N-CSRS

Item 1: Report to Shareholders

 Total Equity Market Index Fund June 30, 2006 

The views and opinions in this report were current as of June 30, 2006. They are not guarantees of performance or investment results and should not be taken as investment advice. Investment decisions reflect a variety of factors, and the managers reserve the right to change their views about individual stocks, sectors, and the markets at any time. As a result, the views expressed should not be relied upon as a forecast of the fund’s future investment intent. The report is certified under the Sarbanes-Oxley Act of 2002, which requires mutual funds and other public companies to affirm that, to the best of their knowledge, the information in their financial reports is fairly and accurately stated in all material respects.

REPORTS ON THE WEB

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Fellow Shareholders

U.S. stocks generally rose in the first half of 2006, but a sharp stock market decline from mid-May to mid-June erased a large portion of their earlier gains. Investor sentiment—which had been favorable amid hopes that the Federal Reserve would soon stop increasing short-term interest rates—deteriorated rapidly in mid-May due to concerns that rising inflation would force the central bank to raise rates more than investors had expected, which, in turn, could crimp economic and corporate profit growth. In response, investors became risk averse and shunned traditional growth stocks and other aggressive investments.

MARKET ENVIRONMENT

The economy accelerated at the beginning of 2006, expanding at a robust annualized rate of 5.6% in the first quarter versus a sluggish 1.7% in the final quarter of 2005, following last year’s hurricane assault on the Gulf Coast. In the second quarter, however, growth showed signs of moderating. Consumer spending decelerated with rising interest rates and stubbornly high oil and gas prices. Also, gradually rising mortgage rates helped cool the housing market without a significant economic disruption, and job growth softened. On the other hand, business investment has been strong, manufacturing activity seems healthy, and the unemployment rate dipped to a cyclical low of 4.6% in May and June.

Although inflation has been mostly contained, Federal Reserve officials have expressed concerns that the strong economy and rising commodity prices could push inflation higher. In recent weeks, Fed officials have increasingly noted that certain measures of inflation are at or above the upper end of their comfort zone. In response, the central bank—now led by Ben Bernanke following Alan Greenspan’s retirement at the end of January—raised the federal funds target rate in the last six months from 4.25% to 5.25%, a level not seen in five years. The central bank has now lifted the target rate 17 times since mid-2004.

Large-cap shares, as measured by the S&P 500 Stock Index, returned 2.70% in the first half of 2006 versus 5.51% for the Dow Jones Wilshire 4500 Completion Index, a broad benchmark for small- and mid-cap stocks. As measured by various Russell indexes, value stocks did better than growth across all market capitalizations, particularly among large-cap companies.

SUMMARY OF INVESTMENT STRATEGIES

T. Rowe Price’s equity market index funds are designed for investors who want to harness the potential for long-term capital appreciation from broad exposure to large-cap stocks (Equity Index 500 Fund), small-and mid-cap stocks (Extended Equity Market Index Fund), or the entire U.S. stock market (Total Equity Market Index Fund). These funds could serve as core holdings in an investor’s portfolio, as they offer many attributes that most investors will find appealing.

• They are well diversified, which can reduce the potentially negative impact of a given stock on the entire portfolio. The Equity Index 500 Fund invests in all S&P 500 Index stocks, while the Total Equity Market Index Fund and the Extended Equity Market Index Fund invested in approximately 1,850 and 2,400 stocks, respectively, as of June 30.

• They tend to closely track their benchmarks. The Equity Index 500 Fund uses a full replication strategy so that the weightings of our holdings match those of the S&P 500 Index. The Total Equity Market Index Fund and the Extended Equity Market Index Fund use a sampling strategy to approximate the sector allocations, price/earnings ratio, and other attributes of their benchmarks. We occasionally invest in securities such as futures and exchange-traded funds (ETFs) so that the index funds can accommodate cash flows and remain fully invested.

• They offer instant, broad exposure to different sectors of the stock market, and each fund’s sector allocations are consistent with its benchmark’s sector breakdown. As such, changes in the funds’ sector diversification and other overall characteristics reflect changes in the composition of the indexes, rather than strategic shifts that are typical of an actively managed fund.

• Their expenses are generally very low, which enables investors to retain more of their returns. In general, T. Rowe Price’s equity index funds’ expense ratios are well below those of their peer group averages, as measured by Lipper.

EQUITY INDEX 500 FUND

Your fund returned 2.54% in the first half of our fiscal year and 8.30% for the 12-month period ended June 30, 2006. As shown in the table, the fund closely tracked the performance of its benchmark, the S&P 500 Stock Index, in both periods. Fund performance tends to slightly trail that of the benchmark due to annual operating and management expenses.

