497

Stradley Ronon Stevens & Young, LLP
2600 One Commerce Square
Philadelphia, PA 19103
Telephone: (215) 564-8099
Facsimile: (215) 564-8120

March 6, 2013

VIA EDGAR

U.S. Securities and Exchange Commission
100 F Street, N.E.
Washington, D.C. 20549
Attn: Filing Desk

Re:	Delaware Group Income Funds (the “Registrant”)
	SEC File Nos. 002-37707 and 811-02071
	Rule 497(e) filing

Ladies and Gentlemen:

Enclosed for filing pursuant to Rule 497(e) under the Securities Act of 1933, as amended, (the “1933 Act”) are exhibits containing interactive data format risk/return summary information that reflect a supplement to the risk/return summary information contained in the prospectus dated November 28, 2012, for Delaware Extended Duration Bond Fund, a series of the Registrant, as filed pursuant to Rule 497(e) under the 1933 Act on February 15, 2013 (Accession Number: 0001206774-13-000629).

Please direct questions or comments relating to this filing to me at the above-referenced telephone number.

Very truly yours,

/s/ Jonathan M. Kopcsik

Jonathan M. Kopcsik

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Document Type

dei_DocumentType

Other

Document Period End Date

dei_DocumentPeriodEndDate

Feb. 15, 2013

Entity Registrant Name

dei_EntityRegistrantName

DELAWARE GROUP INCOME FUNDS

Entity Central Index Key

dei_EntityCentralIndexKey

0000027825

Amendment Flag

dei_AmendmentFlag

false

Document Creation Date

dei_DocumentCreationDate

Feb. 15, 2013

Document Effective Date

dei_DocumentEffectiveDate

Feb. 15, 2013

Prospectus Date

rr_ProspectusDate

Nov. 28, 2012

DELAWARE EXTENDED DURATION BOND FUND

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Delaware Extended Duration Bond Fund

Objective [Heading]

rr_ObjectiveHeading

What is the Fund’s investment objective?

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

Delaware Extended Duration Bond Fund seeks to provide investors with total return.

Expense [Heading]

rr_ExpenseHeading

What are the Fund’s fees and expenses?

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales-charge discounts if you and your family invest, or agree to invest in the future, at least $100,000 in Delaware Investments^® Funds. More information about these and other discounts is available from your financial advisor, in the Fund’s prospectus under the section entitled “About your account,” and in the Fund’s statement of additional information under the section entitled “Purchasing shares.”

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

2013-11-28

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 172% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

172.00%

Expense Breakpoint Discounts [Text]

rr_ExpenseBreakpointDiscounts

You may qualify for sales-charge discounts if you and your family invest, or agree to invest in the future, at least $100,000 in Delaware Investments^® Funds. More information about these and other discounts is available from your financial advisor, in the Fund’s prospectus under the section entitled “About your account,” and in the Fund’s statement of additional information under the section entitled “Purchasing shares.”

Expense Breakpoint, Minimum Investment Required [Amount]

rr_ExpenseBreakpointMinimumInvestmentRequiredAmount

100,000

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 in the Fund 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 reflects the applicable waivers and reimbursements for the 1-year contractual period and the total operating expenses without waivers for years 2 through 10. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example, No Redemption, By Year, Caption [Text]

rr_ExpenseExampleNoRedemptionByYearCaption

if not redeemed

Strategy [Heading]

rr_StrategyHeading

What are the Fund’s principal investment strategies?

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in corporate bonds. Our focus is on corporate bonds that have investment grade credit ratings from a nationally recognized statistical rating organization (NRSRO). The bonds we select for the portfolio are typically rated BBB- and above by Standard & Poor’s (S&P), Baa3 and above by Moody’s Investors Service, Inc. (Moody’s), or similarly rated by another NRSRO. We may also invest in unrated bonds, if we believe their credit quality is comparable to those that have investment grade ratings.

The Fund may also invest up to 20% of its net assets in high yield corporate bonds (“junk bonds”). In addition, the Fund may invest up to 35% of its total assets in foreign securities, but the Fund’s total non-U.S.-dollar currency exposure will be limited, in the aggregate, to no more than 25% of net assets.

The average portfolio duration of the Fund will generally vary within two years (plus or minus) of the current average duration of the Barclays Long U.S. Corporate Index, which as of October 31, 2012, was 14 years. Duration measures a bond’s sensitivity to interest rates by indicating the approximate change in a bond or bond fund’s price given a 1% change in interest rates.

