Total

SIIT LARGE CAP FUND

SIIT LARGE CAP 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	SIIT LARGE CAP FUND SIIT LARGE CAP FUND - CLASS A
Management Fees	0.40%
Distribution (12b-1) Fees	none
Other Expenses	0.07%
Total Annual Fund Operating Expenses	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	1 Year	3 Years	5 Years	10 Years
SIIT LARGE CAP FUND | SIIT LARGE CAP FUND - CLASS A | USD ($)	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 102% of the average value of its portfolio.

Principal Investment Strategies

Under normal circumstances, the Large Cap 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 $809 million and $1,042 billion (or $1.042 trillion) as of July 31, 2019) at the time of purchase. The market capitalization range and the composition of the Russell 1000 Index are subject to change. These securities may include common stocks, preferred stocks, warrants and exchange-traded funds (ETFs) and may in some instances be foreign securities or represent exposure to foreign markets. The Fund may also, to a lesser extent, invest in common and preferred stocks of small capitalization companies. The Fund uses a multi-manager approach, relying on a number of sub-advisers (each, a Sub-Adviser and collectively, the Sub-Advisers) with differing investment philosophies and strategies to manage portions of the Fund's portfolio under the general supervision of SEI Investments Management Corporation (SIMC or the Adviser). Due to its investment strategy, the Fund may buy and sell securities frequently.

Principal Risks

Market Risk — The risk that the market value of a security may move up and down, sometimes rapidly and unpredictably. Market risk may affect a single issuer, an industry, a sector or the equity market as a whole.

Large Capitalization Risk — The risk that larger, more established companies may be unable to respond quickly to new competitive challenges such as changes in technology and consumer tastes. Larger companies also may not be able to attain the high growth rates of successful smaller companies.

Investment Style Risk — The risk that large capitalization securities may underperform other segments of the equity markets or the equity markets as a whole.

Warrants Risk — Warrants are instruments that entitle the holder to buy an equity security at a specific price for a specific period of time. Warrants may be more speculative than other types of investments. The price of a warrant may be more volatile than the price of its underlying security, and a warrant may offer greater potential for capital appreciation as well as capital loss. A warrant ceases to have value if it is not exercised prior to its expiration date.

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.

Foreign Investment Risk — The risk that non-U.S. 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.

Small Capitalization Risk — Smaller capitalization companies in which the Fund may invest 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.

Derivatives Risk — The Fund's use of futures contracts is subject to leverage risk, correlation risk, liquidity risk and market 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 derivatives may also increase the amount of taxes payable by shareholders. Both U.S. and non-U.S. regulators are in the process of adopting and implementing regulations governing derivatives markets, the ultimate impact of which remains unclear.

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 of the security, sell other securities instead or forego an investment opportunity, any of which could have a negative effect on Fund management or performance.

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.

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, which may affect the Fund's performance.

Investing in the Fund involves risk, and there is no guarantee that the Fund will achieve its investment goal. You could lose money on your investment in the Fund, just as you could with other investments. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

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 calendar 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: 17.27% (6/30/09)
Worst Quarter: -14.95% (09/30/11)
The Fund's total return from January 1, 2019 to June 30, 2019 was 16.78%.

Average Annual Total Returns (for the periods ended December 31, 2018)

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. In the event of negative performance, the Fund's returns after taxes on distributions and sale of Fund shares are calculated assuming that an investor has sufficient capital gains of the same character from other investments to offset any capital losses from the sale of Fund shares. As a result, the Fund's returns after taxes on distributions and sale of Fund shares may exceed the Fund's returns before taxes and/or returns after taxes on distributions.

Average Annual Returns - SIIT LARGE CAP FUND	Label	1 Year	5 Years	10 Years	Since Inception	Inception Date
SIIT LARGE CAP FUND - CLASS A	Return Before Taxes	(6.39%)	6.49%	12.44%	7.64%	Jun. 14, 1996
After Taxes on Distributions | SIIT LARGE CAP FUND - CLASS A	Return After Taxes on Distributions	(12.59%)	2.32%	9.64%	6.05%
After Taxes on Distributions and Sale of Fund Shares | SIIT LARGE CAP FUND - CLASS A	Return After Taxes on Distributions and Sale of Fund Shares	(0.76%)	4.54%	9.94%	6.16%
Russell 1000 Index Return (reflects no deduction for fees, expenses or taxes)	Russell 1000 Index Return (reflects no deduction for fees, expenses or taxes)	(4.78%)	8.21%	13.28%	8.18%	Jun. 14, 1996