As measured by various S&P 500 sectors, energy and telecommunication services stocks did best in percentage terms in the last six months. Energy shares contributed significantly to fund and index performance as oil prices remained elevated, with broad strength from integrated oil majors and equipment and services companies. Telecommunication services companies, though they represent less than 4% of the S&P 500, also produced strong gains as a result of industry consolidation.

Industrials and business services and materials stocks did well, buoyed by the strong economy. The former were led by aerospace and defense companies as well as machinery stocks, though industrial giant General Electric remained disappointing; the latter were driven primarily by metals and mining companies, which were fired up by the highest precious metals prices in a generation. (Please refer to the fund’s portfolio of investments for a complete listing of the fund’s holdings and the amount each represents in the portfolio.)

Other sectors generated milder gains, in some cases because of mixed performance of underlying industries. For example, in the financials sector, companies tied to the capital markets, such as brokerages and asset managers, and commercial banks did well, but insurers lagged, hurt by rising interest rates and poor performance of insurance giant American International Group. Similarly, in the consumer discretionary sector, strength in media giants Comcast and Disney was partially offset by poor performance of homebuilding stocks and home improvement retailers Home Depot and Lowes amid a housing market slowdown.

The health care and information technology sectors declined moderately in the last six months. Health care was dragged lower by weakness among managed care companies, particularly UnitedHealth Group, whose options-granting practices are being investigated by securities regulators. Equipment and supply companies also struggled amid concerns about future business prospects as well as some product recalls and antitrust investigations by the Department of Justice. Pharmaceuticals held up relatively well, as gains in Merck, Abbott Laboratories, and Bristol-Myers Squibb were offset to some extent by weakness among other drug stocks.

Information technology stocks detracted the most from the fund’s performance. Semiconductor companies fared worst. In fact, almost all major underlying segments declined, though communications equipment companies, especially Cisco Systems and Corning, did well. Internet software company Google was another bright spot, but its gains were eclipsed by weakness in online auctioneer eBay.

Standard & Poor’s authorized 15 changes to the composition of the S&P 500 Index in the first half of 2006. Many of the stocks that left the index were acquired; a few filed for bankruptcy or were de-listed. Please see the table on page 10 for a complete list of index changes thus far in 2006.

TOTAL EQUITY MARKET INDEX FUND

Your fund returned 3.35% in the first half of our fiscal year and 9.88% in the 12-month period ended June 30, 2006. As shown in the table, the fund closely tracked the performance of its benchmark, the Dow Jones Wilshire 5000 Composite Index, in both periods. The fund typically lags its benchmark slightly due to annual operating and management expenses.

In general, what is true about the performance of the S&P 500 Index is also true about the performance of the Dow Jones Wilshire 5000 Composite Index. The Wilshire 5000 index, which represents the entire U.S. stock market, includes all S&P 500 companies. In fact, the S&P 500 represents 75% of the Wilshire 5000’s total market value. The largest components of the Wilshire index—as with the S&P 500—have the greatest influence on performance. In addition, the percentage weightings of the major sectors are somewhat similar.

In the last six months, telecommunication services and energy shares did best in percentage terms, but materials and industrials and business services stocks also performed well. Utilities, consumer staples, and financials produced milder gains but still outperformed the broad market. Consumer discretionary shares lagged, while information technology and health care stocks declined.

EXTENDED EQUITY MARKET INDEX FUND

Your fund returned 5.60% in the first half of our fiscal year and 13.70% in the 12-month period ended June 30, 2006. Because of favorable stock selection in the course of replicating the index, the fund nosed past the Dow Jones Wilshire 4500 Completion Index in the last six months, as shown in the Performance Comparison table, but it narrowly trailed the benchmark for the one-year period. The fund typically lags its benchmark by a wider margin due to annual operating and management expenses.

In the last six months, the telecommunication services sector did best in percentage terms, thanks to strength in several wireless and diversified telecom companies, though the sector represents about 2% of the small- and mid-cap universe. Similarly, materials stocks, which account for less than 5% of the index, rose strongly, propelled by brisk gains among metals and mining stocks, thanks to surging metals prices.

The industrials and business services segment advanced significantly and, because of its sizable representation in the index (more than 11%), contributed the most to fund and index performance. Most underlying industries posted gains, led by machinery stocks and air freight and logistics companies. Building products and airlines generally lagged. Energy shares advanced strongly in the last six months because of heightened oil prices and despite the mid-May to mid-June sell-off.

The consumer staples, utilities, and financials sectors produced milder gains but outperformed the index in the first half of the year. Consumer discretionary shares lagged, as strength in gaming, hotel, and restaurant stocks offset weakness in other areas, such as homebuilding stocks and various media companies.

