rate Risk. Prices of fixed-income securities generally fall when interest rates rise. Prepayment Risk. When homeowners prepay their mortgages in response to lower interest rates, the Fund will be required to reinvest the proceeds at the lower interest rates available. Also, when interest rates fall, the prices of MBS may not rise to as great an extent as those of other fixed-income securities due to the potential prepayment of higher interest mortgages. Liquidity Risk. The CMOs in which the Fund invests may be less readily marketable and may be subject to greater fluctuation in price than other securities. Leverage Risk. Leverage risk is created when an investment exposes the Fund to a level of risk that exceeds the amount invested. Changes in the value of such an investment magnify the Fund's risk of loss and potential for gain. Credit Risk. It is possible that interest or principal on securities will not be paid when due. Such non-payment or default may reduce the value of the Fund's portfolio holdings, its share price and its performance. Counterparty Risk. Counterparty risk includes the possibility that a party to a transaction involving the Fund will fail to meet its obligations. This could cause the Fund to lose the benefit of the transaction or prevent the Fund from selling or buying other securities to implement its investment strategy. Risk of Investing in Derivative Instruments. The Fund's exposure to derivative contracts and hybrid instruments (either directly or through its investment in another investment company) involves risks different from, or possibly greater than, the risks associated with investing directly in securities and other traditional investments. The use of derivatives can lead to losses because of adverse movements in the price or value of the asset, index, rate or instrument underlying a derivative, due to failure of a counterparty, or the failure of the counterparty to meet its obligations under the contract, or due to tax or regulatory constraints. Derivatives may create investment leverage in the Fund, which magnifies the Fund's exposure to the underlying investment. Derivative instruments may be difficult to value, may be illiquid and may be subject to wide swings in valuation caused by changes in the value of the underlying instrument. Over-the-counter derivative contracts generally carry greater liquidity risk than exchange-traded contracts. The loss on derivative transactions may substantially exceed the initial investment. Asset Segregation Risk. The requirement to secure its obligations in connection with certain transactions, including derivatives or other transactions that expose it to an obligation of another party, by owning underlying assets, entering into offsetting transactions or setting aside cash or liquid assets, may cause the Fund to miss favorable trading opportunities, or to realize losses on such offsetting transactions. Short Sale Risk. The Fund may incur a loss as a result of a short sale if the price of the security increases between the date of the sale and the date on which the Fund repurchases the security. The risk is that the securities price moves in the opposite direction than expected causing the Fund to lose money. Technology Risk. The Adviser uses various technologies in managing the Fund, consistent with its investment objective and strategy described in this prospectus. For example, proprietary and third-party data and systems are utilized to support decision making for the Fund.  Data imprecision, software or other technology malfunctions, programming inaccuracies and similar circumstances may impair the performance of these systems, which may negatively affect Fund performance. 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.
Risk Lose Money [Text]	rr_RiskLoseMoney	All mutual funds take investment risks. Therefore, it is possible to lose money by investing in the Fund.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	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.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Performance: Bar Chart and Table Risk/Return Bar Chart
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	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 for each class 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.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The bar chart shows the variability of the Fund's IS class total returns on a calendar year-by-year basis.
Performance Additional Market Index [Text]	rr_PerformanceAdditionalMarketIndex	The Barclays GNMA Index is an unmanaged index comprised of all fixed securities mortgage pools by GNMA, including GNMA Graduated Payment Mortgages. Lipper figures represent the average of the total returns reported by all mutual funds designated by Lipper, Inc., as falling into the respective category and is not adjusted to reflect any sales charges. These total returns are reported net of expenses and other fees that the Securities and Exchange Commission requires to be reflected in a mutual fund's performance.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	1-800-341-7400
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	FederatedInvestors.com
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	The Fund's performance will fluctuate, and past performance (before and after taxes) is not necessarily an indication of future results.
