⁽¹⁾ For the period from the start of business, March 1, 2002, to October 31, 2002.

⁽³⁾ The investment adviser waived a portion of its investment advisory fee (equal to less than 0.01% of average daily net assets for each of the years ended October 31, 2006, 2005, and 2004). A portion of the waiver was borne by the sub-adviser.

Tax-Managed Mid-Cap Core Portfolio (the Portfolio) is registered under the Investment Company Act of 1940, as amended, as a diversified open-end management investment company. The Portfolio, which was organized as a trust under the laws of the State of New York on December 10, 2001, seeks to achieve long-term, after-tax returns by investing in a diversified portfolio of common stocks of mid-cap companies. The Declaration of Trust permits the Trustees to issue interests in the Portfolio. At October 31, 2006, the Eaton Vance Tax-Managed Mid-Cap Core Fund and the Eaton Vance Tax-Managed Equity Asset Allocation Fund held 32.1% and 67.9% interests in the Portfolio, respectively. The following is a summary of significant accounting policies consistently followed by the Portfolio in the preparation of its financial statements. The policies are in conformity with accounting principles generally accepted in the United States of America.

A Investment Valuation — Securities listed on a U.S. securities exchange generally are valued at the last sale price on the day of valuation or, if no sales took place on such date, at the mean between the closing bid and asked prices therefore on the exchange where such securities are principally traded. Equity securities listed on the NASDAQ National Market System generally are valued at the official NASDAQ closing price. Unlisted or listed securities for which closing sales prices or closing quotations are not available are valued at the mean between the latest available bid and asked prices, or, in the case of preferred equity securities that are not listed or traded in the over-the-counter market, by an independent pricing service. Exchange-traded options are valued at the last sale price for the day of valuation as quoted on the principal exchange or board of trade on which the options are traded or, in the absence of sales on such date, at the mean between the latest bid and asked prices therefore. Futures positions on securities and currencies generally are valued at closing settlement prices. Short-term debt securities with a remaining maturity of 60 days or less are valued at amortized cost. If short-term debt securities are acquired with a remaining maturity of more than 60 days, they will be valued by a pricing service. Other fixed income and debt securities, including listed securities and securities for which price quotations are available, will normally be valued on the basis of valuations furnished by a pricing service. Foreign securities and currencies are valued in U.S. dollars, based on foreign currency exchange rate quotations supplied by an independent quotation service. The daily valuation of exchange-traded foreign securities generally is determined as of the close of trading on the principal exchange on which such securities trade. Events occurring after the close of trading on foreign exchanges may result in adjustments to the valuation of foreign securities to more accurately reflect their fair value as of the close of regular trading on the New York Stock Exchange. When valuing foreign securities that meet certain criteria, the Trustees have approved the use of a fair value service that values such securities to reflect market trading that occurs after the close of the applicable foreign markets of comparable securities or other instruments that have a strong correlation to the fair-valued securities. Investments held by the Portfolio for which valuations or market quotations are unavailable are valued at fair value using methods determined in good faith by or at the direction of the Trustees of the Portfolio considering relevant factors, data and information including the market value of freely tradable securities of the same class in the principal market on which such securities are normally traded.

B Income — Dividend income is recorded on the ex-dividend date for dividends received in cash and/or securities. However, if the ex-dividend date has passed, certain dividends from foreign securities are recorded as the Portfolio is informed of the ex-dividend date. Withholding taxes on foreign dividends and capital gains have been provided for in accordance with the Portfolio's understanding of the applicable countries' tax rules and rates. Interest income is recorded on the accrual basis.

C Federal Taxes — The Portfolio has elected to be treated as a partnership for federal tax purposes. No provision is made by the Portfolio for federal or state taxes on any taxable income of the Portfolio because each investor in the Portfolio is ultimately responsible for the payment of any taxes on its share of taxable income. Since at least one of the Portfolio's investors is a regulated investment company that invests all or substantially all of its assets in the Portfolio, the Portfolio normally must satisfy the applicable source of income and diversification requirements (under the Internal Revenue Code) in order for its investors to satisfy them. The Portfolio will allocate, at least annually among its investors, each investor's distributive share of the Portfolio's net investment income, net realized capital gains, and any other items of income, gain, loss, deduction or credit.

D Expense Reduction — Investors Bank & Trust Company (IBT) serves as custodian of the Portfolio. Pursuant to the custodian agreement, IBT receives a fee reduced by credits which are determined based on the average daily cash balance the Portfolio maintains with IBT. All credit balances used to reduce the Portfolio's custodian fees are reported as a reduction of expenses in the Statement of Operations.

E Financial Futures Contract — Upon entering a financial futures contract, the Portfolio is required to deposit either in cash or securities an amount (initial margin) equal to a certain percentage of the purchase price indicated in the financial futures contract. Subsequent payments are made or received by the Portfolio (margin maintenance) each day, dependent on daily fluctuations in the value of the underlying security, and are recorded for book purposes as unrealized gains or losses by the Portfolio. The Portfolio's investment in financial futures contracts is designed to hedge against anticipated future changes in price of current or anticipated Portfolio positions. Should prices move unexpectedly, the Portfolio may not achieve the anticipated benefits of the financial futures contracts and may realize a loss.