Information technology shares were widely mixed in the last six months, as strength in IT services companies, electronic equipment, and semiconductor companies was offset by poor performance of software and Internet software stocks. Health care stocks declined, with biotechnology shares weighing most heavily on the sector amid greater risk aversion from investors. Pharmaceuticals also struggled, but other segments held up well.

OUTLOOK

The equity market environment is perhaps more uncertain than it has been since the beginning of the current bull market about three-and-a-half years ago. Geopolitical concerns, the possibility of additional rate increases from the Fed, inflation worries, and signs of slower economic growth are some of the factors weighing on the market. On the other hand, healthy corporate balance sheets, earnings, and business spending should be supportive.

As the tug of war between bullish and bearish forces plays itself out, some sectors will inevitably do better than others—which underscores the value of having a broadly diversified portfolio, particularly during periods of market volatility—but we will not try to predict which investments will perform best. Our task is to track closely the major U.S. equity indexes with the assets you have entrusted to us.

Respectfully submitted,

E. Frederick Bair
Chairman of the Investment Advisory Committee, Equity Index 500 Fund and Extended Equity Market Index Fund
Co-chairman of the Investment Advisory Committee, Total Equity Market Index Fund

Ken D. Uematsu
Co-chairman of the Investment Advisory Committee, Total Equity Market Index Fund

July 17, 2006

The committee chairmen have day-to-day responsibility for managing the portfolios and work with committee members in developing and executing the funds’ investment programs.

RISKS OF INVESTING

As with all stock mutual funds, the funds’ share prices can fall because of weakness in the stock market, a particular industry, or specific holdings. Stock markets can decline for many reasons, including adverse political or economic developments, changes in investor psychology, or heavy institutional selling. The prospects for an industry or company may deteriorate because of a variety of factors, including disappointing earnings or changes in the competitive environment.

GLOSSARY

Dow Jones Wilshire 4500 Completion Index: Tracks the performance of all stocks in the Dow Jones Wilshire 5000 Composite Index, excluding those in the S&P 500 Stock Index.

Dow Jones Wilshire 5000 Composite Index: Tracks the performance of the most active stocks in the broad U.S. market.

Fed funds target rate: An overnight lending rate set by the Federal Reserve and used by banks to meet reserve requirements. Banks also use the fed funds rate as a benchmark for their prime lending rates.

S&P 500 Stock Index: Tracks the stocks of 500 mostly large U.S. companies.

GROWTH OF $10,000 

This chart shows the value of a hypothetical $10,000 investment in the fund over the past 10 fiscal year periods or since inception (for funds lacking 10-year records). The result is compared with benchmarks, which may include a broad-based market index and a peer group average or index. Market indexes do not include expenses, which are deducted from fund returns as well as mutual fund averages and indexes.

AVERAGE ANNUAL COMPOUND TOTAL RETURN 

This table shows how the fund would have performed each year if its actual (or cumulative) returns for the periods shown had been earned at a constant rate.

GROWTH OF $10,000 

This chart shows the value of a hypothetical $10,000 investment in the fund over the past 10 fiscal year periods or since inception (for funds lacking 10-year records). The result is compared with benchmarks, which may include a broad-based market index and a peer group average or index. Market indexes do not include expenses, which are deducted from fund returns as well as mutual fund averages and indexes.

AVERAGE ANNUAL COMPOUND TOTAL RETURN 

This table shows how the fund would have performed each year if its actual (or cumulative) returns for the periods shown had been earned at a constant rate.

GROWTH OF $10,000 

This chart shows the value of a hypothetical $10,000 investment in the fund over the past 10 fiscal year periods or since inception (for funds lacking 10-year records). The result is compared with benchmarks, which may include a broad-based market index and a peer group average or index. Market indexes do not include expenses, which are deducted from fund returns as well as mutual fund averages and indexes.

AVERAGE ANNUAL COMPOUND TOTAL RETURN 

This table shows how the fund would have performed each year if its actual (or cumulative) returns for the periods shown had been earned at a constant rate.

FUND EXPENSE EXAMPLE 

As a mutual fund shareholder, you may incur two types of costs: (1) transaction costs, such as redemption fees or sales loads, and (2) ongoing costs, including management fees, distribution and service (12b-1) fees, and other fund expenses. The following example is intended to help you understand your ongoing costs (in dollars) of investing in the fund and to compare these costs with the ongoing costs of investing in other mutual funds. The example is based on an investment of $1,000 invested at the beginning of the most recent six-month period and held for the entire period.