Under normal circumstances, the Fund will invest at least 80% of its net assets in corporate bonds. This policy is not a fundamental investment policy and can be changed without shareholder approval. However, shareholders will be given notice at least 60 days prior to any such change.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

Under normal circumstances, the Fund will invest at least 80% of its net assets in corporate bonds.

Risk [Heading]

rr_RiskHeading

What are the principal risks of investing in the Fund?

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

Investing in any mutual fund involves the risk that you may lose part or all of the money you invest. Over time, the value of your investment in the Fund will increase and decrease according to changes in the value of the securities in the Fund’s portfolio. Principal risks include:

Investments not guaranteed by the Manager or its affiliates — Investments in the Fund are not and will not be deposits with or liabilities of Macquarie Bank Limited ABN 46 008 583 542 and its holding companies, including their subsidiaries or related companies (Macquarie Group), and are subject to investment risk, including possible delays in repayment and loss of income and capital invested. No Macquarie Group company guarantees or will guarantee the performance of the Fund, the repayment of capital from the Fund, or any particular rate of return.

Market risk — The risk that all or a majority of the securities in a certain market — such as the stock or bond market — will decline in value because of factors such as adverse political or economic conditions, future expectations, investor confidence, or heavy institutional selling.

Interest rate risk — The risk that securities will decrease in value if interest rates rise. This risk is generally associated with bonds.

Credit risk — The risk that an issuer of a debt security, including a governmental issuer, may be unable to make interest payments and repay principal in a timely manner.

High yield (junk bond) risk — The risk that high yield securities, commonly known as “junk bonds,” are subject to reduced creditworthiness of issuers; increased risk of default and a more limited and less liquid secondary market; and greater price volatility and risk of loss of income and principal than are higher rated securities. High yield bonds are sometimes issued by municipalities with less financial strength and therefore less ability to make projected debt payments on the bonds.

Bank loans and other indebtedness risk — The risk that the portfolio will not receive payment of principal, interest, and other amounts due in connection with these investments and will depend primarily on the financial condition of the borrower and the lending institution.

Foreign risk — The risk that foreign securities (particularly in emerging markets) may be adversely affected by political instability; changes in currency exchange rates; inefficient markets and higher transaction costs; foreign economic conditions; or inadequate or different regulatory and accounting standards.

Forward foreign currency risk — The use of forward foreign currency exchange contracts may substantially change a fund’s exposure to currency exchange rates and could result in losses to the fund if currencies do not perform as the Manager expects. The use of these investments as a hedging technique to reduce a fund’s exposure to currency risks may also reduce its ability to benefit from favorable changes in currency exchange rates.

Liquidity risk — The possibility that securities cannot be readily sold within seven days at approximately the price at which a fund has valued them.

Derivatives risk — Derivative contracts, such as options, futures, and swaps, may involve additional expenses (such as the payment of premiums) and are subject to significant loss if a security, or a securities index to which a derivative contract is associated, moves in the opposite direction from what the portfolio manager anticipated. Derivative contracts are also subject to the risk that the counterparty may fail to perform its obligations under the contract due to financial difficulties (such as a bankruptcy or reorganization).

Government and regulatory risk — The risk that governments or regulatory authorities have, from time to time, taken or considered actions that could adversely affect various sectors of the securities markets.

Risk Lose Money [Text]

rr_RiskLoseMoney

Investing in any mutual fund involves the risk that you may lose part or all of the money you invest. Over time, the value of your investment in the Fund will increase and decrease according to changes in the value of the securities in the Fund’s portfolio.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

Investments in the Fund are not and will not be deposits with or liabilities of Macquarie Bank Limited ABN 46 008 583 542 and its holding companies, including their subsidiaries or related companies (Macquarie Group), and are subject to investment risk, including possible delays in repayment and loss of income and capital invested. No Macquarie Group company guarantees or will guarantee the performance of the Fund, the repayment of capital from the Fund, or any particular rate of return.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

How has Delaware Extended Duration Bond Fund performed?