Bar Chart [Heading]	rr_BarChartHeading	Federated GNMA Trust -  IS Class
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Within the periods shown in the bar chart, the Fund's IS class highest quarterly return was 3.54% (quarter ended December 31, 2008). Its lowest quarterly return was (2.96)% (quarter ended June 30, 2013).
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Return Table
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	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.
Performance Table Not Relevant to Tax Deferred	rr_PerformanceTableNotRelevantToTaxDeferred	After-tax returns are not relevant to investors holding Shares through a 401(k) plan, an Individual Retirement Account or other tax-advantaged investment plan.
Performance Table One Class of after Tax Shown [Text]	rr_PerformanceTableOneClassOfAfterTaxShown	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. Actual after-tax returns are shown only for the IS class, and after tax returns for the SS class will differ from those shown for the IS class.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	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. Actual after-tax returns are shown only for the IS class, and after tax returns for the SS class will differ from those shown for the 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 plan. (For the Period Ended December 31, 2013)
FEDERATED GNMA TRUST | IS
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum Deferred Sales Charge (Load) (as a percentage of original purchase price or redemption proceeds, as applicable)	rr_MaximumDeferredSalesChargeOverOther	none
Maximum Sales Charge (Load) Imposed on Reinvested Dividends (and other Distributions) (as a percentage of offering price)	rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther	none
Redemption Fee (as a percentage of amount redeemed, if applicable)	rr_RedemptionFeeOverRedemption	none
Exchange Fee	rr_ExchangeFeeOverRedemption	none
Management Fee	rr_ManagementFeesOverAssets	0.40%
Distribution (12b-1) Fee	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	0.48%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.88%
Fee Waivers and/or Expense Reimbursements	rr_FeeWaiverOrReimbursementOverAssets	0.21%	[1]
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	rr_NetExpensesOverAssets	0.67%
1 Year	rr_ExpenseExampleYear01	$ 90
3 Years	rr_ExpenseExampleYear03	281
5 Years	rr_ExpenseExampleYear05	488
10 Years	rr_ExpenseExampleYear10	1,084
2004	rr_AnnualReturn2004	3.69%
2005	rr_AnnualReturn2005	2.61%
2006	rr_AnnualReturn2006	3.88%
2007	rr_AnnualReturn2007	6.15%
2008	rr_AnnualReturn2008	6.95%
2009	rr_AnnualReturn2009	5.30%
2010	rr_AnnualReturn2010	5.66%
2011	rr_AnnualReturn2011	6.32%
2012	rr_AnnualReturn2012	1.70%
2013	rr_AnnualReturn2013	(2.59%)
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	highest quarterly return
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Dec. 31, 2008
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	3.54%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	lowest quarterly return
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Jun. 30, 2013
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(2.96%)
1 Year	rr_AverageAnnualReturnYear01	(2.59%)
5 Years	rr_AverageAnnualReturnYear05	3.22%
10 Years	rr_AverageAnnualReturnYear10	3.93%
FEDERATED GNMA TRUST | SS
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum Deferred Sales Charge (Load) (as a percentage of original purchase price or redemption proceeds, as applicable)	rr_MaximumDeferredSalesChargeOverOther	none
Maximum Sales Charge (Load) Imposed on Reinvested Dividends (and other Distributions) (as a percentage of offering price)	rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther	none
Redemption Fee (as a percentage of amount redeemed, if applicable)	rr_RedemptionFeeOverRedemption	none
Exchange Fee	rr_ExchangeFeeOverRedemption	none
Management Fee	rr_ManagementFeesOverAssets	0.40%
Distribution (12b-1) Fee	rr_DistributionAndService12b1FeesOverAssets	none	[2]
Other Expenses	rr_OtherExpensesOverAssets	0.48%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.88%
Fee Waivers and/or Expense Reimbursements	rr_FeeWaiverOrReimbursementOverAssets	0.05%	[1]
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	rr_NetExpensesOverAssets	0.83%
1 Year	rr_ExpenseExampleYear01	90
3 Years	rr_ExpenseExampleYear03	281
5 Years	rr_ExpenseExampleYear05	488
10 Years	rr_ExpenseExampleYear10	$ 1,084
1 Year	rr_AverageAnnualReturnYear01	(2.65%)
5 Years	rr_AverageAnnualReturnYear05	3.07%
10 Years	rr_AverageAnnualReturnYear10	3.77%
FEDERATED GNMA TRUST | Return After Taxes on Distributions | IS
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(3.56%)
5 Years	rr_AverageAnnualReturnYear05	1.92%
10 Years	rr_AverageAnnualReturnYear10	2.39%
FEDERATED GNMA TRUST | Return After Taxes on Distributions and Sale of Fund Shares | IS
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(1.46%)
5 Years	rr_AverageAnnualReturnYear05	2.02%
10 Years	rr_AverageAnnualReturnYear10	2.47%
FEDERATED GNMA TRUST | Barclays GNMA Index (reflects no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(2.12%)	[3]
5 Years	rr_AverageAnnualReturnYear05	3.99%	[3]
10 Years	rr_AverageAnnualReturnYear10	4.69%	[3]
FEDERATED GNMA TRUST | Lipper GNMA Funds Average
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(2.83%)	[4]
5 Years	rr_AverageAnnualReturnYear05	4.06%	[4]
10 Years	rr_AverageAnnualReturnYear10	4.10%	[4]