Actual Expenses
The first line of the following table (“Actual”) provides information about actual account values and actual expenses. You may use the information in this line, together with your account balance, to estimate the expenses that you paid over the period. Simply divide your account value by $1,000 (for example, an $8,600 account value divided by $1,000 = 8.6), then multiply the result by the number in the first line under the heading “Expenses Paid During Period” to estimate the expenses you paid on your account during this period.

Hypothetical Example for Comparison Purposes
The information on the second line of the table (“Hypothetical”) is based on hypothetical account values and expenses derived from the fund’s actual expense ratio and an assumed 5% per year rate of return before expenses (not the fund’s actual return). You may compare the ongoing costs of investing in the fund with other funds by contrasting this 5% hypothetical example and the 5% hypothetical examples that appear in the shareholder reports of the other funds. The hypothetical account values and expenses may not be used to estimate the actual ending account balance or expenses you paid for the period.

Note: T. Rowe Price charges an account maintenance fee that is not included in the accompanying table. The account maintenance fee is charged on a quarterly basis, usually during the last week of a calendar quarter, and applies to accounts with balances below $10,000 on the day of the assessment. The fee is charged to accounts that fall below $10,000 for any reason, including market fluctuations, redemptions, or exchanges. When an account with less than $10,000 is closed either through redemption or exchange, the fee is charged and deducted from the proceeds. The fee applies to IRA accounts but not to retirement plans directly registered with T. Rowe Price Services or accounts maintained by intermediaries through NSCC® Networking. If you are subject to the fee, keep it in mind when you are estimating the ongoing expenses of investing in the fund and when comparing the expenses of this fund with other funds.

You should also be aware that the expenses shown in the table highlight only your ongoing costs and do not reflect any transaction costs, such as redemption fees or sales loads. Therefore, the second line of the table is useful in comparing ongoing costs only and will not help you determine the relative total costs of owning different funds. To the extent a fund charges transaction costs, however, the total cost of owning that fund is higher.

Unaudited

The accompanying notes are an integral part of these financial statements.

Unaudited

The accompanying notes are an integral part of these financial statements.

Unaudited

The accompanying notes are an integral part of these financial statements.

Unaudited

The accompanying notes are an integral part of these financial statements.

Unaudited

The accompanying notes are an integral part of these financial statements.

Unaudited

NOTES TO FINANCIAL STATEMENTS 

NOTE 1 - SIGNIFICANT ACCOUNTING POLICIES

T. Rowe Price Index Trust, Inc. (the trust), is registered under the Investment Company Act of 1940 (the 1940 Act). The Total Equity Market Index Fund (the fund), a diversified, open-end management investment company, is one portfolio established by the trust. The fund commenced operations on January 30, 1998. The fund seeks to match the performance of the entire U.S. stock market, as represented by the Dow Jones Wilshire 5000 Composite Index.

The accompanying financial statements were prepared in accordance with accounting principles generally accepted in the United States of America, which require the use of estimates made by fund management. Fund management believes that estimates and security valuations are appropriate; however, actual results may differ from those estimates, and the security valuations reflected in the financial statements may differ from the value the fund ultimately realizes upon sale of the securities.

Valuation The fund values its investments and computes its net asset value per share at the close of the New York Stock Exchange (NYSE), normally 4 p.m. ET, each day that the NYSE is open for business. Equity securities listed or regularly traded on a securities exchange or in the over-the-counter (OTC) market are valued at the last quoted sale price at the time the valuations are made, except for OTC Bulletin Board securities, which are valued at the mean of the latest bid and asked prices. A security that is listed or traded on more than one exchange is valued at the quotation on the exchange determined to be the primary market for such security. Listed securities not traded on a particular day are valued at the mean of the latest bid and asked prices. Debt securities with original maturities of less than one year are valued at amortized cost in local currency, which approximates fair value when combined with accrued interest.

Investments in mutual funds are valued at the mutual fund’s closing net asset value per share on the day of valuation. Financial futures contracts are valued at closing settlement prices.

Other investments, including restricted securities, and those for which the above valuation procedures are inappropriate or are deemed not to reflect fair value are stated at fair value as determined in good faith by the T. Rowe Price Valuation Committee, established by the fund’s Board of Trustees.

Redemption Fees A 0.5% fee is assessed on redemptions of fund shares held less than 90 days/3 months to deter short-term trading and to protect the interests of long-term shareholders. Redemption fees are withheld from proceeds that shareholders receive from the sale or exchange of fund shares. The fees are paid to the fund, and are recorded as an increase to paid-in capital. The fees may cause the redemption price per share to differ from the net asset value per share.