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year and by showing how the Fund’s average annual returns for the 1-, 5-, and 10-year or lifetime periods compare with those of a broad measure of market performance. The Fund’s past performance (before and after taxes) is not necessarily an indication of how it will perform in the future. The returns reflect expense caps in effect during certain of these periods. The returns would be lower without the expense caps. You may obtain the Fund’s most recently available month-end performance by calling 800 523-1918 or by visiting our website at delawareinvestments.com/performance.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year and by showing how the Fund’s average annual returns for the 1-, 5-, and 10-year or lifetime periods compare with those of a broad measure of market performance.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800 523-1918

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.delawareinvestments.com/performance

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The Fund’s past performance (before and after taxes) is not necessarily an indication of how it will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Year-by-year total return (Class A)*

Bar Chart Does Not Reflect Sales Loads [Text]

rr_BarChartDoesNotReflectSalesLoads

The maximum Class A sales charge of 4.50%, which is normally deducted when you purchase shares, is not reflected in the highest/ lowest quarterly returns or in the bar chart.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

As of September 30, 2012, the Fund’s Class A shares had a calendar year-to-date return of 13.80%. During the periods illustrated in this bar chart, Class A’s highest quarterly return was 14.88% for the quarter ended June 30, 2009 and its lowest quarterly return was -8.61% for the quarter ended September 30, 2008. The maximum Class A sales charge of 4.50%, which is normally deducted when you purchase shares, is not reflected in the highest/ lowest quarterly returns or in the bar chart. If this fee were included, the returns would be less than those shown. The average annual returns in the table below do include the sales charge.

Performance Table Heading

rr_PerformanceTableHeading

Average annual total returns for periods ended December 31, 2011*

Index No Deduction for Fees, Expenses, Taxes [Text]

rr_IndexNoDeductionForFeesExpensesTaxes

reflects no deduction for fees, expenses, or taxes

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

The after-tax returns shown are calculated using the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

After-tax returns are not relevant for shares held in tax-deferred investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs).

Performance Table One Class of after Tax Shown [Text]

rr_PerformanceTableOneClassOfAfterTaxShown

After-tax performance is presented only for Class A shares of the Fund.

Performance Table Footnotes

rr_PerformanceTableFootnotesTextBlock

* Because the Fund has combined its retail and institutional prospectuses, the bar chart and the after tax returns in the average annual total returns table show the performance of the Fund’s Class A shares.

Performance Table Closing [Text Block]

rr_PerformanceTableClosingTextBlock

After-tax performance is presented only for Class A shares of the Fund. The after-tax returns for other Fund classes may vary. Actual after-tax returns depend on the investor’s individual tax situation and may differ from the returns shown. After-tax returns are not relevant for shares held in tax-deferred investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). The after-tax returns shown are calculated using the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact of state and local taxes.

DELAWARE EXTENDED DURATION BOND FUND | Barclays Long U.S. Corporate Index (reflects no deduction for fees, expenses, or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

15.91%

5 years

rr_AverageAnnualReturnYear05

8.51%

10 years or lifetime

rr_AverageAnnualReturnYear10

7.98%

DELAWARE EXTENDED DURATION BOND FUND | CLASS A

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases as a percentage of offering price

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

4.50%

Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Management fees

rr_ManagementFeesOverAssets

0.54%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.30%

Other expenses

rr_OtherExpensesOverAssets

0.22%

Total annual fund operating expenses

rr_ExpensesOverAssets

1.06%

Fee waivers and expense reimbursements

rr_FeeWaiverOrReimbursementOverAssets

(0.11%)

^[1]

Total annual fund operating expenses after fee waivers and expense reimbursements

rr_NetExpensesOverAssets

0.95%

1 year

rr_ExpenseExampleYear01

543

3 years

rr_ExpenseExampleYear03

762

5 years

rr_ExpenseExampleYear05

998

10 years

rr_ExpenseExampleYear10

1,676

Annual Return 2002

rr_AnnualReturn2002

13.02%

Annual Return 2003

rr_AnnualReturn2003

15.04%

Annual Return 2004

rr_AnnualReturn2004

10.03%

Annual Return 2005

rr_AnnualReturn2005

2.85%

Annual Return 2006

rr_AnnualReturn2006

5.33%

Annual Return 2007

rr_AnnualReturn2007

3.02%

Annual Return 2008

rr_AnnualReturn2008

(2.85%)

Annual Return 2009

rr_AnnualReturn2009

24.96%

Annual Return 2010

rr_AnnualReturn2010

14.31%

Annual Return 2011

rr_AnnualReturn2011

16.50%

Year to Date Return, Label

rr_YearToDateReturnLabel

year-to-date return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Sep. 30, 2012

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

13.80%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

highest quarterly return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

14.88%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest quarterly return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(8.61%)