F Purchased Options — Upon the purchase of a call or put option, the premium paid by the Portfolio is included in the Statement of Assets and Liabilities as an investment. The amount of the investment is subsequently marked-to-market to reflect the current market value of the option purchased, in accordance with the Portfolio's policies on investment valuations discussed above. If an option which the Portfolio has purchased expires on the stipulated expiration date, the Portfolio will realize a loss in the amount of the cost of the option. If the Portfolio enters into a closing sale transaction, the Portfolio will realize a gain or loss, depending on whether the sales proceeds from the closing sale transaction are greater or less than the cost of the option. If a Portfolio exercises a put option, it will realize a gain or loss from the sale of the underlying security, and the proceeds from such sale will be decreased by the premium originally paid. If the Portfolio exercises a call option, the cost of the security which the Portfolio purchases upon exercise will be increased by the premium originally paid.

G Securities Sold Short — The Portfolio may sell individual securities short if it owns at least an equal amount of the security sold short or has at the time of sale a right to obtain securities equivalent in kind and amount to the securities sold and provided that, if such right is conditional, the sale is made upon the same conditions (a covered short sale). The Portfolio may sell short securities representing an index or basket of securities whose constituents the Portfolio holds in whole or in part. A short sale of an index or basket security will be a covered short sale if the underlying index or basket of securities is the same or substantially identical to securities held by the Portfolio.

The seller of a short position generally realizes a profit on the transaction if the price it receives on the short sale exceeds the cost of closing out the position by purchasing securities in the market, but generally realizes a loss if the cost of closing out the short position exceeds the proceeds of the short sale. The exposure to loss on covered short sales (to the extent the value of the security sold short rises instead of falls) is offset by the increase in the value of the underlying security or securities retained. The profit or loss on a covered short sale is also affected by the borrowing cost of any securities borrowed in connection with the short sale (which will vary with market conditions) and use of the proceeds of the short sale. The Portfolio expects normally to close its covered short sales by delivering newly-acquired stock.

Exposure to loss on an index or basket security sold short will not be offset by gains on other securities holdings to the extent that the constituent securities of the index or basket security sold short are not held by the Portfolio. Such losses may be substantial.

H Foreign Currency Translation — Investment valuations, other assets, and liabilities initially expressed in foreign currencies are converted each business day into U.S. dollars based upon current exchange rates. Purchases and sales of foreign investment securities and income and expenses are converted into U.S. dollars based upon currency exchange rates prevailing on the respective dates of such transactions. Recognized gains or losses on investment transactions attributable to changes in foreign currency exchange rates are recorded for financial statement purposes as net realized gains and losses on investments. That portion of unrealized gains and losses on investments that results from fluctuations in foreign currency exchange rates is not separately disclosed.

I Use of Estimates — The preparation of the financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of income and expense during the reporting period. Actual results could differ from those estimates.

J Other — Investment transactions are accounted for on the date the securities are purchased or sold. Realized gains and losses on securities sold are determined on the basis of identified cost.

K Indemnifications — Under the Portfolio's organizational documents, its officers and Trustees may be indemnified against certain liabilities and expenses arising

out of the performance of their duties to the Portfolio. Interestholders in the Portfolio are jointly and severally liable for the liabilities and obligations of the Portfolio in the event that the Portfolio fails to satisfy such liabilities and obligations; provided, however, that, to the extent assets are available in the Portfolio, the Portfolio may, under certain circumstances, indemnify interestholders from and against any claim or liability to which such holder may become subject by reason of being or having been an interestholder in the Portfolio. Additionally, in the normal course of business, the Portfolio enters into agreements with service providers that may contain indemnification clauses. The Portfolio's maximum exposure under these arrangements is unknown as this would involve future claims that may be made against the Portfolio that have not yet occurred.

The investment adviser fee is earned by Boston Management and Research (BMR), a wholly-owned subsidiary of EVM, as compensation for management and investment advisory services rendered to the Portfolio. Under the advisory agreement, BMR receives a monthly advisory fee equal to 0.80% annually of the average daily net assets of the Portfolio up to $500 million, and at reduced rates as daily net assets exceed that level. For the year ended October 31, 2006, the advisory fee amounted to $726,984. Pursuant to a sub-advisory agreement, BMR has delegated the investment management of the Portfolio to Atlanta Capital. BMR pays Atlanta Capital a monthly fee for sub-advisory services provided to the Portfolio equal to 0.55% annually of the average daily net assets up to $500 million, and at reduced rates as daily net assets exceed that level. BMR has agreed to reduce the investment adviser fee by an amount equal to that portion of commissions paid to broker dealers in execution of Portfolio transactions that is consideration for third-party research services. For the year ended October 31, 2006, BMR waived $5,640 of its advisory fee. Atlanta Capital, in turn, waived $5,640 of its sub-advisory fee. Except for Trustees of the Portfolio who are not members of EVM's or BMR's organization, officers and Trustees receive remuneration for their services to the Portfolio out of the investment adviser fee and sub-adviser fees. Trustees of the Portfolio who are not affiliated with BMR may elect to defer receipt of all or a percentage of their annual fees in accordance with the terms of the Trustees Deferred Compensation Plan. For the year ended October 31, 2006, no significant amounts have been deferred.

Certain officers and Trustees of the Portfolio are officers of the above organizations.

Purchases and sales of investments, other than short-term obligations, aggregated $60,104,229 and $49,317,488, respectively, for the year ended October 31, 2006.

The cost and unrealized appreciation (depreciation) in value of the investments owned at October 31, 2006, as determined on a federal income tax basis, were as follows:

The Portfolio may trade in financial instruments with off-balance sheet risk in the normal course of its investing activities to assist in managing exposure to various market risks. These financial instruments include written options and financial futures contracts and may involve, to a varying degree, elements of risk in excess of the amounts recognized for financial statement purposes.