[1] 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, extraordinary expenses and proxy-related expenses paid by the Fund, if any) paid by the Fund's IS and SS classes (after the voluntary waivers and/or reimbursements) will not exceed 0.67% and 0.83% (the "Fee Limit"), respectively, up to but not including the later of (the "Termination Date"): (a) April 1, 2015; 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 Trustees.

[2] The Fund has adopted a Distribution (12b-1) Plan for its SS class pursuant to which the SS class of the Fund may incur or charge a Distribution (12b-1) fee of up to a maximum amount of 0.05%. No such fee is currently incurred or charged by the SS class of the Fund. The SS class of the Fund will not incur or charge such a Distribution (12b-1) fee until such time as approved by the Fund's Board of Trustees (the "Trustees").

[3] The Barclays GNMA Index is an unmanaged index comprised of all fixed securities mortgage pools by GNMA, including GNMA Graduated Payment Mortgages.

[4] Lipper figures represent the average of the total returns reported by all mutual funds designated by Lipper, Inc., as falling into the respective category and is not adjusted to reflect any sales charges. These total returns are reported net of expenses and other fees that the Securities and Exchange Commission requires to be reflected in a mutual fund's performance.

XML

FEDERATED GNMA TRUST

Federated GNMA Trust (the "Fund")

RISK/RETURN SUMMARY: INVESTMENT OBJECTIVE

The Fund's investment objective is current income.

RISK/RETURN SUMMARY: FEES AND EXPENSES

This table describes the fees and expenses that you may pay if you buy and hold the Fund's Institutional Shares (IS) or Service Shares (SS).

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees FEDERATED GNMA TRUST	IS	SS
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none	none
Maximum Deferred Sales Charge (Load) (as a percentage of original purchase price or redemption proceeds, as applicable)	none	none
Maximum Sales Charge (Load) Imposed on Reinvested Dividends (and other Distributions) (as a percentage of offering price)	none	none
Redemption Fee (as a percentage of amount redeemed, if applicable)	none	none
Exchange Fee	none	none

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses FEDERATED GNMA TRUST		IS	SS
Management Fee		0.40%	0.40%
Distribution (12b-1) Fee		none	none	[1]
Other Expenses		0.48%	0.48%
Total Annual Fund Operating Expenses		0.88%	0.88%
Fee Waivers and/or Expense Reimbursements	[2]	0.21%	0.05%
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements		0.67%	0.83%

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. 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:

Expense Example FEDERATED GNMA TRUST (USD $)	1 Year	3 Years	5 Years	10 Years
IS	90	281	488	1,084
SS	90	281	488	1,084

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 114% of the average value of its portfolio.