1 year

rr_AverageAnnualReturnYear01

11.22%

5 years

rr_AverageAnnualReturnYear05

9.72%

10 years or lifetime

rr_AverageAnnualReturnYear10

9.44%

DELAWARE EXTENDED DURATION BOND FUND | CLASS A | After Taxes on Distributions

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

8.14%

5 years

rr_AverageAnnualReturnYear05

7.04%

10 years or lifetime

rr_AverageAnnualReturnYear10

6.81%

DELAWARE EXTENDED DURATION BOND FUND | CLASS A | After Taxes on Distributions and sale of Fund shares

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

7.60%

5 years

rr_AverageAnnualReturnYear05

6.76%

10 years or lifetime

rr_AverageAnnualReturnYear10

6.59%

DELAWARE EXTENDED DURATION BOND FUND | CLASS B

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases as a percentage of offering price

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower

rr_MaximumDeferredSalesChargeOverOfferingPrice

4.00%

^[2]

Management fees

rr_ManagementFeesOverAssets

0.54%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

0.22%

Total annual fund operating expenses

rr_ExpensesOverAssets

1.76%

Fee waivers and expense reimbursements

rr_FeeWaiverOrReimbursementOverAssets

(0.06%)

^[1]

Total annual fund operating expenses after fee waivers and expense reimbursements

rr_NetExpensesOverAssets

1.70%

1 year

rr_ExpenseExampleYear01

573

3 years

rr_ExpenseExampleYear03

773

5 years

rr_ExpenseExampleYear05

1,099

10 years

rr_ExpenseExampleYear10

1,883

1 year

rr_ExpenseExampleNoRedemptionYear01

173

3 years

rr_ExpenseExampleNoRedemptionYear03

548

5 years

rr_ExpenseExampleNoRedemptionYear05

949

10 years

rr_ExpenseExampleNoRedemptionYear10

1,883

1 year

rr_AverageAnnualReturnYear01

11.66%

5 years

rr_AverageAnnualReturnYear05

9.68%

10 years or lifetime

rr_AverageAnnualReturnYear10

9.27%

DELAWARE EXTENDED DURATION BOND FUND | CLASS C

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases as a percentage of offering price

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower

rr_MaximumDeferredSalesChargeOverOfferingPrice

1.00%

^[2]

Management fees

rr_ManagementFeesOverAssets

0.54%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

0.22%

Total annual fund operating expenses

rr_ExpensesOverAssets

1.76%

Fee waivers and expense reimbursements

rr_FeeWaiverOrReimbursementOverAssets

(0.06%)

^[1]

Total annual fund operating expenses after fee waivers and expense reimbursements

rr_NetExpensesOverAssets

1.70%

1 year

rr_ExpenseExampleYear01

273

3 years

rr_ExpenseExampleYear03

548

5 years

rr_ExpenseExampleYear05

949

10 years

rr_ExpenseExampleYear10

2,068

1 year

rr_ExpenseExampleNoRedemptionYear01

173

3 years

rr_ExpenseExampleNoRedemptionYear03

548

5 years

rr_ExpenseExampleNoRedemptionYear05

949

10 years

rr_ExpenseExampleNoRedemptionYear10

2,068

1 year

rr_AverageAnnualReturnYear01

14.64%

5 years

rr_AverageAnnualReturnYear05

9.92%

10 years or lifetime

rr_AverageAnnualReturnYear10

9.13%

DELAWARE EXTENDED DURATION BOND FUND | CLASS R

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases as a percentage of offering price

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Management fees

rr_ManagementFeesOverAssets

0.54%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.60%

Other expenses

rr_OtherExpensesOverAssets

0.22%

Total annual fund operating expenses

rr_ExpensesOverAssets

1.36%

Fee waivers and expense reimbursements

rr_FeeWaiverOrReimbursementOverAssets

(0.16%)

^[1]

Total annual fund operating expenses after fee waivers and expense reimbursements

rr_NetExpensesOverAssets

1.20%

1 year

rr_ExpenseExampleYear01

122

3 years

rr_ExpenseExampleYear03

415

5 years

rr_ExpenseExampleYear05

729

10 years

rr_ExpenseExampleYear10

1,621

Label

rr_AverageAnnualReturnLabel

(lifetime: 10/3/05-12/31/11)