The notional or contractual amounts of these instruments represent the investment the Portfolio has in particular classes of financial instruments and does not necessarily represent the amounts potentially subject to risk. The measurement of the risks associated with these instruments is meaningful only when all related and offsetting transactions are considered. The Portfolio did not have any open obligations under these financial instruments at October 31, 2006.

The Portfolio participates with other portfolios and funds managed by BMR and EVM and its affiliates in a $150 million unsecured line of credit agreement with a group of banks. Borrowings will be made by the Portfolio solely to facilitate the handling of unusual and/or unanticipated short-term cash requirements. Interest is charged to each participating portfolio or fund based on its borrowings at an amount above either the Eurodollar rate or Federal Funds rate.

In addition, a fee computed at an annual rate of 0.10% on the daily unused portion of the line of credit is allocated among the participating portfolios and funds at the end of each quarter. The Portfolio did not have any significant borrowings or allocated fees for the year ended October 31, 2006.

In June 2006, the Financial Accounting Standards Board (FASB) issued FASB Interpretation No. 48, (FIN 48) "Accounting for Uncertainty in Income Taxes – an interpretation of FASB Statement No. 109". FIN 48 clarifies the accounting for uncertainty in income taxes recognized in accordance with FASB Statement No. 109, "Accounting for Income Taxes." This interpretation prescribes a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. It also provides guidance on de-recognition, classification, interest and penalties, accounting in interim periods, disclosure and transition. FIN 48 is effective for fiscal years beginning after December 15, 2006. Management is currently evaluating the impact of applying the various provisions of FIN 48.

In September 2006, the FASB Statement of Financial Accounting Standards No. 157 (FAS 157) "Fair Value Measurements". FAS 157 defines fair value, establishes a framework for measuring fair value in accordance with generally accepted accounting principles and expands disclosure about fair value measurements. FAS 157 is effective for fiscal years beginning after November 15, 2007. Management is currently evaluating the impact the adoption of FAS 157 will have on the Portfolio's financial statement disclosures.

We have audited the accompanying statement of assets and liabilities of Tax-Managed Mid-Cap Core Portfolio (the "Portfolio"), including the portfolio of investments as of October 31, 2006, the related statement of operations for the year then ended, the statements of changes in net assets for each of the two years in the period then ended and the supplementary data for each of the four years in the period then ended, and for the period from the start of business, March 1, 2002, to October 31, 2002. These financial statements and supplementary data are the responsibility of the Portfolio's management. Our responsibility is to express an opinion on these financial statements and supplementary data based on our audits.

We conducted our audits in accordance with standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements and supplementary data are free of material misstatement. The Portfolio is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. Our audits included consideration of internal control over financial reporting as a basis for designing audit procedures that are appropriate in the circumstances, but not for the purpose of expressing an opinion on the effectiveness of the Portfolio's internal control over financial reporting. Accordingly, we express no such opinion. An audit also includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements, assessing the accounting principles used and significant estimates made by management, as well as evaluating the overall financial statement presentation. Our procedures included confirmation of securities owned as of October 31, 2006 by correspondence with the custodian and brokers. We believe that our audits provide a reasonable basis for our opinion.

In our opinion, the financial statements and supplementary data referred to above present fairly, in all material respects, the financial position of Tax-Managed Mid-Cap Core Portfolio as of October 31, 2006, the results of its operations for the year then ended, the changes in its net assets for each of the two years in the period then ended and the supplementary data for each of the four years in the period then ended, and for the period from the start of business, March 1, 2002, to October 31, 2002 in conformity with accounting principles generally accepted in the United States of America.

BOARD OF TRUSTEES' ANNUAL APPROVAL OF THE INVESTMENT ADVISORY AND SUB-ADVISORY AGREEMENTS

The Investment Company Act of 1940, as amended (the "1940 Act"), provides, in substance, that each investment advisory agreement between a fund and its investment adviser will continue in effect from year to year only if its continuance is approved at least annually by the fund's board of trustees, including by a vote of a majority of the trustees who are not "interested persons" of the fund ("Independent Trustees") cast in person at a meeting called for the purpose of considering such approval.

At a meeting of the Boards of Trustees (each a "Board") of the Eaton Vance group of mutual funds (the "Eaton Vance Funds") held on March 27, 2006, the Board, including a majority of the Independent Trustees, voted to approve continuation of existing advisory and sub-advisory agreements for the Eaton Vance Funds for an additional one-year period. In voting its approval, the Board relied upon the affirmative recommendation of the Special Committee of the Board, which is a committee comprised exclusively of Independent Trustees. Prior to making its recommendation, the Special Committee reviewed information furnished for a series of meetings of the Special Committee held in February and March 2006. Such information included, among other things, the following:

• An independent report comparing the advisory and related fees paid by each fund with fees paid by comparable funds;

• An independent report comparing each fund's total expense ratio and its components to comparable funds;

• An independent report comparing the investment performance of each fund to the investment performance of comparable funds over various time periods;

• Data regarding investment performance in comparison to relevant peer groups of funds and appropriate indices;

• Comparative information concerning fees charged by each adviser for managing other mutual funds and institutional accounts using investment strategies and techniques similar to those used in managing the fund;

• Profitability analyses for each adviser with respect to each fund managed by it;

• Descriptions of the investment management services provided to each fund, including the investment strategies and processes employed;

• Information concerning the allocation of brokerage and the benefits received by each adviser as a result of brokerage allocation, including information concerning the acquisition of research through "soft dollar" benefits received in connection with the funds' brokerage, and the implementation of a soft dollar reimbursement program established with respect to the funds;

