INVESTMENT OBJECTIVE

The Fund seeks to maximize income, to the extent consistent with preservation of capital, primarily through investment in debt securities issued or guaranteed by the U.S. government, its agencies or instrumentalities. This objective may be changed by the Fund’s Board of Trustees without shareholder approval.

FEES AND EXPENSES OF THE FUND

This 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 $50,000 in Calvert mutual funds that are not money market funds. More information about these and other discounts is available from your financial professional and under “Choosing a Share Class” on page 48 and “Reduced Sales Charges” on page 52 of the Fund’s Prospectus, and under “Method of Distribution” on page 49 of the Fund’s Statement of Additional Information.

Shareholder Fees (fees paid directly from your investment)
	Class A		Class C
Maximum sales charge (load) on pur-	3.75	%	None
chases (as a % of offering price)
Maximum deferred sales charge (load)	None		1.00	%
(as a % of amount purchased or
redeemed, whichever is lower) 1
Redemption fee (as a % of amount	2.00	%	2.00	%
redeemed or exchanged within 30
days of purchase)
Annual Fund Operating Expenses (expenses that you pay each year as a
% of the value of your investment)
	Class A		Class C
Management fees	0.55	%	0.55	%
Distribution and service (12b-1) fees	0.25	%	1.00	%
Other expenses	0.57	%	0.65	%
Total annual fund operating expenses	1.37	%	2.20	%
Less fee waiver and/or expense reim-	(0.33	%)	(0.16	%)
bursement 2
Net expenses	1.04	%	2.04	%

1 The contingent deferred sales charge reduces over time.

2 The investment advisor has agreed to contractually limit direct net annual fund operating expenses for Class A and Class C through January 31, 2014.

Direct net operating expenses will not exceed 1.04% for Class A and 2.04% for Class C. Calvert has further agreed to contractually limit direct net annual fund operating expenses for Class C to 5.00% through January 31, 2023. Only the Board of Trustees of the Fund may terminate the Fund’s expense limitation before the contractual period expires.

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 either redeem or hold your shares at the end of those periods;
• your investment has a 5% return each year;
• the Fund’s operating expenses remain the same; and
• any Calvert expense limitation is in effect for the period indicated in the fee table above.

Although your actual costs may be higher or lower, under these assumptions your costs would be:

Share Class	1 Year	3 Years	5 Years	10 Years
Class A	$477	$761	$1,067	$1,932
Class C
Expenses assuming	$307	$673	$1,165	$2,521
redemption
Expenses assuming
no redemption	$207	$673	$1,165	$2,521

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (“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 311% of its portfolio’s average value.

SUMMARY PROSPECTUS JANUARY 31, 2013 1

INVESTMENTS, RISKS AND PERFORMANCE

Principal Investment Strategies

Under normal circumstances, the Fund will invest at least 80% of its net assets (including borrowings for investment purposes) in (i) debt securities issued or guaranteed by the U.S. government, its agencies or instrumentalities (“U.S. Government Securities”), (ii) repurchase agreements collateralized by U.S. Government Securities and (iii) incidental to those investments, futures contracts that are related to U.S. Government Securities. The Fund will provide shareholders with at least 60 days’ notice before changing this 80% policy.

The Fund uses an active strategy, seeking relative value to earn incremental income. The investment advisor allocates the Fund’s assets among different market sectors (e.g., U.S. Treasury or U.S. government agency) and different maturities based on its view of the relative value of each sector or maturity. There is no limit on the Fund’s average maturity.

The Fund also may invest in corporate debt securities, trust preferred securities, taxable municipal securities, asset-backed securities (“ABS”), including commercial mortgage-backed securities, and repurchase agreements.

The Fund may invest in securities that represent interests in pools of mortgage loans or other assets assembled for sale to investors by various U.S. governmental agencies, government-related organizations and private issuers. These investments may include derivative securities such as collateralized mortgage obligations (“CMOs”) and ABS.

In addition, the Fund may invest in leveraged loans. The loans in which the Fund will invest are expected to be below-investment-grade quality and to bear interest at a floating rate that resets periodically.

The Fund is “non-diversified,” which means it may invest a greater percentage of its assets in a particular issuer than a “diversified” fund.

The Fund uses a hedging technique that includes the purchase and sale of U.S. Treasury securities and related futures contracts to manage the duration of the Fund.

Tobacco Exclusion. The Fund seeks to avoid investing in companies classified under the tobacco industry sector of the Barclays Global Aggregate Index, the Barclays U.S. High Yield Index or the Barclays Global Emerging Market Index; or, in the opinion of the Fund’s Advisor, any similar securities in the Barclays Municipal Index.