1 year

rr_AverageAnnualReturnYear01

16.20%

5 years

rr_AverageAnnualReturnYear05

10.45%

lifetime

rr_AverageAnnualReturnSinceInception

9.15%

Inception Date

rr_AverageAnnualReturnInceptionDate

Oct. 03, 2005

DELAWARE EXTENDED DURATION BOND FUND | INSTITUTIONAL CLASS

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases as a percentage of offering price

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum contingent deferred sales charge (load) as a percentage of original purchase price or redemption price, whichever is lower

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Management fees

rr_ManagementFeesOverAssets

0.54%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.22%

Total annual fund operating expenses

rr_ExpensesOverAssets

0.76%

Fee waivers and expense reimbursements

rr_FeeWaiverOrReimbursementOverAssets

(0.06%)

^[1]

Total annual fund operating expenses after fee waivers and expense reimbursements

rr_NetExpensesOverAssets

0.70%

1 year

rr_ExpenseExampleYear01

72

3 years

rr_ExpenseExampleYear03

237

5 years

rr_ExpenseExampleYear05

416

10 years

rr_ExpenseExampleYear10

937

Label

rr_AverageAnnualReturnLabel

INSTITUTIONAL CLASS return before taxes

1 year

rr_AverageAnnualReturnYear01

16.81%

5 years

rr_AverageAnnualReturnYear05

10.99%

10 years or lifetime

rr_AverageAnnualReturnYear10

10.21%

[1] The Fund’s investment manager, Delaware Management Company (Manager), is contractually waiving its investment advisory fees and/or paying expenses (excluding any 12b-1 fees, taxes, interest, inverse floater program expenses, short sale and dividend interest expenses, brokerage fees, certain insurance costs, and nonroutine expenses or costs, including, but not limited to, those relating to reorganizations, litigation, conducting shareholder meetings, and liquidations) to the extent necessary to prevent total annual fund operating expenses from exceeding 0.70% of the Fund’s average daily net assets from November 28, 2012 through November 28, 2013. The Fund’s distributor, Delaware Distributors, L.P. (Distributor), has also contracted to limit the Class A and Class R shares’ 12b-1 fees from November 28, 2012 through November 28, 2013 to no more than 0.25% and 0.50% of their respective average daily net assets. These waivers and reimbursements may only be terminated by agreement of the Manager and the Distributor, as applicable, and the Fund.

[2] If you redeem Class B shares during the first year after you buy them, you will pay a contingent deferred sales charge (CDSC) of 4.00%, which declines to 3.00% during the second year, 2.25% during the third year, 1.50% during the fourth and fifth years, 1.00% during the sixth year, and 0% thereafter. Class C shares redeemed within one year of purchase are subject to a 1.00% CDSC.

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DELAWARE EXTENDED DURATION BOND FUND

Delaware Extended Duration Bond Fund

What is the Fund’s investment objective?

Delaware Extended Duration Bond Fund seeks to provide investors with total return.

What are the Fund’s fees and expenses?

The following table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales-charge discounts if you and your family invest, or agree to invest in the future, at least $100,000 in Delaware Investments^® Funds. More information about these and other discounts is available from your financial advisor, in the Fund’s prospectus under the section entitled “About your account,” and in the Fund’s statement of additional information under the section entitled “Purchasing shares.”

Shareholder fees (fees paid directly from your investment)

Shareholder Fees DELAWARE EXTENDED DURATION BOND FUND	CLASS A	CLASS B		CLASS C		CLASS R	INSTITUTIONAL CLASS
Maximum sales charge (load) imposed on purchases as a percentage of offering price	4.50%	none		none		none	none
Maximum contingent deferred sales charge (load) as a percentage of original percentage price or redemption price, whichever is lower	none	4.00%	[1]	1.00%	[1]	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 DELAWARE EXTENDED DURATION BOND FUND		CLASS A	CLASS B	CLASS C	CLASS R	INSTITUTIONAL CLASS
Management fees		0.54%	0.54%	0.54%	0.54%	0.54%
Distribution and service (12b-1) fees		0.30%	1.00%	1.00%	0.60%	none
Other expenses		0.22%	0.22%	0.22%	0.22%	0.22%
Total annual fund operating expenses		1.06%	1.76%	1.76%	1.36%	0.76%
Fee waivers and expense reimbursements	[1]	(0.11%)	(0.06%)	(0.06%)	(0.16%)	(0.06%)
Total annual fund operating expenses after fee waivers and expense reimbursements		0.95%	1.70%	1.70%	1.20%	0.70%