• The procedures and processes used to determine the fair value of fund assets and actions taken to monitor and test the effectiveness of such procedures and processes;

• Descriptions of the qualifications, education and experience of the individual investment professionals whose responsibilities include portfolio management and investment research for the funds, and information relating to their compensation and responsibilities with respect to managing other mutual funds and investment accounts;

• Copies of the Codes of Ethics of each adviser and its affiliates, together with information relating to compliance with and the administration of such codes;

• Information concerning the resources devoted to compliance efforts undertaken by each adviser and its affiliates on behalf of the funds (including descriptions of various compliance programs) and their record of compliance with investment policies and restrictions, including policies with respect to market-timing, late trading and selective portfolio disclosure, and with policies on personal securities transactions;

• Descriptions of the business continuity and disaster recovery plans of each adviser and its affiliates;

• Information concerning the nature, cost and character of the administrative and other non-investment management services provided by Eaton Vance Management and its affiliates;

• Information concerning management of the relationship with the custodian, subcustodians and fund accountants by each adviser or the funds' administrator; and

In addition to the information identified above, the Special Committee considered information provided from time to time by each adviser throughout the year at meetings of the Board and its committees. Over the course of the twelve month period ended March 31,

BOARD OF TRUSTEES' ANNUAL APPROVAL OF THE INVESTMENT ADVISORY AND SUB-ADVISORY AGREEMENTS _CONT'D

2006, the Board met nine times and the Special Committee, the Audit Committee and the Governance Committee, each of which is a Committee comprised solely of Independent Trustees, met eight, twelve and five times, respectively. At such meetings, the Trustees received, among other things, presentations by the portfolio managers and other investment professionals of each adviser relating to the investment performance of each fund and the investment strategies used in pursuing the fund's investment objective.

For funds that invest through one or more underlying portfolios, the Board considered similar information about the portfolio(s) when considering the approval of advisory agreements. In addition, in cases where the fund's investment adviser has engaged a sub-adviser, the Board considered similar information about the sub-adviser when considering the approval of any sub-advisory agreement.

The Special Committee was assisted throughout the contract review process by Goodwin Procter LLP, legal counsel for the Independent Trustees. The members of the Special Committee relied upon the advice of such counsel and their own business judgment in determining the material factors to be considered in evaluating each advisory and sub-advisory agreement and the weight to be given to each such factor. The conclusions reached with respect to each advisory and sub-advisory agreement were based on a comprehensive evaluation of all the information provided and not any single factor. Moreover, each member of the Special Committee may have placed varying emphasis on particular factors in reaching conclusions with respect to each advisory and sub-advisory agreement.

Based on its consideration of the foregoing, and such other information as it deemed relevant, including the factors and conclusions described below, the Special Committee concluded that the continuance of the investment advisory agreement of the Tax-Managed Mid-Cap Core Portfolio (the "Portfolio"), the portfolio in which the Eaton Vance Tax-Managed Mid-Cap Core Fund (the "Fund") invests, with Boston Management and Research (the "Adviser"), and the sub-advisory agreement with Atlanta Capital Management Company, LLC (the "Sub-adviser"), including their fee structures, is in the interests of shareholders and, therefore, the Special Committee recommended to the Board approval of the respective agreements. The Board accepted the recommendation of the Special Committee as well as the factors considered and conclusions reached by the Special Committee with respect to the agreements. Accordingly, the Board, including a majority of the Independent Trustees, voted to approve continuation of the investment advisory agreement and the sub-advisory agreement for the Portfolio.

In considering whether to approve the investment advisory agreement and sub-advisory agreements of the Portfolio, the Board evaluated the nature, extent and quality of services provided to the Portfolio by the Adviser and the Sub-adviser.

The Board considered the Adviser's and the Sub-adviser's management capabilities and investment process with respect to the types of investments held by the Portfolio, including the education, experience and number of its investment professionals and other personnel who provide portfolio management, investment research, and similar services to the Portfolio and whose responsibilities include supervising the Sub-adviser. The Board specifically noted the Adviser's in-house equity research capabilities. The Board also took into account the resources dedicated to portfolio management and other services, including the compensation paid to recruit and retain investment personnel, and the time and attention devoted to each Portfolio in the complex by senior management. With respect to the Sub-adviser, the Board took into account the resources available to the Sub-adviser in fulfilling its duties under the sub-advisory agreement and the Sub-adviser's experience in managing equity portfolios, as well as recent changes in personnel.

The Board reviewed the compliance programs of the Adviser and relevant affiliates thereof, including the Sub-adviser. Among other matters, the Board considered compliance and reporting matters relating to personal trading by investment personnel, selective disclosure of portfolio holdings, late trading, frequent trading, portfolio valuation, business continuity and the allocation of investment opportunities. The Board also evaluated the responses of the Adviser and its affiliates to requests from regulatory authorities such as the Securities and Exchange Commission and the National Association of Securities Dealers.

The Board considered shareholder and other administrative services provided or managed by Eaton Vance Management and its affiliates, including transfer agency and accounting services. The Board evaluated the benefits to shareholders of investing in a fund that is a part of a large family of funds, including the ability, in many cases, to exchange an investment among different funds without incurring additional sales charges.

After consideration of the foregoing factors, among others, the Board concluded that the nature, extent and quality of services provided by the Adviser and Sub-adviser, taken as a whole, are appropriate and consistent with the terms of the investment advisory agreement and sub-advisory agreement, respectively.