RISK/RETURN SUMMARY: INVESTMENTS, RISKS and PERFORMANCE

What is the Fund's Main Investment Strategy?

Under normal market conditions, the Fund invests primarily in mortgage-backed securities guaranteed by the Government National Mortgage Association (GNMA), U.S. Treasury securities and related derivative instruments. The Fund may also seek to increase its income by engaging in dollar-roll transactions. The Fund buys and sells portfolio securities based primarily on its market outlook and analysis of how securities may perform under different market conditions. The Fund evaluates its investment strategy by comparing the performance and composition of the Fund's portfolio to the performance and composition of an index composed of mortgage-backed securities guaranteed by GNMA.

The Fund typically seeks to maintain an overall average dollar-weighted portfolio duration that is within 20% above or below the Barclays GNMA Index (the "Index") (formerly, Barclays Capital GNMA Index). At times, the Adviser's calculation of portfolio duration may result in variances outside this range. Duration is a measure of the price volatility of a fixed-income security as a result of changes in market rates of interest, based on the weighted average timing of the instrument's expected fixed interest and principal payments. The Adviser seeks to create a portfolio, consisting of GNMA Mortgage-Backed Securities (MBS), U.S. Treasury securities and related derivative instruments that outperforms the Index.

Based on fundamental analysis, the Adviser will consider a variety of factors when making decisions to purchase or sell particular securities or derivative contracts. The Fund may, but is not required to, use derivative instruments, which are instruments that have a value based on another instrument, exchange rate or index, and may be used as substitutes for securities in which the Fund can invest, or to hedge against a potential loss in the underlying asset. There can be no assurance that the Fund's use of derivative instruments will work as intended.

Because the Fund refers to GNMA in its name, it will notify shareholders at least 60 days in advance of any change in its investment policies that would enable the Fund to invest, under normal circumstances, less than 80% of its net assets (plus any borrowings for investment purposes) in GNMA investments.

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:

• MBS Risk. A rise in interest rates may cause the value of MBS held by the Fund to decline. The Fund's investments in collateralized mortgage obligations (CMOs) may entail greater market, prepayment and liquidity risks than other MBS.

• Interest Rate Risk. Prices of fixed-income securities generally fall when interest rates rise.

• Prepayment Risk. When homeowners prepay their mortgages in response to lower interest rates, the Fund will be required to reinvest the proceeds at the lower interest rates available. Also, when interest rates fall, the prices of MBS may not rise to as great an extent as those of other fixed-income securities due to the potential prepayment of higher interest mortgages.

• Liquidity Risk. The CMOs in which the Fund invests may be less readily marketable and may be subject to greater fluctuation in price than other securities.

• Leverage Risk. Leverage risk is created when an investment exposes the Fund to a level of risk that exceeds the amount invested. Changes in the value of such an investment magnify the Fund's risk of loss and potential for gain.

• Credit Risk. It is possible that interest or principal on securities will not be paid when due. Such non-payment or default may reduce the value of the Fund's portfolio holdings, its share price and its performance.

• Counterparty Risk. Counterparty risk includes the possibility that a party to a transaction involving the Fund will fail to meet its obligations. This could cause the Fund to lose the benefit of the transaction or prevent the Fund from selling or buying other securities to implement its investment strategy.

• Risk of Investing in Derivative Instruments. The Fund's exposure to derivative contracts and hybrid instruments (either directly or through its investment in another investment company) involves risks different from, or possibly greater than, the risks associated with investing directly in securities and other traditional investments. The use of derivatives can lead to losses because of adverse movements in the price or value of the asset, index, rate or instrument underlying a derivative, due to failure of a counterparty, or the failure of the counterparty to meet its obligations under the contract, or due to tax or regulatory constraints. Derivatives may create investment leverage in the Fund, which magnifies the Fund's exposure to the underlying investment. Derivative instruments may be difficult to value, may be illiquid and may be subject to wide swings in valuation caused by changes in the value of the underlying instrument. Over-the-counter derivative contracts generally carry greater liquidity risk than exchange-traded contracts. The loss on derivative transactions may substantially exceed the initial investment.