Principal Risks

You could lose money on your investment in the Fund, or the Fund could underperform, because of the risks described below. An investment in the Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Non-Diversification Risk. Because the Fund may invest a greater percentage of its assets in a particular issuer than a diversified fund, the gains or losses on a single bond may have greater impact on the Fund than a diversified fund.

Bond Market Risk. The market prices of bonds held by the Fund may fall.

Credit Risk. The credit quality of fixed-income securities may deteriorate, which could lead to default or bankruptcy of the issuer where the issuer becomes unable to pay its obligations when due.

Mortgage-Backed and Asset-Backed Securities Risk. The value of investments in mortgage-backed and asset-backed securities is subject to interest rate risk and credit risk. These securities are also subject to the risk that borrowers will prepay the principal on their loans more quickly than expected (prepayment risk) or more slowly than expected (extension risk), which will affect the yield, average life and price of the securities. In addition, faster than expected prepayments may cause the Fund to invest the prepaid principal in lower yielding securities and slower than expected prepayments may reduce the potential for the Fund to invest in higher yielding securities.

Mortgage-Backed Security Risk (Government-Sponsored Enterprises).  Debt and mortgage-backed securities issued by government-sponsored enterprises (“GSEs”) such as the Federal National Mortgage Association (“FNMA”) and the Federal Home Loan Mortgage Corporation (“FHLMC”) are neither insured nor guaranteed by the U.S. Treasury and are not backed by the full faith and credit of the U.S. government. Such securities are only supported by the credit of the applicable GSE. The U.S. government has provided financial support to FNMA and FHLMC, but there can be no assurance that it will support these or other GSEs in the future.

Leveraged Loan Risk. Leveraged loans are subject to the risks typically associated with debt securities, such as credit risk discussed above. In addition, leveraged loans, which typically hold a senior position in the capital structure of a borrower, are subject to the risk that a court could subordinate such loans to presently existing or future indebtedness or take other action detrimental to the holders of leveraged loans. Leveraged loans are also subject to the risk that the value of the collateral, if any, securing a loan may decline, be insufficient to meet the obligations of the borrower, or be difficult to liquidate. Some leveraged loans are not as easily purchased or sold as publicly-traded securities and others are illiquid, which may make it more difficult for the Fund to value them or dispose of them at an acceptable price. Leveraged loans are usually more credit sensitive than investment-grade securities.

Management Risk. The individual investments of the Fund may not perform as expected, due to credit, political or other risks and/or the Fund’s portfolio management practices may not achieve the desired result.

Interest Rate Risk. A change in interest rates may adversely affect the value of fixed-income securities. When interest rates rise, the value of fixed-income securities will generally fall. Longer-term securities are subject to greater interest rate risk.

Unrated Security Risk. Unrated securities may be less liquid than rated securities determined to be of comparable quality. When the Fund purchases unrated securities, it will depend on the Advisor’s analysis of credit risk without the assessment of a nationally recognized statistical rating organization.

Corporate and Taxable Municipal Bond Risk. For corporate and taxable municipal bonds, there is credit risk in addition to the interest rate risk that affects all fixed-income securities.

Trust Preferred Securities Risk. Trust preferred securities are preferred stocks issued by a special purpose trust subsidiary backed by subordinated debt of the corporate parent. Trust preferred securities are subject to unique risks, which include the fact that dividend payments

SUMMARY PROSPECTUS JANUARY 31, 2013 2

will only be paid if interest payments on the underlying obligations are made, which interest payments are dependent on the financial condition of the parent corporation. There is also the risk that the underlying obligations, and thus the trust preferred securities, may be prepaid after a stated call date or as a result of certain tax or regulatory events, resulting in a lower yield to maturity.

Collateralized Mortgage Obligation and Structured Asset-Backed Securities Risk. A CMO is a multiclass bond that is backed by a pool of mortgage loans or mortgage-backed securities. A structured ABS is a multiclass bond that is typically backed by a pool of auto loans, credit card receivables, home equity loans or student loans. A CMO or structured ABS is subject to interest rate risk, credit risk, prepayment risk and extension risk. In addition, if the Fund holds a class of a CMO or a structured ABS that is subordinated to other classes backed by the same pool of collateral, the likelihood that the Fund will receive payments of principal may be substantially limited.

Repurchase Agreement Risk. A repurchase agreement exposes the Fund to the risk that the party that sells the security may default on its obligation to repurchase it. The Fund may lose money because it cannot sell the security at the agreed-upon time and price or the security loses value before it can be sold.

Active Trading Strategy Risk. The Fund employs an active style that seeks to position the Fund with securities that offer the greatest price appreciation while minimizing risk. This style can result in higher turnover (exceeding 100%), may translate to higher transaction costs and may increase your tax liability.