Investment Transactions, Investment Income, and Distributions Income and expenses are recorded on the accrual basis. Premiums and discounts on debt securities are amortized for financial reporting purposes. Dividends received from mutual fund investments are reflected as dividend income; capital gain distributions are reflected as realized gain/loss. Dividend income and capital gain distributions are recorded on the ex-dividend date. Investment transactions are accounted for on the trade date. Realized gains and losses are reported on the identified cost basis. Payments (“variation margin”) made or received to settle the daily fluctuations in the value of futures contracts are recorded as unrealized gains or losses until the contracts are closed. Unsettled variation margin on futures contracts is reflected as other assets or liabilities, and unrealized gains and losses on futures contracts are reflected as the change in net unrealized gain or loss in the accompanying financial statements. Distributions to shareholders are recorded on the ex-dividend date. Income distributions are declared and paid on an annual basis. Capital gain distributions, if any, are declared and paid by the fund, typically on an annual basis.

NOTE 2 - INVESTMENT TRANSACTIONS

Consistent with its investment objective, the fund engages in the following practices to manage exposure to certain risks or to enhance performance. The investment objective, policies, program, and risk factors of the fund are described more fully in the fund’s prospectus and Statement of Additional Information.

Futures Contracts During the six months ended June 30, 2006, the fund was a party to futures contracts, which provide for the future sale by one party and purchase by another of a specified amount of a specific financial instrument at an agreed upon price, date, time, and place. Risks arise from possible illiquidity of the futures market and from movements in security values.

Securities Lending The fund lends its securities to approved brokers to earn additional income. It receives as collateral cash and U.S. government securities valued at 102% to 105% of the value of the securities on loan. Cash collateral is invested in a money market pooled trust managed by the fund’s lending agent in accordance with investment guidelines approved by fund management. Collateral is maintained over the life of the loan in an amount not less than the value of loaned securities, as determined at the close of fund business each day; any additional collateral required due to changes in security values is delivered to the fund the next business day. Although risk is mitigated by the collateral, the fund could experience a delay in recovering its securities and a possible loss of income or value if the borrower fails to return the securities. Securities lending revenue recognized by the fund consists of earnings on invested collateral and borrowing fees, net of any rebates to the borrower and compensation to the lending agent. At June 30, 2006, the value of loaned securities was $51,208,000; aggregate collateral consisted of $52,182,000 in the money market pooled trust and U.S. government securities valued at $9,000.

Other Purchases and sales of portfolio securities, other than short-term securities, aggregated $19,943,000 and $10,653,000, respectively, for the six months ended June 30, 2006.

NOTE 3 - FEDERAL INCOME TAXES

No provision for federal income taxes is required since the fund intends to continue to qualify as a regulated investment company under Subchapter M of the Internal Revenue Code and distribute to shareholders all of its taxable income and gains. Federal income tax regulations differ from generally accepted accounting principles; therefore, distributions determined in accordance with tax regulations may differ in amount or character from net investment income and realized gains for financial reporting purposes. Financial reporting records are adjusted for permanent book/tax differences to reflect tax character. Financial records are not adjusted for temporary differences. The amount and character of tax-basis distributions and composition of net assets are finalized at fiscal year-end; accordingly, tax-basis balances have not been determined as of June 30, 2006.

For tax purposes, the fund has elected to treat net capital losses realized between November 1 and December 31 of each year as occurring on the first day of the following tax year; consequently, $550,000 of realized losses recognized for financial reporting purposes in the year ended December 31, 2005, were recognized for tax purposes on January 1, 2006. Further, the fund intends to retain realized gains to the extent of available capital loss carryforwards. As of December 31, 2005, the fund had $19,861,000 of unused capital loss carryforwards, of which $5,639,000 expire in 2009, $13,059,000 expire in 2010, and $1,163,000 expire in 2012.

At June 30, 2006, the cost of investments for federal income tax purposes was $382,932,000. Net unrealized gain aggregated $77,450,000 at period-end, of which $110,124,000 related to appreciated investments and $32,674,000 related to depreciated investments.

NOTE 4 - RELATED PARTY TRANSACTIONS

The fund is managed by T. Rowe Price Associates, Inc. (the manager or Price Associates), a wholly owned subsidiary of T. Rowe Price Group, Inc. The investment management and administrative agreement between the fund and the manager provides for an all-inclusive annual fee equal to 0.40% of the fund’s average daily net assets. The fee is computed daily and paid monthly. The agreement provides that investment management, shareholder servicing, transfer agency, accounting, and custody services are provided to the fund, and interest, taxes, brokerage commissions, directors’ fees and expenses, and extraordinary expenses are paid directly by the fund.

