Strategy. Under normal market conditions, and as a fundamental policy, the Fund invests at least 80% of its net assets (plus borrowings for investment purposes) in securities the income from which, in the opinion of counsel to the issuer of each security, is exempt from regular federal individual and, as applicable, the Funds state income tax. The policy stated in the foregoing sentence may not be changed without shareholder approval of a majority of the Funds outstanding voting securities, as defined in the Investment Company Act of 1940, as amended (1940 Act). In complying with this 80% investment requirement, the Fund may invest in derivatives and other instruments that have economic characteristics similar to the Funds direct investments that are counted … Show more… Under normal market conditions, and as a fundamental policy, the Fund invests at least 80% of its net assets (plus borrowings for investment purposes) in securities the income from which, in the opinion of counsel to the issuer of each security, is exempt from regular federal individual and, as applicable, the Funds state income tax. The policy stated in the foregoing sentence may not be changed without shareholder approval of a majority of the Funds outstanding voting securities, as defined in the Investment Company Act of 1940, as amended (1940 Act). In complying with this 80% investment requirement, the Fund may invest in derivatives and other instruments that have economic characteristics similar to the Funds direct investments that are counted toward the 80% investment requirement. As a fundamental policy, the Fund may invest up to 20% of its net assets in securities subject to the federal alternative minimum tax (AMT). Additionally, under normal market conditions, and as a fundamental policy, the Fund invests at least 80% of its net assets (plus borrowings for investment purposes) in California municipal securities and in derivatives and other instruments that have economic characteristics similar to such securities. Municipal securities are generally issued by the state and its political subdivisions (such as cities, towns, counties, agencies and authorities) and primarily include municipal bonds (long-term (generally more than one-year) obligations), municipal notes (short-term obligations) and interests in municipal leases. Municipal securities generally are classified as general or revenue obligations. General obligations are secured by the issuers pledge of its full faith, credit and taxing power for the payment of principal and interest. Revenue obligations are bonds whose interest is payable only from the revenues derived from a particular facility or class of facilities, or a specific excise tax or other revenue source. The securities in which the Fund invests as part of the Funds 80% policy with respect to California municipal securities may also include securities issued by issuers located outside of California, such as U.S. territories, commonwealths and possessions, or their agencies, instrumentalities and authorities if the interest on such securities is not subject to California and federal income tax. These securities are California municipal securities for purposes of this prospectus. Most of the securities the Fund buys are investment-grade, although it can invest as much as 25% of its total assets in below-investment-grade securities (commonly called junk bonds). This restriction is applied at the time of purchase and the Fund may continue to hold a security whose credit rating has been downgraded or, in the case of an unrated security, after the Funds adviser, Invesco Advisers, Inc. (Invesco or the Adviser), has changed its assessment of the securitys credit quality. As a result, credit rating downgrades or other market fluctuations may cause the Funds holdings of below-investment-grade securities to exceed, at times significantly, this restriction for an extended period of time. If the Fund has more than 25% of its total assets invested in below-investment-grade securities, the Adviser will not purchase additional below-investment-grade securities until the level of holdings in those securities no longer exceeds the restriction. Investment-grade securities are: (i) securities rated BBB- or higher by S&P Global Ratings (S&P) or Baa3 or higher by Moodys Investors Service, Inc. (Moodys) or an equivalent rating by another nationally recognized statistical rating organization (NRSRO), (ii) securities with comparable short-term NRSRO ratings, or (iii) unrated securities determined by the Adviser to be of comparable quality, each at the time of purchase. While securities rated BBB+, BBB or BBB- by S&P or Baa1, Baa2 or Baa3 by Moodys are considered investment-grade, they have some speculative characteristics. If two or more nationally recognized statistical rating organizations have assigned different ratings to a security, the Adviser uses the highest rating assigned. The Fund also invests in unrated securities, in which case the Adviser internally assigns ratings to those securities, after assessing their credit quality and other factors, in investment-grade or below-investment-grade categories similar to those of nationally recognized statistical rating organizations. To the extent the Fund invests in pre-refunded municipal securities collateralized by U.S. government securities, the Fund may treat those securities as investment-grade (AAA) securities even if the issuer itself has a below-investment-grade rating. The Fund does not limit its investments to securities of a particular maturity range, and may hold both short and long-term securities. However, the Fund expects to focus on longer-term securities to seek higher yields. This portfolio strategy is subject to change. The Fund may invest in obligations that pay interest at fixed or variable rates. The Fund can invest in inverse floating rate interests (Inverse Floaters) issued in connection with municipal tender option bond (TOB) financing transactions to generate leverage for the Fund. The Fund can expose up to 20% of its total assets to the effects of leverage from its investments in Inverse Floaters. The Fund's investments in Inverse Floaters are included for purposes of the 80% policies described above. The Fund can invest in derivative instruments, including futures contracts. The Fund can use futures contracts, including interest rate futures, to reduce exposure to interest rate changes and to manage duration. The Fund can borrow money for investment-related purposes including to purchase additional securities, which is another form of leverage. Although the amount of borrowing will vary from time to time, the amount of leveraging from borrowings will not exceed one-third of the Funds total assets. The Fund may also borrow to meet redemption obligations or for temporary and emergency purposes. The Fund may invest more than 25% of its net assets in a segment of the municipal securities market with similar characteristics if the Adviser determines that the yields available from obligations in a particular segment justify the additional risks of a larger investment in such segment. The Fund may not, however, invest more than 25% of its net assets in industrial development revenue bonds issued for companies in the same industry. The Fund can invest up to 25% of its total assets in tobacco settlement revenue bonds, which make payments only from a states interest in the Master Settlement Agreement (MSA), and up to 25% of its total assets in tobacco bonds subject to a states appropriation pledge, which make payments from both MSA revenue and a states appropriation pledge. Decisions to purchase or sell securities are determined by the relative value considerations of the portfolio managers that factor in economic and credit-related fundamentals, market supply and demand, market dislocations and situation-specific opportunities. The purchase or sale of securities may be related to a decision to alter the Fund's macro risk exposure (such as duration, yield curve positioning and sector exposure), a need to limit or reduce the Fund's exposure to a particular security or issuer, degradation of an issuer's credit quality, or general liquidity needs of the Fund. The potential for realization of capital gains or losses resulting from possible changes in interest rates will not be a major consideration and frequency of portfolio turnover generally will not be a limiting factor if the Adviser considers it advantageous to purchase or sell securities. Show less