Fund Description: iShares iBonds Sep 2018 Term Muni Bond ETF, formerly iShares iBonds Sep 2018 AMT-Free Muni Bond ETF, formerly iShares 2018 AMT-Free Muni Term ETF, formerly iShares 2018 S&P AMT-Free Municipal Series, is an exchange-traded index fund or Index ETF which is a separate investment portfolio of the iShares Trust, an open-end investment management company. INVESTMENT OBJECTIVE: The iShares iBonds Sep 2018 Term Muni Bond ETF seeks investment results that correspond generally to the price and yield performance, before fees and expenses, of the S&P AMT-Free Municipal Series 2018 Index. INDEX DESCRIPTION: The S&P AMT-Free Municipal Series 2018 Index measures the performance of investment-grade, non-callable U.S. municipal bonds maturing in 2018. The Index includes municipal bonds primarily from issuers that are state or local governments or agencies such that the interest on the bonds is exempt from U.S. federal income taxes and the federal alternative minimum tax (AMT). Each bond must have a rating of at least BBB- by Standard & Poor's Ratings Services, Baa3 by Moody’s Investors Service, Inc. or BBB- by Fitch Ratings, Inc. and must have a minimum maturity par amount of $2 million to be eligible for inclusion in the Index. To remain in the Index, bonds must maintain a minimum par amount greater than or equal to $2 million as of each rebalancing date. All bonds in the Index will mature after 5/31/2018 and before 9/2/2018. When a bond matures in the Index, an amount representing its value at maturity will be included in the Index throughout the remaining life of the Index, and any such amount will be assumed to earn a rate equal to the performance of the Standard & Poor's Financial Services LLC's, a subsidiary of The McGraw-Hill Companies, Inc., Weekly High Grade Index, which consists of Moody's Investment Grade-1 municipal tax-exempt notes that are not subject to federal AMT. The Index is a market value weighted index and is rebalanced after the market close on the last business day of each month. FUND STRATEGY: A passive or indexing approach is used to try to achieve the Fund's investment objective. Unlike many investment companies, the Fund does not try to beat the Index and does not seek temporary defensive positions when markets decline or appear overvalued. Indexing may eliminate the chance that the Fund will substantially outperform its Index but also may reduce some of the risks of active management, such as poor security selection. Indexing seeks to achieve lower costs and better after-tax performance by keeping portfolio turnover low in comparison to actively managed investment companies. The Fund generally invests at least 80% of its assets in the securities of its Index, except during the last months of the Fund’s operations. The Fund may invest the remainder of its assets in cash and cash equivalents including money market funds, as well as in municipal bonds not included in the Index. Representative sampling is an indexing strategy that is used which involves investing in a representative sample of securities that collectively has an investment profile similar to the Index. The Fund will generally hold municipal bond securities issued by state and local municipalities whose interest payments are exempt from U.S. federal income tax, the federal AMT and, effective beginning in 2013, a federal Medicare contribution tax of 3.8% on net investment income, including dividends, interest and capital gains. In the last months of operation, as the bonds held by the Fund mature, the proceeds will not be reinvested in bonds but instead will be held in cash and cash equivalents, including without limitation money market funds, AMT-free tax-exempt municipal notes, variable rate demand notes and obligations, tender option bonds and municipal commercial paper. These cash equivalents may not be included in the Index. By August 31, 2018, the Index is expected to consist entirely of cash carried in this manner. Around the same time, the Fund will wind up and terminate, and its net assets will be distributed to then-current shareholders. The Fund may lend securities representing up to one-third of the value of the Fund’s total assets (including the value of the collateral received). FUND MANAGEMENT: BlackRock Fund Advisors (BFA) serves as the investment adviser to the Fund.