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 in the Fund 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 reflects the applicable waivers and reimbursements for the 1-year contractual period and the total operating expenses without waivers for years 2 through 10. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example DELAWARE EXTENDED DURATION BOND FUND (USD $)	1 year	3 years	5 years	10 years
CLASS A	543	762	998	1,676
CLASS B	573	773	1,099	1,883
CLASS C	273	548	949	2,068
CLASS R	122	415	729	1,621
INSTITUTIONAL CLASS	72	237	416	937

if not redeemed

Expense Example, No Redemption DELAWARE EXTENDED DURATION BOND FUND (USD $)	1 year	3 years	5 years	10 years
CLASS B	173	548	949	1,883
CLASS C	173	548	949	2,068

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 172% of the average value of its portfolio.

What are the Fund’s principal investment strategies?

The Fund invests primarily in corporate bonds. Our focus is on corporate bonds that have investment grade credit ratings from a nationally recognized statistical rating organization (NRSRO). The bonds we select for the portfolio are typically rated BBB- and above by Standard & Poor’s (S&P), Baa3 and above by Moody’s Investors Service, Inc. (Moody’s), or similarly rated by another NRSRO. We may also invest in unrated bonds, if we believe their credit quality is comparable to those that have investment grade ratings.

The Fund may also invest up to 20% of its net assets in high yield corporate bonds (“junk bonds”). In addition, the Fund may invest up to 35% of its total assets in foreign securities, but the Fund’s total non-U.S.-dollar currency exposure will be limited, in the aggregate, to no more than 25% of net assets.

The average portfolio duration of the Fund will generally vary within two years (plus or minus) of the current average duration of the Barclays Long U.S. Corporate Index, which as of October 31, 2012, was 14 years. Duration measures a bond’s sensitivity to interest rates by indicating the approximate change in a bond or bond fund’s price given a 1% change in interest rates.

Under normal circumstances, the Fund will invest at least 80% of its net assets in corporate bonds. This policy is not a fundamental investment policy and can be changed without shareholder approval. However, shareholders will be given notice at least 60 days prior to any such change.

What are the principal risks of investing in the Fund?

Investing in any mutual fund involves the risk that you may lose part or all of the money you invest. Over time, the value of your investment in the Fund will increase and decrease according to changes in the value of the securities in the Fund’s portfolio. Principal risks include:

Investments not guaranteed by the Manager or its affiliates — Investments in the Fund are not and will not be deposits with or liabilities of Macquarie Bank Limited ABN 46 008 583 542 and its holding companies, including their subsidiaries or related companies (Macquarie Group), and are subject to investment risk, including possible delays in repayment and loss of income and capital invested. No Macquarie Group company guarantees or will guarantee the performance of the Fund, the repayment of capital from the Fund, or any particular rate of return.

Market risk — The risk that all or a majority of the securities in a certain market — such as the stock or bond market — will decline in value because of factors such as adverse political or economic conditions, future expectations, investor confidence, or heavy institutional selling.

Interest rate risk — The risk that securities will decrease in value if interest rates rise. This risk is generally associated with bonds.

Credit risk — The risk that an issuer of a debt security, including a governmental issuer, may be unable to make interest payments and repay principal in a timely manner.

High yield (junk bond) risk — The risk that high yield securities, commonly known as “junk bonds,” are subject to reduced creditworthiness of issuers; increased risk of default and a more limited and less liquid secondary market; and greater price volatility and risk of loss of income and principal than are higher rated securities. High yield bonds are sometimes issued by municipalities with less financial strength and therefore less ability to make projected debt payments on the bonds.

Bank loans and other indebtedness risk — The risk that the portfolio will not receive payment of principal, interest, and other amounts due in connection with these investments and will depend primarily on the financial condition of the borrower and the lending institution.

Foreign risk — The risk that foreign securities (particularly in emerging markets) may be adversely affected by political instability; changes in currency exchange rates; inefficient markets and higher transaction costs; foreign economic conditions; or inadequate or different regulatory and accounting standards.

Forward foreign currency risk — The use of forward foreign currency exchange contracts may substantially change a fund’s exposure to currency exchange rates and could result in losses to the fund if currencies do not perform as the Manager expects. The use of these investments as a hedging technique to reduce a fund’s exposure to currency risks may also reduce its ability to benefit from favorable changes in currency exchange rates.