Additionally, the fund is one of several mutual funds in which certain college savings plans managed by Price Associates may invest. As approved by the fund’s Board of Directors, shareholder servicing costs associated with each college savings plan are allocated to the fund in proportion to the average daily value of its shares owned by the college savings plan. Shareholder servicing costs allocated to the fund are borne by Price Associates, pursuant to the fund’s all-inclusive fee agreement. At June 30, 2006, less than 1% of the outstanding shares of the fund were held by college savings plans.

The fund may invest in the T. Rowe Price Reserve Investment Fund and the T. Rowe Price Government Reserve Investment Fund (collectively, the T. Rowe Price Reserve Funds), open-end management investment companies managed by Price Associates and affiliates of the fund. The T. Rowe Price Reserve Funds are offered as cash management options to mutual funds, trusts, and other accounts managed by Price Associates and/or its affiliates, and are not available for direct purchase by members of the public. The T. Rowe Price Reserve Funds pay no investment management fees. During the six months ended June 30, 2006, dividend income from the T. Rowe Price Reserve Funds totaled $232,000, and the value of shares of the T. Rowe Price Reserve Funds held at June 30, 2006, and December 31, 2005, was $12,880,000 and $6,019,000, respectively.

As of June 30, 2006, T. Rowe Price Group, Inc. and/or its wholly owned subsidiaries owned 152,943 shares of the fund, representing less than 1% of the fund’s net assets.

INFORMATION ON PROXY VOTING POLICIES, PROCEDURES, AND RECORDS 

A description of the policies and procedures used by T. Rowe Price funds and portfolios to determine how to vote proxies relating to portfolio securities is available in each fund’s Statement of Additional Information, which you may request by calling 1-800-225-5132 or by accessing the SEC’s Web site, www.sec.gov. The description of our proxy voting policies and procedures is also available on our Web site, www.troweprice.com. To access it, click on the words “Company Info” at the top of our homepage for individual investors. Then, in the window that appears, click on the “Proxy Voting Policy” navigation button in the top left corner.

Each fund’s most recent annual proxy voting record is available on our Web site and through the SEC’s Web site. To access it through our Web site, follow the directions above, then click on the words “Proxy Voting Record” at the bottom of the Proxy Voting Policy page.

HOW TO OBTAIN QUARTERLY PORTFOLIO HOLDINGS 

The fund files a complete schedule of portfolio holdings with the Securities and Exchange Commission for the first and third quarters of each fiscal year on Form N-Q. The fund’s Form N-Q is available electronically on the SEC’s Web site (www.sec.gov); hard copies may be reviewed and copied at the SEC’s Public Reference Room, 450 Fifth St. N.W., Washington, DC 20549. For more information on the Public Reference Room, call 1-800-SEC-0330.

APPROVAL OF INVESTMENT MANAGEMENT AGREEMENT 

On March 8, 2006, the fund’s Board of Directors unanimously approved the investment advisory contract (Contract) between the fund and its investment manager, T. Rowe Price Associates, Inc. (Manager). The Board considered a variety of factors in connection with its review of the Contract, also taking into account information provided by the Manager during the course of the year, as discussed below:

Services Provided by the Manager
The Board considered the nature, quality, and extent of the services provided to the fund by the Manager. These services included, but were not limited to, management of the fund’s portfolio and a variety of activities related to portfolio management. The Board also reviewed the background and experience of the Manager’s senior management team and investment personnel involved in the management of the fund. The Board concluded that it was satisfied with the nature, quality, and extent of the services provided by the Manager.

Investment Performance of the Fund
The Board reviewed the fund’s average annual total return over the one-, three-, and five-year and since-inception periods as well as the fund’s year-by-year returns and compared these returns with previously agreed upon comparable performance measures and market data, including those supplied by Lipper and Morningstar, which are independent providers of mutual fund data. On the basis of this evaluation and the Board’s ongoing review of investment results, the Board concluded that the fund’s performance was satisfactory.

Costs, Benefits, Profits, and Economies of Scale
The Board reviewed detailed information regarding the revenues received by the Manager under the Contract and other benefits that the Manager (and its affiliates) may have realized from its relationship with the fund, including research received under “soft dollar” agreements. The Board noted that the use of soft dollars as a means of paying for third-party, non-broker research had been eliminated. The Board also received information on the estimated costs incurred and profits realized by the Manager and its affiliates from advising T. Rowe Price mutual funds, as well as estimates of the gross profits realized from managing the fund in particular. The Board concluded that the Manager’s profits were reasonable in light of the services provided to the fund. The Board also considered whether the fund or other funds benefit under the fee levels set forth in the Contract from any economies of scale realized by the Manager. The Board noted that, under the Contract, the fund pays the Manager a single fee based on the fund’s assets and the Manager, in turn, pays all expenses of the fund, with certain exceptions. The Board concluded that, based on the profitability data it reviewed and consistent with this single fee structure, the Contract provided for a reasonable sharing of benefits from any economies of scale with the fund’s investors.

