Class K | BlackRock International Index Fund

Fund Overview

Key Facts About BlackRock International Index Fund

Investment Objective

The investment objective of BlackRock International Index Fund (“International Index Fund” or the “Fund”), a series of BlackRock Index Funds, Inc. (the “Corporation”), is to match the performance of the MSCI EAFE Index (Europe, Australasia, Far East) (the “MSCI EAFE Index” or the “Underlying Index”) in U.S. dollars with net dividends as closely as possible before the deduction of Fund expenses.

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold Class K Shares of International Index Fund.

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

Annual Fund Operating Expenses	Class K BlackRock International Index Fund Class K Shares
Management Fee	0.01%
Distribution and/or Service (12b-1) Fees	none
Other Expenses	0.09%	[1],[2]
Total Annual Fund Operating Expenses	0.10%	[2]
Fee Waivers and/or Expense Reimbursements	(0.03%)	[3]
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.07%	[3]

Example:

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Class K | BlackRock International Index Fund | Class K Shares | USD ($)	7	29	53	125

Portfolio Turnover:

International Index Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the Example, affect the Fund’s performance. During the most recent fiscal year, International Index Fund’s portfolio turnover rate was 9% of the average value of its portfolio.

Principal Investment Strategies of the Fund

International Index Fund employs a “passive” management approach, attempting to invest in a portfolio of assets whose performance is expected to match approximately the performance of the MSCI EAFE Index. The Fund will be substantially invested in securities in the MSCI EAFE Index, and will invest, under normal circumstances, at least 80% of its assets in securities or other financial instruments that are components of or have economic characteristics similar to the securities included in the MSCI EAFE Index. The Fund may change its target index if Fund management believes a different index would better enable the Fund to match the performance of the market segment represented by the current index.

International Index Fund invests in a statistically selected sample of equity securities included in the MSCI EAFE Index and in derivative instruments linked to the MSCI EAFE Index. Equity securities include common stock, preferred stock, securities convertible into common stock and securities or other instruments whose price is linked to the value of common stock. The Fund will, under normal circumstances, invest in all of the countries represented in the MSCI EAFE Index. The Fund may not, however, invest in all of the companies within a country represented in the MSCI EAFE Index, or in the same weightings as in the MSCI EAFE Index.

Principal Risks of Investing in the Fund

Risk is inherent in all investing. The value of your investment in International Index Fund, as well as the amount of return you receive on your investment, may fluctuate significantly from day to day and over time. You may lose part or all of your investment in the Fund or your investment may not perform as well as other similar investments. The following is a summary description of principal risks of investing in the Fund.

• Equity Securities Risk — Stock markets are volatile. The price of equity securities fluctuates based on changes in a company’s financial condition and overall market and economic conditions.

• Foreign Securities Risk — Foreign investments often involve special risks not present in U.S. investments that can increase the chances that the Fund will lose money. These risks include:

• The Fund generally holds its foreign securities and cash in foreign banks and securities depositories, which may be recently organized or new to the foreign custody business and may be subject to only limited or no regulatory oversight.

• Changes in foreign currency exchange rates can affect the value of the Fund’s portfolio.

• The economies of certain foreign markets may not compare favorably with the economy of the United States with respect to such issues as growth of gross national product, reinvestment of capital, resources and balance of payments position.

• The governments of certain countries may prohibit or impose substantial restrictions on foreign investments in their capital markets or in certain industries.

• Many foreign governments do not supervise and regulate stock exchanges, brokers and the sale of securities to the same extent as does the United States and may not have laws to protect investors that are comparable to U.S. securities laws.

• Settlement and clearance procedures in certain foreign markets may result in delays in payment for or delivery of securities not typically associated with settlement and clearance of U.S. investments.

• The European financial markets have recently experienced volatility and adverse trends due to concerns about economic downturns in, or rising government debt levels of, several European countries. These events may spread to other countries in Europe. These events may affect the value and liquidity of certain of the Fund’s investments.