Liquidity risk — The possibility that securities cannot be readily sold within seven days at approximately the price at which a fund has valued them.

Derivatives risk — Derivative contracts, such as options, futures, and swaps, may involve additional expenses (such as the payment of premiums) and are subject to significant loss if a security, or a securities index to which a derivative contract is associated, moves in the opposite direction from what the portfolio manager anticipated. Derivative contracts are also subject to the risk that the counterparty may fail to perform its obligations under the contract due to financial difficulties (such as a bankruptcy or reorganization).

Government and regulatory risk — The risk that governments or regulatory authorities have, from time to time, taken or considered actions that could adversely affect various sectors of the securities markets.

How has Delaware Extended Duration Bond Fund performed?

The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year and by showing how the Fund’s average annual returns for the 1-, 5-, and 10-year or lifetime periods compare with those of a broad measure of market performance. The Fund’s past performance (before and after taxes) is not necessarily an indication of how it will perform in the future. The returns reflect expense caps in effect during certain of these periods. The returns would be lower without the expense caps. You may obtain the Fund’s most recently available month-end performance by calling 800 523-1918 or by visiting our website at delawareinvestments.com/performance.

Year-by-year total return (Class A)*

As of September 30, 2012, the Fund’s Class A shares had a calendar year-to-date return of 13.80%. During the periods illustrated in this bar chart, Class A’s highest quarterly return was 14.88% for the quarter ended June 30, 2009 and its lowest quarterly return was -8.61% for the quarter ended September 30, 2008. The maximum Class A sales charge of 4.50%, which is normally deducted when you purchase shares, is not reflected in the highest/ lowest quarterly returns or in the bar chart. If this fee were included, the returns would be less than those shown. The average annual returns in the table below do include the sales charge.

Average annual total returns for periods ended December 31, 2011*

Average Annual Total Returns DELAWARE EXTENDED DURATION BOND FUND	Label	1 year	5 years	10 years or lifetime	lifetime	Inception Date
CLASS A		11.22%	9.72%	9.44%
CLASS A After Taxes on Distributions		8.14%	7.04%	6.81%
CLASS A After Taxes on Distributions and sale of Fund shares		7.60%	6.76%	6.59%
CLASS B		11.66%	9.68%	9.27%
CLASS C		14.64%	9.92%	9.13%
CLASS R	(lifetime: 10/3/05-12/31/11)	16.20%	10.45%		9.15%	Oct. 03, 2005
INSTITUTIONAL CLASS	INSTITUTIONAL CLASS return before taxes	16.81%	10.99%	10.21%
Barclays Long U.S. Corporate Index (reflects no deduction for fees, expenses, or taxes)		15.91%	8.51%	7.98%

* Because the Fund has combined its retail and institutional prospectuses, the bar chart and the after tax returns in the average annual total returns table show the performance of the Fund’s Class A shares.

After-tax performance is presented only for Class A shares of the Fund. The after-tax returns for other Fund classes may vary. Actual after-tax returns depend on the investor’s individual tax situation and may differ from the returns shown. After-tax returns are not relevant for shares held in tax-deferred investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). The after-tax returns shown are calculated using the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact of state and local taxes.

[1] If you redeem Class B shares during the first year after you buy them, you will pay a contingent deferred sales charge (CDSC) of 4.00%, which declines to 3.00% during the second year, 2.25% during the third year, 1.50% during the fourth and fifth years, 1.00% during the sixth year, and 0% thereafter. Class C shares redeemed within one year of purchase are subject to a 1.00% CDSC.

[1] The Fund’s investment manager, Delaware Management Company (Manager), is contractually waiving its investment advisory fees and/or paying expenses (excluding any 12b-1 fees, taxes, interest, inverse floater program expenses, short sale and dividend interest expenses, brokerage fees, certain insurance costs, and nonroutine expenses or costs, including, but not limited to, those relating to reorganizations, litigation, conducting shareholder meetings, and liquidations) to the extent necessary to prevent total annual fund operating expenses from exceeding 0.70% of the Fund’s average daily net assets from November 28, 2012 through November 28, 2013. The Fund’s distributor, Delaware Distributors, L.P. (Distributor), has also contracted to limit the Class A and Class R shares’ 12b-1 fees from November 28, 2012 through November 28, 2013 to no more than 0.25% and 0.50% of their respective average daily net assets. These waivers and reimbursements may only be terminated by agreement of the Manager and the Distributor, as applicable, and the Fund.