• Asset Segregation Risk. The requirement to secure its obligations in connection with certain transactions, including derivatives or other transactions that expose it to an obligation of another party, by owning underlying assets, entering into offsetting transactions or setting aside cash or liquid assets, may cause the Fund to miss favorable trading opportunities, or to realize losses on such offsetting transactions.

• Short Sale Risk. The Fund may incur a loss as a result of a short sale if the price of the security increases between the date of the sale and the date on which the Fund repurchases the security. The risk is that the securities price moves in the opposite direction than expected causing the Fund to lose money.

• Technology Risk. The Adviser uses various technologies in managing the Fund, consistent with its investment objective and strategy described in this prospectus. For example, proprietary and third-party data and systems are utilized to support decision making for the Fund.  Data imprecision, software or other technology malfunctions, programming inaccuracies and similar circumstances may impair the performance of these systems, which may negatively affect Fund performance.

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 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 for each class 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.

Federated GNMA Trust -  IS Class

Within the periods shown in the bar chart, the Fund's IS class highest quarterly return was 3.54% (quarter ended December 31, 2008). Its lowest quarterly return was (2.96)% (quarter ended June 30, 2013).

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. Actual after-tax returns are shown only for the IS class, and after tax returns for the SS class will differ from those shown for the 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 plan.

(For the Period Ended December 31, 2013)

Average Annual Total Returns FEDERATED GNMA TRUST		1 Year	5 Years	10 Years
IS		(2.59%)	3.22%	3.93%
IS Return After Taxes on Distributions		(3.56%)	1.92%	2.39%
IS Return After Taxes on Distributions and Sale of Fund Shares		(1.46%)	2.02%	2.47%
SS		(2.65%)	3.07%	3.77%
Barclays GNMA Index (reflects no deduction for fees, expenses or taxes)	[1]	(2.12%)	3.99%	4.69%
Lipper GNMA Funds Average	[2]	(2.83%)	4.06%	4.10%

[1] The Fund has adopted a Distribution (12b-1) Plan for its SS class pursuant to which the SS class of the Fund may incur or charge a Distribution (12b-1) fee of up to a maximum amount of 0.05%. No such fee is currently incurred or charged by the SS class of the Fund. The SS class of the Fund will not incur or charge such a Distribution (12b-1) fee until such time as approved by the Fund's Board of Trustees (the "Trustees").

[2] 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, extraordinary expenses and proxy-related expenses paid by the Fund, if any) paid by the Fund's IS and SS classes (after the voluntary waivers and/or reimbursements) will not exceed 0.67% and 0.83% (the "Fee Limit"), respectively, up to but not including the later of (the "Termination Date"): (a) April 1, 2015; 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 Trustees.

[1] The Barclays GNMA Index is an unmanaged index comprised of all fixed securities mortgage pools by GNMA, including GNMA Graduated Payment Mortgages.

[2] Lipper figures represent the average of the total returns reported by all mutual funds designated by Lipper, Inc., as falling into the respective category and is not adjusted to reflect any sales charges. These total returns are reported net of expenses and other fees that the Securities and Exchange Commission requires to be reflected in a mutual fund's performance.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Document Type	dei_DocumentType	485BPOS
Document Period End Date	dei_DocumentPeriodEndDate	Jan. 31, 2014
Registrant Name	dei_EntityRegistrantName	FEDERATED GNMA TRUST
Central Index Key	dei_EntityCentralIndexKey	0000357110
Amendment Flag	dei_AmendmentFlag	false
Document Creation Date	dei_DocumentCreationDate	Mar. 28, 2014
Document Effective Date	dei_DocumentEffectiveDate	Mar. 31, 2014
Prospectus Date	rr_ProspectusDate	Mar. 31, 2014