Fees
The Board reviewed the fund’s single-fee structure and compared the rate with fees and expenses of other comparable funds based on information and data supplied by Lipper. The information provided to the Board indicated that the fund’s single fee rate was generally at or below the median management fee rate and expense ratio for comparable funds. The Board also reviewed the fee schedules for comparable privately managed accounts of the Manager and its affiliates. Management informed the Board that the Manager’s responsibilities for privately managed accounts are more limited than its responsibilities for the fund and other T. Rowe Price mutual funds that it or its affiliates advise. On the basis of the information provided, the Board concluded that the fees paid by the fund under the Contract were reasonable.

Approval of the Contract
As noted, the Board approved the continuation of the Contract. No single factor was considered in isolation or to be determinative to the decision. Rather, the Board concluded, in light of a weighting and balancing of all factors considered, that it was in the best interests of the fund to approve the continuation of the Contract, including the fees to be charged for services thereunder.

Item 2. Code of Ethics.

A code of ethics, as defined in Item 2 of Form N-CSR, applicable to its principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions is filed as an exhibit to the registrant’s annual Form N-CSR. No substantive amendments were approved or waivers were granted to this code of ethics during the registrant’s most recent fiscal half-year.

Item 3. Audit Committee Financial Expert.

Disclosure required in registrant’s annual Form N-CSR.

Item 4. Principal Accountant Fees and Services.

Disclosure required in registrant’s annual Form N-CSR.

Item 5. Audit Committee of Listed Registrants.

Not applicable.

Item 6. Schedule of Investments.

Not applicable. The complete schedule of investments is included in Item 1 of this Form N-CSR.

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

Not applicable.

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

Not applicable.

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

Not applicable.

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

Not applicable.

Item 11. Controls and Procedures.

(a) The registrant’s principal executive officer and principal financial officer have evaluated the registrant’s disclosure controls and procedures within 90 days of this filing and have concluded that the registrant’s disclosure controls and procedures were effective, as of that date, in ensuring that information required to be disclosed by the registrant in this Form N-CSR was recorded, processed, summarized, and reported timely.

(b) The registrant’s principal executive officer and principal financial officer are aware of no change in the registrant’s internal control over financial reporting that occurred during the registrant’s second fiscal quarter 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) The registrant’s code of ethics pursuant to Item 2 of Form N-CSR is filed with the registrant’s annual Form N-CSR.

    (2) Separate certifications by the registrant's principal executive officer and principal financial officer, pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 and required by Rule 30a-2(a) under the Investment Company Act of 1940, are attached.

    (3) Written solicitation to repurchase securities issued by closed-end companies: not applicable.

(b) A certification by the registrant's principal executive officer and principal financial officer, pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 and required by Rule 30a-2(b) under the Investment Company Act of 1940, is attached.

SIGNATURES
	Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment
Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the
undersigned, thereunto duly authorized.
T. Rowe Price Index Trust, Inc.
By	/s/ Edward C. Bernard
	Edward C. Bernard
	Principal Executive Officer
Date	August 18, 2006
	Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment
Company Act of 1940, this report has been signed below by the following persons on behalf of
the registrant and in the capacities and on the dates indicated.
By	/s/ Edward C. Bernard
	Edward C. Bernard
	Principal Executive Officer
Date	August 18, 2006
By	/s/ Joseph A. Carrier
	Joseph A. Carrier
	Principal Financial Officer
Date	August 18, 2006

EX-99.CERT

Item 12(a)(2).

