Class A Prospectus | SIIT LARGE CAP DIVERSIFIED ALPHA FUND

SIIT LARGE CAP DIVERSIFIED ALPHA FUND

Investment Goal

Long-term growth of capital and income.

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 DIVERSIFIED ALPHA FUND SIIT LARGE CAP DIVERSIFIED ALPHA FUND - CLASS A
Management Fees		0.40%
Distribution (12b-1) Fees		none
Other Expenses		0.06%
Acquired Fund Fees and Expenses (AFFE)		0.01%
Total Annual Fund Operating Expenses	[1]	0.47%

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 DIVERSIFIED ALPHA FUND SIIT LARGE CAP DIVERSIFIED ALPHA FUND - CLASS A	48	151	263	591

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 82% of the average value of its portfolio.

Principal Investment Strategies

Under normal circumstances, the Large Cap Diversified Alpha Fund will invest at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities of large companies. For purposes of this Fund, a large company is a company with a market capitalization in the range of companies in the Russell 1000 Index (between $1.61 billion and $424.74 billion as of July 31, 2013) at the time of purchase. The market capitalization range and the composition of the Russell 1000 Index are subject to change. The Fund may also, to a lesser extent, invest in common and preferred stocks of small capitalization companies. The Fund may also invest in ETFs based on a large capitalization index.

The Fund uses a multi-manager approach under the general supervision of SIMC. SIMC allocates most of the Fund's assets among multiple Sub-Advisers that use different investment strategies to seek to achieve returns in excess of the performance of the Russell 1000 Index. Assets of the Fund not allocated to Sub-Advisers are managed directly by SIMC. This allocation among investment strategies aims to diversify the sources from which the Fund seeks to achieve excess returns (i.e., returns in excess of a benchmark index or "alpha"), thereby diversifying the relative risk of the Fund. While the Fund is expected to have an absolute return and risk profile similar to the broad U.S. large capitalization equity market, returns may be derived in part from investing up to 20% of the Fund in securities outside of the large capitalization market.

Certain Sub-Advisers use portfolio strategies that are designed to correlate with a portfolio of large capitalization equity securities, but which are composed of futures contracts (also called "futures") and swaps backed by other types of securities. The Fund may invest in futures and swaps either for risk management purposes or as part of its investment strategies. These portfolio strategies are included in the Fund's principal investment strategy described above. The managers may purchase futures contracts or swaps, generally using only a fraction of the assets that would be needed to purchase the equity securities directly, so that the remainder of the assets in a portfolio may be invested in other types of securities. Therefore, a Sub-Adviser would seek to outperform a large capitalization benchmark by purchasing futures contracts or swaps correlated to a broad large capitalization index and investing the remaining assets in other types of securities to add excess return. This portion of the Fund's assets may be invested in a wide range of asset classes other than large capitalization equities.

The Fund may also invest in futures contracts and swaps for speculative or hedging purposes. Futures and swaps are used to synthetically obtain exposure to securities or baskets of securities. These derivatives are also used to mitigate the Fund's overall level of risk and/or the Fund's risk to particular types of securities or market segments. In addition to the obtaining synthetic exposure and mitigating risk, interest rate swaps, in particular, are also used to manage the Fund's yield spread sensitivity. In other words, by entering into interest rate swaps, the Fund can hedge the risk associated with its current investments in fixed income assets in response to changes in interest rates. When the Fund seeks to take an active long or short position with respect to the likelihood of an event of default of a security or basket of securities, the Fund may use credit default swaps. The Fund may buy credit default swaps in an attempt to manage credit risk where the Fund has credit exposure to an issuer and the Fund may sell credit default swaps to more efficiently gain credit exposure to such security or basket of securities.

Principal Risks

Credit Risk — The risk that the issuer of a security or the counterparty to a contract will default or otherwise become unable to honor a financial obligation.

Derivatives Risk — The Fund's use of futures and swaps is subject to market risk, leverage risk, correlation risk and liquidity risk. Leverage risk and liquidity risk are described below. Market risk is the risk that the market value of an investment may move up and down, sometimes rapidly and unpredictably. Correlation risk is the risk that changes in the value of the derivative may not correlate perfectly with the underlying asset, rate or index. The Fund's use of swap agreements is also subject to credit risk and valuation risk. Valuation risk is the risk that the derivative may be difficult to value and/or valued incorrectly. Credit risk is described above. Each of these risks could cause the Fund to lose more than the principal amount invested in a derivative instrument.

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

Exchange-Traded Funds (ETFs) Risk — The risks of owning shares of an ETF generally reflect the risks of owning the underlying securities the ETF is designed to track, although lack of liquidity in an ETF could result in its value being more volatile than the underlying portfolio securities. When the Fund invests in an ETF, in addition to directly bearing the expenses associated with its own operations, it will bear a pro rata portion of the ETF's expenses.

Investment Style Risk — The risk that large capitalization securities may underperform other segments of the equity markets or the equity markets as a whole. The Fund uses portfolio strategies that are designed to correlate with a portfolio of large capitalization equity securities, but which are composed of derivative instruments backed by other types of securities in order to seek to generate excess return. The financial performance of the Fund will be affected, positively or negatively, by the financial performance of the securities backing such derivative instruments. These factors, among others, may cause the Fund to perform differently than a fund that is invested solely in large capitalization equity securities or other funds with similar investment objectives or cause the Fund to underperform its benchmark.

Leverage Risk — The Fund's use of derivatives may result in the Fund's total investment exposure substantially exceeding the value of its portfolio securities and the Fund's investment returns depending substantially on the performance of securities that the Fund may not directly own. The use of leverage can amplify the effects of market volatility on the Fund's share price and may also cause the Fund to liquidate portfolio positions when it would not be advantageous to do so in order to satisfy its obligations. The Fund's use of leverage may result in a heightened risk of investment loss.

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.

Portfolio Turnover Risk — Due to its investment strategy, the Fund may buy and sell securities frequently. This may result in higher transaction costs and additional capital gains tax liabilities.

Small and Medium Capitalization Risk — The risk that small and medium 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 and medium capitalization companies may have limited product lines, markets and financial resources and may depend upon a relatively small management group. Therefore, small capitalization and medium capitalization stocks may be more volatile than those of larger companies. Small capitalization and medium capitalization stocks may be traded over-the-counter or listed on an exchange.

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 six years, and by showing how the Fund's average annual returns for 1 year, 5 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: 17.00% (06/30/09)

Worst Quarter: -25.55% (12/31/08)

The Fund's total return from January 1, 2013 to June 30, 2013 was 13.05%.

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 DIVERSIFIED ALPHA FUND	Label	Average Annual Returns, 1 Year	Average Annual Returns, 5 Years	Average Annual Returns, Since Inception	Average Annual Returns, Inception Date
SIIT LARGE CAP DIVERSIFIED ALPHA FUND - CLASS A	Return Before Taxes	15.97%	0.18%	2.46%	Feb. 28, 2006
After Taxes on Distributions SIIT LARGE CAP DIVERSIFIED ALPHA FUND - CLASS A	Return After Taxes on Distributions	15.52%	(0.05%)	1.98%
After Taxes on Distributions and Sale of Fund Shares SIIT LARGE CAP DIVERSIFIED ALPHA FUND - CLASS A	Return After Taxes on Distributions and Sale of Fund Shares	10.64%	0.09%	1.93%
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%	3.95%	Feb. 28, 2006

[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.