Class A Prospectus | SIIT LARGE CAP INDEX FUND

SIIT LARGE CAP INDEX FUND

Investment Goal

Investment results that correspond to the aggregate price and dividend performance of the securities in the Russell 1000 Index.

Fees and Expenses

This table describes the fees and expenses that you may pay if you buy and hold Fund shares.

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Class A Prospectus SIIT LARGE CAP INDEX FUND SIIT LARGE CAP INDEX FUND - CLASS A
Management Fees		0.17%
Distribution (12b-1) Fees		none
Other Expenses		0.06%
Acquired Fund Fees and Expenses (AFFE)		0.01%
Total Annual Fund Operating Expenses	[1]	0.24%

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 and returns may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Class A Prospectus SIIT LARGE CAP INDEX FUND SIIT LARGE CAP INDEX FUND - CLASS A	25	77	135	306

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual Fund operating expenses or in the Example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 14% of the average value of its portfolio.

Principal Investment Strategies

The Large Cap Index Fund invests substantially all of its assets (at least 80%) in securities listed in the Russell 1000 Index. The Russell 1000 Index measures the performance of the large-cap segment of the U.S. equity universe and includes approximately 1000 of the largest securities based on a combination of their market cap and current index membership. The Fund generally gives the same weight to a given stock as the Russell 1000 Index does.

In seeking to replicate the performance of the Russell 1000 Index, the Fund may invest, to a lesser extent, in American depositary receipts (ADRs). The Fund may also invest in securities of companies located in developed foreign countries and securities of small capitalization companies. The Fund's ability to replicate the performance of the Russell 1000 Index will depend to some extent on the size and timing of cash flows into and out of the Fund, as well as on the level of the Fund's expenses. The Sub-Adviser selects the Fund's securities under the general supervision of SIMC, but the Sub-Adviser makes no attempt to "manage" the Fund in the traditional sense (i.e., by using economic, market or financial analyses). Instead, the Sub-Adviser purchases a basket of securities that includes a representative sample of the companies in the Russell 1000 Index. However, the Fund's Sub-Adviser may, but is not required to, sell an investment if the merit of the investment has been substantially impaired by extraordinary events, such as fraud or a material adverse change in an issuer, or adverse financial conditions.

Principal Risks

Depositary Receipts Risk — Depositary receipts, such as ADRs, are certificates evidencing ownership of shares of a foreign issuer that are issued by depositary banks and generally trade on an established market. Depositary receipts are subject to many of the risks associated with investing directly in foreign securities, including, among other things, political, social and economic developments abroad, currency movements and different legal, regulatory and tax environments.

Equity Market Risk — The risk that stock prices will fall over short or extended periods of time.

Foreign Investment Risk — The risk that securities may be subject to additional risks due to, among other things, political, social and economic developments abroad, currency movements and different legal, regulatory and tax environments.

Investment Style Risk — The risk that its investment approach, which attempts to replicate the performance of the Russell 1000 Index, may underperform other segments of the equity markets or the equity markets as a whole. The Fund is also subject to the risk that large capitalization securities may underperform other segments of the equity markets or the equity markets as a whole.

Liquidity Risk — The risk that certain securities may be difficult or impossible to sell at the time and the price that the Fund would like. The Fund may have to lower the price, sell other securities instead or forego an investment opportunity, any of which could have a negative effect on Fund management or performance.

Sampling Risk — The Fund may not fully replicate the benchmark index and may hold securities not included in the index. As a result, the Fund may not track the return of its benchmark index as well as it would have if the Fund purchased all of the securities in its benchmark index.

Small Capitalization Risk — Smaller capitalization companies in which the Fund invests may be more vulnerable to adverse business or economic events than larger, more established companies. In particular, small capitalization companies may have limited product lines, markets and financial resources and may depend upon a relatively small management group. Therefore, small capitalization stocks may be more volatile than those of larger companies. Small capitalization stocks may be traded over-the-counter or listed on an exchange.

Tracking Error Risk — The risk that the Fund's performance may vary substantially from the performance of the benchmark index it tracks as a result of cash flows, Fund expenses, imperfect correlation between the Fund's and benchmark's investments and other factors.

Loss of money is a risk of investing in the Fund.

Performance Information

The bar chart and the performance table below provide some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year for the past ten years, and by showing how the Fund's average annual returns for 1, 5 and 10 years, and since the Fund's inception compare with those of a broad measure of market performance. The performance information shown is based on full calendar years. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. For current performance information, please call 1-800-DIAL-SEI.

Best Quarter: 16.46% (06/30/09)

Worst Quarter: -22.51% (12/31/08)

The Fund's total return from January 1, 2013 to June 30, 2013 was 13.94%.

Average Annual Total Returns (for the periods ended December 31, 2012)

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. Your actual after-tax returns will depend on your tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.

Average Annual Returns Class A Prospectus SIIT LARGE CAP INDEX FUND	Label	Average Annual Returns, 1 Year	Average Annual Returns, 5 Years	Average Annual Returns, 10 Years	Average Annual Returns, Since Inception		Average Annual Returns, Inception Date
SIIT LARGE CAP INDEX FUND - CLASS A	Return Before Taxes	16.32%	1.88%	7.44%	4.44%	[1]	Apr. 01, 2002
After Taxes on Distributions SIIT LARGE CAP INDEX FUND - CLASS A	Return After Taxes on Distributions	15.68%	1.43%	6.96%	3.96%	[1]
After Taxes on Distributions and Sale of Fund Shares SIIT LARGE CAP INDEX FUND - CLASS A	Return After Taxes on Distributions and Sale of Fund Shares	11.18%	1.45%	6.14%	3.45%	[1]
Russell 1000 Index Return (reflects no deduction for fees, expenses or taxes)	Russell 1000 Index Return (reflects no deduction for fees, expenses or taxes)	16.42%	1.92%	7.52%	5.12%	[1]	Apr. 30, 2002

[1] Because the Fund incurred AFFE during the most recent fiscal year, the operating expenses in this fee table will not correlate to the expense ratio in the Fund's financial statements (or the "Financial Highlights" section in the prospectus) because the financial statements include only the direct operating expenses incurred by the Fund, not the indirect costs of investing in other investment companies.

[1] Index returns are shown from April 30, 2002.