BOARD OF TRUSTEES' ANNUAL APPROVAL OF THE INVESTMENT ADVISORY AND SUB-ADVISORY AGREEMENTS _CONT'D

The Board compared the Fund's investment performance to a relevant universe of similarly managed funds identified by an independent data provider and appropriate benchmark indices. The Board reviewed comparative performance data for the one- and three- year periods ended September 30, 2005 for the Fund. The Board noted that action was being taken to improve the performance of the Fund, including changes in personnel, and concluded that it was appropriate to allow reasonable time to evaluate the effectiveness of this action.

The Board reviewed contractual investment advisory fee rates, including administrative fee rates, payable by the Portfolio and the Fund (referred to collectively as "management fees").

As part of its review, the Board considered the management fees (including administrative fees) and the Fund's total expense ratio for the one-year period ended September 30, 2005, as compared to a group of similarly managed funds selected by an independent data provider. The Board considered the fact that the Adviser waived fees and/or paid expenses for the Fund.

After reviewing the foregoing information, and in light of the nature, extent and quality of the services provided by the Adviser, the Board concluded that the management fees charged for advisory and related services and the Fund's total expense ratio are reasonable.

The Board reviewed the level of profits realized by the Adviser and relevant affiliates thereof, including the Sub-adviser, in providing investment advisory and administrative services to the Portfolio, the Fund and to all Eaton Vance Funds as a group. The Board considered the level of profits realized without regard to revenue sharing or other payments by the Adviser and its affiliates to third parties in respect of distribution services. The Board also considered other direct or indirect benefits received by the Adviser and its affiliates in connection with its relationship with the Portfolio and the Fund, including the benefits of research services that may be available to the Adviser or Sub-adviser as a result of securities transactions effected for the Portfolio and other advisory clients.

The Board concluded that, in light of the foregoing factors and the nature, extent and quality of the services rendered, the profits realized by the Adviser and its affiliates, including the Sub-adviser, are reasonable.

In reviewing management fees and profitability, the Board also considered the extent to which the Adviser and its affiliates, on the one hand, and the Fund, on the other hand, can expect to realize benefits from economies of scale as the assets of the Fund and the Portfolio increase. The Board acknowledged the difficulty in accurately measuring the benefits resulting from the economies of scale with respect to the management of any specific fund or group of funds. The Board reviewed data summarizing the increases and decreases in the assets of the Fund and of all Eaton Vance Funds as a group over various time periods, and evaluated the extent to which the total expense ratio of the Fund and the profitability of the Adviser and its affiliates may have been affected by such increases or decreases. Based upon the foregoing, the Board concluded that the benefits from economies of scale are currently being shared equitably by the Adviser and its affiliates and the Fund. The Board also concluded that, assuming reasonably foreseeable increases in the assets of the Portfolio, the structure of the advisory fee, which includes breakpoints at several asset levels, can be expected to cause the Adviser and its affiliates and the Fund to continue to share such benefits equitably.

Fund Management. The Trustees of Eaton Vance Mutual Funds Trust (the Trust) and Tax-Managed Mid-Cap Core Portfolio (the Portfolio) are responsible for the overall management and supervision of the Trust's and Portfolio's affairs. The Trustees and officers of the Trust and the Portfolio are listed below. Except as indicated, each individual has held the office shown or other offices in the same company for the last five years. Trustees and officers of the Trust and the Portfolio hold indefinite terms of office. The "noninterested Trustees" consist of those Trustees who are not "interested persons" of the Trust and the Portfolio, as that term is defined under the 1940 Act. The business address of each Trustee and officer is The Eaton Vance Building, 255 State Street, Boston, Massachusetts 02109. As used below, "EVC" refers to Eaton Vance Corp., "EV" refers to Eaton Vance, Inc., "EVM" refers to Eaton Vance Management, "BMR" refers to Boston Management and Research, "Parametric" refers to Parametric Portfolio Associates, "EVD" refers to Eaton Vance Distributors, Inc. and "Atlanta Capital" refers to Atlanta Capital Management Company, LLC. EVC and EV are the corporate parent and trustee, respectively, of EVM and BMR. EVD is the Fund's principal underwriter, the Portfolio's placement agent and a wholly-owned subsidiary of EVM. Each officer affiliated with Eaton Vance may hold a position with other Eaton Vance affiliates that is comparable to his or her position with EVM listed below.

⁽²⁾ Prior to 2005, Ms. Campbell served as Assistant Treasurer of the Trust since 1995. Prior to 2002, Ms. Green served as Assistant Treasurer of the Portfolio since 2001.

The SAI for the Fund includes additional information about the Trustees and officers of the Fund and the Portfolio and can be obtained without charge by calling 1-800-225-6265.

Investment Adviser of Tax-Managed Mid-Cap Core Portfolio
Boston Management and Research

Sub-Adviser of Tax-Managed Mid-Cap Core Portfolio
Atlanta Capital Management Company LLC

Administrator of Eaton Vance Tax-Managed Mid-Cap Core Fund
Eaton Vance Management

This report must be preceded or accompanied by a current prospectus. Before investing, investors should consider carefully the Fund's investment
objective, risks, and charges and expenses. The Fund's current prospectus contains this and other information about the Fund and is available
through your financial advisor. Please read the prospectus carefully before you invest or send money. For further information please call 1-800-225-6265.

Item 2. Code of Ethics

The registrant has adopted a code of ethics applicable to its Principal Executive Officer, Principal Financial Officer and Principal Accounting Officer. The registrant undertakes to provide a copy of such code of ethics to any person upon request, without charge, by calling 1-800-262-1122.