• Index Fund Risk — An index fund has operating and other expenses while an index does not. As a result, while the Fund will attempt to track the MSCI EAFE Index as closely as possible, it will tend to underperform the index to some degree over time. If an index fund is properly correlated to its stated index, the fund will perform poorly when the index performs poorly.

• Index-Related Risk — There is no guarantee that the Fund will achieve a high degree of correlation to the Underlying Index and therefore achieve its investment objective. Market disruptions and regulatory restrictions could have an adverse effect on the Fund’s ability to adjust its exposure to the required levels in order to track the Underlying Index. Errors in index data may occur from time to time and may not be identified and corrected for a period of time, and may have an adverse impact on the Fund and its shareholders.

• Market Risk and Selection Risk — Market risk is the risk that one or more markets in which the Fund invests will go down in value, including the possibility that the markets will go down sharply and unpredictably. Selection risk is the risk that the securities selected by Fund management will underperform the markets, the relevant indices or the securities selected by other funds with similar investment objectives and investment strategies. This means you may lose money.

Performance Information

Class K Shares of International Index Fund commenced operations on March 31, 2011. As a result, the returns in the chart and table for Class K Shares, prior to their commencement of operations on March 31, 2011, are based on the Fund’s Institutional Shares, adjusted to reflect the fees and expenses applicable to Class K Shares.

The information shows how the Fund’s performance has varied year by year and provides some indication of the risks of investing in the Fund. The table compares the Fund’s performance to that of the MSCI EAFE Index. To the extent that dividends and distributions have been paid by the Fund, the performance information for the Fund in the chart and table assumes reinvestment of the dividends and distributions. As with all such investments, past performance (before and after taxes) is not an indication of future results. The table includes all applicable fees. If BlackRock and its affiliates had not waived or reimbursed certain Fund expenses during these periods, the Fund’s returns would have been lower. Updated information on the Fund’s performance, including its current net asset value, can be obtained by visiting www.blackrock.com/funds or can be obtained by phone at (800) 882-0052.

Class K Shares
ANNUAL TOTAL RETURNS
International Index Fund
As of 12/31

During the ten-year period shown in the bar chart, the highest return for a quarter was 25.29% (quarter ended June 30, 2009) and the lowest return for a quarter was -20.05% (quarter ended September 30, 2011). The year-to-date return as of June 30, 2016 was -3.39%.

As of 12/31/15
Average Annual Total Returns

Average Annual Total Returns - Class K - BlackRock International Index Fund	1 Year	5 Years	10 Years
Class K Shares	(0.81%)	3.27%	2.68%
Class K Shares | Return After Taxes on Distributions	(1.11%)	2.60%	1.73%
Class K Shares | Return After Taxes on Distributions and Sale of Fund Shares	0.26%	2.42%	1.84%
MSCI EAFE Index (Europe, Australasia, Far East) (Reflects no deduction for fees, expenses or taxes)	(0.81%)	3.60%	3.03%

After-tax returns are calculated using the historical highest individual Federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.

[1] Other Expenses have been restated to reflect current fees.

[2] The Total Annual Fund Operating Expenses do not correlate to the ratios of expenses to average net assets given in the Fund's most recent annual report, which do not include the restatement of Other Expenses to reflect current fees.

[3] As described in the "Management of the Funds" section of the Fund's prospectus beginning on page 28, BlackRock Advisors, LLC ("BlackRock") has contractually agreed to waive and/or reimburse fees and/or expenses in order to limit Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements of International Index Fund (excluding Dividend Expense, Interest Expense, Acquired Fund Fees and Expenses and certain other Fund expenses) as a percentage of average daily net assets to 0.07% for Class K Shares, through April 30, 2018. This agreement may be terminated upon 90 days' notice by a majority of the non-interested directors of the Corporation or by a vote of a majority of the outstanding voting securities of the Fund.