CERTIFICATIONS 

I, Edward C. Bernard, certify that:
1.	I have reviewed this report on Form N-CSR of T. Rowe Price Total Equity Market Index Fund;
2.	Based on my knowledge, this report does not contain any untrue statement of a material fact or omit
	to state a material fact necessary to make the statements made, in light of the circumstances under
	which such statements were made, not misleading with respect to the period covered by this report;
3.	Based on my knowledge, the financial statements, and other financial information included in this
	report, fairly present in all material respects the financial condition, results of operations, changes in
	net assets, and cash flows (if the financial statements are required to include a statement of cash
	flows) of the registrant as of, and for, the periods presented in this report;
4.	The registrant's other certifying officer(s) and I are responsible for establishing and maintaining
	disclosure controls and procedures (as defined in rule 30a-3(c) under the Investment Company Act
	of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the
	Investment Company Act of 1940) for the registrant and have:
	(a) Designed such disclosure controls and procedures, or caused such disclosure controls and
		procedures to be designed under our supervision, to ensure that material information relating to
		the registrant, including its consolidated subsidiaries, is made known to us by others within those
		entities, particularly during the period in which this report is being prepared;
	(b) Designed such internal control over financial reporting, or caused such internal control over
		financial reporting to be designed under our supervision, to provide reasonable assurance
		regarding the reliability of financial reporting and the preparation of financial statements for
		external purposes in accordance with generally accepted accounting principles;
	(c)	Evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in
		this report our conclusions about the effectiveness of the disclosure controls and procedures, as of
		a date within 90 days prior to the filing date of this report based on such evaluation; and
	(d)	Disclosed in this report any change in the registrant’s internal control over financial reporting that
		occurred 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; and
5.	The registrant's other certifying officer(s) and I have disclosed to the registrant's auditors and the
	audit committee of the registrant's board of directors (or persons performing the equivalent
	functions):
	(a)	All significant deficiencies and material weaknesses in the design or operation of internal control
		over financial reporting which are reasonably likely to adversely affect the registrant's ability to
		record, process, summarize, and report financial information; and
	(b)	Any fraud, whether or not material, that involves management or other employees who have a
		significant role in the registrant's internal control over financial reporting.

Date:	August 18, 2006	/s/ Edward C. Bernard
		Edward C. Bernard
		Principal Executive Officer

CERTIFICATIONS 

I, Joseph A. Carrier, certify that:
1.	I have reviewed this report on Form N-CSR of T. Rowe Price Total Equity Market Index Fund;
2.	Based on my knowledge, this report does not contain any untrue statement of a material fact or omit
	to state a material fact necessary to make the statements made, in light of the circumstances under
	which such statements were made, not misleading with respect to the period covered by this report;
3.	Based on my knowledge, the financial statements, and other financial information included in this
	report, fairly present in all material respects the financial condition, results of operations, changes in
	net assets, and cash flows (if the financial statements are required to include a statement of cash
	flows) of the registrant as of, and for, the periods presented in this report;
4.	The registrant's other certifying officer(s) and I are responsible for establishing and maintaining
	disclosure controls and procedures (as defined in rule 30a-3(c) under the Investment Company Act
	of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the
	Investment Company Act of 1940) for the registrant and have:
	(a) Designed such disclosure controls and procedures, or caused such disclosure controls and
		procedures to be designed under our supervision, to ensure that material information relating to
		the registrant, including its consolidated subsidiaries, is made known to us by others within those
		entities, particularly during the period in which this report is being prepared;
	(b) Designed such internal control over financial reporting, or caused such internal control over
		financial reporting to be designed under our supervision, to provide reasonable assurance
		regarding the reliability of financial reporting and the preparation of financial statements for
		external purposes in accordance with generally accepted accounting principles;
	(c)	Evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in
		this report our conclusions about the effectiveness of the disclosure controls and procedures, as of
		a date within 90 days prior to the filing date of this report based on such evaluation; and
	(d)	Disclosed in this report any change in the registrant’s internal control over financial reporting that
		occurred 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; and
5.	The registrant's other certifying officer(s) and I have disclosed to the registrant's auditors and the
	audit committee of the registrant's board of directors (or persons performing the equivalent
	functions):
	(a)	All significant deficiencies and material weaknesses in the design or operation of internal control
		over financial reporting which are reasonably likely to adversely affect the registrant's ability to
		record, process, summarize, and report financial information; and
	(b)	Any fraud, whether or not material, that involves management or other employees who have a
		significant role in the registrant's internal control over financial reporting.

Date:	August 18, 2006	/s/ Joseph A. Carrier
		Joseph A. Carrier
		Principal Financial Officer

EX-99.906 CERT

Item 12(b).
CERTIFICATION UNDER SECTION 906 OF SARBANES-OXLEY ACT OF 2002
Name of Issuer: T. Rowe Price Total Equity Market Index Fund
In connection with the Report on Form N-CSR for the above named issuer, the undersigned hereby
certifies, to the best of his knowledge, that:
1.	The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities
	Exchange Act of 1934;
2.	The information contained in the Report fairly presents, in all material respects, the financial
	condition and results of operations of the Issuer.
Date: August 18, 2006		/s/ Edward C. Bernard
		Edward C. Bernard
		Principal Executive Officer
Date:  August 18, 2006		/s/ Joseph A. Carrier
		Joseph A. Carrier
		Principal Financial Officer