Item 3. Audit Committee Financial Expert

The registrant’s Board has designated William H. Park, Samuel L. Hayes, III and Norton H. Reamer, each an independent trustee, as its audit committee financial experts. Mr. Park is a certified public accountant who is the Vice Chairman of Commercial Industrial Finance Corp (specialty finance company). Previously, he served as President and Chief Executive Officer of Prizm Capital Management, LLC (investment management firm) and as Executive Vice President and Chief Financial Officer of United Asset Management Corporation (“UAM”) (a holding company owning institutional investment management firms). Mr. Hayes is the Jacob H. Schiff Professor of Investment Banking Emeritus of the Harvard University Graduate School of Business Administration. Mr. Reamer is the President, Chief Executive Officer and a Director of Asset Management Finance Corp. (a specialty finance company serving the investment management industry) and is President of Unicorn Corporation (an investment and financial advisory services company). Formerly, Mr. Reamer was Chairman and Chief Operating Officer of Hellman, Jordan Management Co., Inc. (an investment management company) and Advisory Director of Berkshire Capital Corporation (an investment banking firm), Chairman of the Board of UAM and Chairman, President and Director of the UAM Funds (mutual funds).

Item 4. Principal Accountant Fees and Services

(a)-(d)

The following table presents the aggregate fees billed to the registrant for the fiscal years ended October 31, 2005 and October 31, 2006 by the registrant’s principal accountant for professional services rendered for the audit of the registrant’s annual financial statements and fees billed for other services rendered by the principal accountant during those periods.

Fiscal Years Ended	10/31/2005		10/31/2006

Audit Fees	$	19,025	$	21,290

Audit-Related Fees(1)	$	0	$	0

Tax Fees(2)	$	4,305	$	5,470

All Other Fees(3)	$	0	$	0

Total	$	23,330	$	26,760

(1) Audit-related fees consist of the aggregate fees billed for assurance and related services that are reasonably related to the performance of the audit of the registrant’s financial statements and are not reported under the category of audit fees.

(2) Tax fees consist of the aggregate fees billed for professional services rendered by the principal accountant relating to tax compliance, tax advice, and tax planning and specifically include fees for tax return preparation and other tax related compliance/planning matters.

(3) All other fees consist of the aggregate fees billed for products and services provided by the registrant’s principal accountant other than audit, audit-related, and tax services.

(e)(1) The registrant’s audit committee has adopted policies and procedures relating to the pre-approval of services provided by the registrant’s principal accountant (the “Pre-Approval Policies”). The Pre-Approval Policies establish a framework intended to assist the audit committee in the proper discharge of its pre-approval responsibilities. As a general matter, the Pre-Approval Policies (i) specify certain types of audit, audit-related, tax, and other services determined to be pre-approved by the audit committee; and (ii) delineate specific procedures governing the mechanics of the pre-approval process, including the approval and monitoring of audit and non-audit service fees. Unless a service is specifically pre-approved under the Pre-Approval Policies, it must be separately pre-approved by the audit committee.

The Pre-Approval Policies and the types of audit and non-audit services pre-approved therein must be reviewed and ratified by the registrant’s audit committee at least annually. The registrant’s audit committee maintains full responsibility for the appointment, compensation, and oversight of the work of the registrant’s principal accountant.

(e)(2) No services described in paragraphs (b)-(d) above were approved by the registrant’s audit committee pursuant to the “de minimis exception” set forth in Rule 2-01 (c)(7)(i)(C) of Regulation S-X.

(f) Not applicable.

(g) The following table presents (i) the aggregate non-audit fees (i.e., fees for audit-related, tax, and other services) billed to the registrant by the registrant’s principal accountant for the registrant’s fiscal years ended October 31, 2005 and October 31, 2006; and (ii) the aggregate non-audit fees (i.e., fees for audit related, tax, and other services) billed to the Eaton Vance organization by the registrant’s principal accountant for the same time periods.

Fiscal Years Ended	10/31/2005		10/31/2006

Registrant	$	4,305	$	5,470

Eaton Vance(1)	$	223,443	$	72,100

(1)Certain subsidiaries of Eaton Vance Corp. provide ongoing services to the registrant.

(h) The registrant’s audit committee has considered whether the provision by the registrant’s principal accountant of non-audit services to the registrant’s investment adviser and any entity controlling, controlled by, or under common control with the adviser that provides ongoing services to the registrant that were not pre-approved pursuant to Rule 2-01(c)(7)(ii) of Regulation S-X is compatible with maintaining the principal accountant’s independence.

Item 5. Audit Committee of Listed registrants

Not required in this filing.

Item 6. Schedule of Investments

Please see schedule of investments contained in the Report to Stockholders included under Item 1 of this Form N-CSR.

Item 7. Disclosure of Proxy Voting Policies and Procedures for Closed-End Management Investment Companies

Not required in this filing.

Item 8. Portfolio Managers of Closed-End Management Investment Companies

Not required in this filing.

Item 9. Purchases of Equity Securities by Closed-End Management Investment Company and Affiliated Purchasers.

Not required in this filing.

Item 10. Submission of Matters to a Vote of Security Holders.

No Material Changes.

Item 11. Controls and Procedures

(a) It is the conclusion of the registrant’s principal executive officer and principal financial officer that the effectiveness of the registrant’s current disclosure controls and procedures (such disclosure controls and procedures having been evaluated within 90 days of the date of this filing) provide reasonable assurance that the information required to be disclosed by the registrant has been recorded, processed, summarized and reported within the time period specified in the Commission’s rules and forms and that the information required to be disclosed by the registrant has been accumulated and communicated to the registrant’s principal executive officer and principal financial officer in order to allow timely decisions regarding required disclosure.