Futures Contracts Risk. The value of a futures contract tends to increase and decrease in tandem with the value of the underlying instrument. The price of futures can be highly volatile; using them could lower total return, and the potential loss from futures can exceed the Fund’s initial investment in such contracts.

Performance

The following bar chart and table show the Fund’s annual returns and its long-term performance, which give some indication of the risks of investing in the Fund. The bar chart shows how the performance of the Class A shares has varied from year to year. The table compares the Fund’s performance over time with that of an index and an average.

The Fund’s past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. For updated performance information, visit www.calvert.com.

The return for each of the Fund’s other Classes of shares will differ from the Class A returns shown in the bar chart, depending upon the expenses of that Class. The bar chart does not reflect any sales charge that you may be required to pay upon purchase or redemption of the Fund’s shares. Any sales charge will reduce your return.

Calendar Year Total Returns for Class A at NAV

	Quarter Ended	Total Return
Best Quarter (of periods shown)	9/30/09	4.42	%
Worst Quarter (of periods shown)	6/30/09	-0.88	%

The average total return table shows the Fund’s returns with the maximum sales charge deducted, and no sales charge has been applied to the indices used for comparison in the table.

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on your tax situation and may differ from those shown. The after-tax returns shown are not relevant to you if you hold your Fund shares through a tax-deferred arrangement such as a 401(k) plan or individual retirement account. The return after taxes on distributions and sale of Fund shares may be higher than the return before taxes because the calculation assumes that shareholders receive a tax benefit for capital losses incurred on the sale of their shares. After-tax returns are shown only for Class A shares; after-tax returns for other Classes will vary.

Average Annual Total Returns
(as of 12-31-12) (with maximum			Since Inception
sales charge deducted)	1 Year		(12/31/08	)
Class A:
Return before taxes	-1.64	%	5.21	%
Return after taxes on	-2.69	%	4.12	%
distributions
Return after taxes on	-0.95	%	3.86	%
distributions and sale
of Fund shares
Class C:	0.15	%	5.19	%
Barclays U.S. Government Index	2.02	%	3.51	%
(reflects no deduction for fees,
expenses or taxes)
Lipper General U.S. Government	2.39	%	4.74	%
Funds Avg.
(reflects no deduction for taxes)

SUMMARY PROSPECTUS JANUARY 31, 2013 3

PORTFOLIO MANAGEMENT

Investment Advisor. Calvert Investment Management, Inc. (“Calvert” or the “Advisor”)

Portfolio		Length of Time
Manager Name	Title	Managing Fund
Matthew Duch	Vice President, Portfolio	Since September 2011
	Manager
Michael Abramo	Vice President, Portfolio	Since September 2011
	Manager
Vishal Khanduja,	Portfolio Manager	Since July 2012
CFA

BUYING AND SELLING SHARES

You can buy, sell (redeem) or exchange shares of the Fund either through a financial professional or directly from the Fund, on any day that the New York Stock Exchange is open. The share price is based on the Fund’s net asset value determined after receipt of your request in good order.

Minimum Investments
Account Type	Initial	Subsequent
Regular Accounts	$2,000	$250
IRA Accounts	$1,000	$250

For automatic investment plans, the minimum initial investment requirements are waived if you establish a $100 monthly investment plan. For an account that has met the minimum initial investment requirement described above, you may make subsequent automatic investments of $50.

The Fund may waive investment minimums and applicable service fees for certain investors.

Class A and C Shares. To buy shares, contact your financial professional or open an account by completing and signing an application (available at www.calvert.com or by calling 800-368-2748). Make your check payable to the Fund.

To Buy Shares
New Accounts (include	Calvert, P.O. Box 219544,
application):	Kansas City, MO 64121-9544
Subsequent Investments	Calvert, P.O. Box 219739,
(include investment slip):	Kansas City, MO 64121-9739
By Registered, Certified or	Calvert, c/o BFDS,
Overnight Mail:	330 West 9th Street,
	Kansas City, MO 64105-1514
To Sell Shares
By Telephone	Call 800-368-2745
By Mail	Calvert, P.O. Box 219544, Kansas City,
	MO 64121-9544

TAX INFORMATION

Unless you are investing through a tax-deferred arrangement, such as a 401(k) plan or an individual retirement account, any dividends and distributions made by the Fund are taxable to you as ordinary income or capital gains and may also be subject to state and local taxes.

PAYMENTS TO BROKER/DEALERS AND OTHER FINANCIAL INTERMEDIARIES

If you purchase shares of the Fund through a broker/dealer or other financial intermediary (such as a bank), the Fund and 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 Web site for more information.

Investment Company Act file:

No. 811- 3416 The Calvert Fund

SUMMARY PROSPECTUS JANUARY 31, 2013 4