(b) There have been no changes in the registrant’s internal controls over financial reporting during the second fiscal quarter of the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting.

Item 12. Exhibits

(a)(1)		Registrant’s Code of Ethics – Not applicable (please see Item 2).
(a)(2)(i)		Treasurer’s Section 302 certification.
(a)(2)(ii)		President’s Section 302 certification.
(b)		Combined Section 906 certification.

Investment Company Act file number			811-10597

Tax-Managed Mid-Cap Core Portfolio
(Exact name of registrant as specified in charter)

The Eaton Vance Building, 255 State Street, Boston, Massachusetts					02109
(Address of principal executive offices)					(Zip code)

Alan R. Dynner The Eaton Vance Building, 255 State Street, Boston, Massachusetts 02109
(Name and address of agent for service)

Registrant’s telephone number, including area code:				(617) 482-8260

Date of fiscal year end:	October 31

Date of reporting period:		October 31, 2006

Common Stocks — 98.4%
Security	Shares		Value
Air Freight & Logistics — 2.6%
C.H. Robinson Worldwide, Inc.		29,200	$	1,218,808
Expeditors International of Washington, Inc.		27,800		1,317,998
			$	2,536,806
Airlines — 1.8%
SkyWest, Inc.		66,000	$	1,759,560
			$	1,759,560
Automobiles — 1.1%
Thor Industries, Inc.		25,000	$	1,095,500
			$	1,095,500
Capital Markets — 5.8%
A.G. Edwards, Inc.		20,800	$	1,186,640
Affiliated Managers Group, Inc.⁽¹⁾		18,800		1,882,632
Legg Mason, Inc.		8,700		783,174
SEI Investments Co.		31,800		1,789,704
			$	5,642,150
Chemicals — 3.7%
Albemarle Corp.		21,600	$	1,404,648
Ecolab, Inc.		25,600		1,160,960
RPM International, Inc.		56,000		1,072,400
			$	3,638,008
Commercial Banks — 4.1%
City National Corp.		18,000	$	1,198,080
Cullen/Frost Bankers, Inc.		21,700		1,175,272
Synovus Financial Corp.		57,600		1,692,288
			$	4,065,640
Computer Peripherals — 1.7%
Diebold, Inc.		38,500	$	1,681,680
			$	1,681,680
Construction & Engineering — 1.5%
Jacobs Engineering Group, Inc.⁽¹⁾		19,200	$	1,450,368
			$	1,450,368

Security	Shares		Value
Construction Materials — 0.6%
Florida Rock Industries, Inc.		14,700	$	630,630
			$	630,630
Containers & Packaging — 1.5%
Sonoco Products Co.		40,300	$	1,429,844
			$	1,429,844
Electric Utilities — 1.7%
DPL, Inc.		56,600	$	1,625,552
			$	1,625,552
Electrical Equipment — 4.0%
AMETEK, Inc.		28,000	$	1,307,040
Cooper Industries Ltd. Class A		21,100		1,887,395
Genlyte Group, Inc. (The)⁽¹⁾		10,000		772,600
			$	3,967,035
Electronic Equipment & Instruments — 5.5%
Amphenol Corp. Class A		32,500	$	2,206,750
CDW Corp.		24,300		1,595,781
National Instruments Corp.		51,000		1,590,180
			$	5,392,711
Energy Equipment & Services — 4.1%
FMC Technologies, Inc.⁽¹⁾		32,000	$	1,934,400
Hydril Co.⁽¹⁾		18,000		1,080,900
National Oilwell Varco, Inc.⁽¹⁾		17,000		1,026,800
			$	4,042,100
Food Products — 2.3%
Hormel Foods Corp.		26,000	$	938,860
Tootsie Roll Industries, Inc.		42,230		1,342,069
			$	2,280,929
Gas Utilities — 5.2%
AGL Resources, Inc.		41,100	$	1,541,250
Piedmont Natural Gas Co., Inc.		61,200		1,652,400
Questar Corp.		23,000		1,874,040
			$	5,067,690

Security	Shares		Value
Health Care Equipment & Supplies — 9.9%
Beckman Coulter, Inc.		24,900	$	1,433,493
Biomet, Inc.		24,940		943,730
C.R. Bard, Inc.		15,800		1,294,968
Cooper Cos., Inc., (The)		19,000		1,094,970
DENTSPLY International, Inc.		45,800		1,432,624
Respironics, Inc.⁽¹⁾		48,500		1,713,020
Varian Medical Systems, Inc.⁽¹⁾		32,000		1,755,520
			$	9,668,325
Health Care Providers & Services — 0.5%
Patterson Companies, Inc.⁽¹⁾		16,400	$	538,740
			$	538,740
Hotels, Restaurants & Leisure — 3.6%
Applebee's International, Inc.		43,000	$	981,260
International Speedway Corp. Class A		25,200		1,308,132
Sonic Corp.⁽¹⁾		53,850		1,225,087
			$	3,514,479
Household Durables — 3.5%
Harman International		11,000	$	1,125,850
Hovnanian Enterprises, Inc.⁽¹⁾		34,000		1,048,900
Mohawk Industries, Inc.⁽¹⁾		17,000		1,235,900
			$	3,410,650
Insurance — 5.1%
Ambac Financial Group, Inc.		9,800	$	818,202
Cincinnati Financial Corp.		28,000		1,278,200
Markel Corp.⁽¹⁾		3,800		1,518,100
Protective Life Corp.		31,300		1,385,025
			$	4,999,527
IT Services — 2.7%
Cognizant Technology Solutions Corp., Class A⁽¹⁾		15,000	$	1,129,200
Fiserv, Inc.⁽¹⁾		31,200		1,541,280
			$	2,670,480
Machinery — 3.5%
Dover Corp.		30,300	$	1,439,250
Graco, Inc.		34,200		1,393,992
Pentair, Inc.		17,600		579,744
			$	3,412,986

Security	Shares		Value
Media — 2.7%
E.W. Scripps Co.		25,300	$	1,251,338
Washington Post Co. (The), Class B		1,900		1,430,890
			$	2,682,228
Multiline Retail — 0.9%
Family Dollar Stores, Inc.		30,000	$	883,500
			$	883,500
Multi-Utilities — 3.3%
NSTAR		33,000	$	1,148,070
OGE Energy Corp.		52,800		2,037,024
			$	3,185,094
Office Electronics — 1.8%
Zebra Technologies Corp. Class A⁽¹⁾		46,225	$	1,722,806
			$	1,722,806
Oil, Gas & Consumable Fuels — 1.7%
Holly Corp.		35,000	$	1,664,600
			$	1,664,600
Personal Products — 1.1%
Alberto-Culver Co.		9,450	$	480,154
Estee Lauder Cos., Inc. (The), Class A		14,000		565,460
			$	1,045,614
Real Estate Investment Trusts (REITs) — 1.9%
Developers Diversified Realty Corp.		30,300	$	1,845,270
			$	1,845,270
Semiconductors & Semiconductor Equipment — 2.6%
Microchip Technology, Inc.		42,050	$	1,384,707
Varian Semiconductor Equipment Associates, Inc.⁽¹⁾		31,750		1,158,558
			$	2,543,265
Software — 2.6%
ANSYS, Inc.⁽¹⁾		18,100	$	832,600
Jack Henry & Associates, Inc. Class A		78,500		1,710,515
			$	2,543,115

Assets
Investments, at value (identified cost, $74,674,629)	$	96,279,877
Cash		1,648,798
Dividends and interest receivable		60,446
Total assets	$	97,989,121
Liabilities
Payable to affiliate for investment advisory fees	$	64,310
Payable to affiliate for Trustees' fees		899
Other accrued expenses		47,160
Total liabilities	$	112,369
Net Assets applicable to investors' interest in Portfolio	$	97,876,752
Sources of Net Assets
Net proceeds from capital contributions and withdrawals	$	76,271,504
Net unrealized appreciation (computed on the basis of identified cost)		21,605,248
Total	$	97,876,752

Investment Income
Dividends	$	1,035,329
Interest		50,000
Total investment income	$	1,085,329
Expenses
Investment adviser fee	$	726,984
Trustees' fees and expenses		7,198
Custodian fee		64,502
Legal and accounting services		27,811
Miscellaneous		3,004
Total expenses	$	829,499
Deduct — Reduction of investment adviser fee	$	5,640
Total expense reductions	$	5,640
Net expenses	$	823,859
Net investment income	$	261,470
Realized and Unrealized Gain (Loss)
Net realized gain (loss) — Investment transactions (identified cost basis)	$	4,855,443
Net realized gain	$	4,855,443
Change in unrealized appreciation (depreciation) — Investments (identified cost basis)	$	6,129,045
Net change in unrealized appreciation (depreciation)	$	6,129,045
Net realized and unrealized gain	$	10,984,488
Net increase in net assets from operations	$	11,245,958

Increase (Decrease) in Net Assets	Year Ended October 31, 2006			Year Ended October 31, 2005
From operations — Net investment income (loss)	$	261,470		$	(78,542	)
Net realized gain from investment transactions		4,855,443			1,310,390
Net change in unrealized appreciation (depreciation) of investments		6,129,045			5,930,816
Net increase in net assets from operations	$	11,245,958		$	7,162,664
Capital transactions — Contributions	$	16,793,678		$	8,294,624
Withdrawals		(6,253,468	)		(6,496,638	)
Net increase in net assets from capital transactions	$	10,540,210		$	1,797,986
Net increase in net assets	$	21,786,168		$	8,960,650
Net Assets
At beginning of year	$	76,090,584		$	67,129,934
At end of year	$	97,876,752		$	76,090,584

	Year Ended October 31,												Period Ended
	2006			2005			2004			2003			October 31, 2002⁽¹⁾
Ratios/Supplemental Data
Ratios (As a percentage of average daily net assets):
Expenses⁽³⁾		0.91	%		0.91	%		0.93	%		0.99	%		1.68	%⁽²⁾
Net investment income (loss)		0.29	%		(0.11	)%		(0.15	)%		(0.22	)%		(0.81	)%⁽²⁾
Portfolio Turnover		55	%		53	%		42	%		50	%		13	%
Total Return⁽⁴⁾		13.85	%		10.54	%		6.43	%		25.97	%		(14.72	)%
Net assets, end of year (000's omitted)	$	97,877		$	76,091		$	67,130		$	46,112		$	17,149

Aggregate cost	$	74,741,799
Gross unrealized appreciation	$	21,618,296
Gross unrealized depreciation		(80,218	)
Net unrealized appreciation	$	21,538,078

By:	/s/ James B. Hawkes
	James B. Hawkes
	President


Date:	December 19, 2006

By:	/s/ Michelle A. Green
	Michelle A. Green
	Treasurer


Date:	December 19, 2006