Pioneer US Government Money Market Fund*

*You could lose money by investing in the Fund. Although the Fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The Fund’s sponsor has no legal obligation to provide financial support to the Fund, and you should not expect that the sponsor will provide financial support to the Fund at any time. The securities issued by US Government-sponsored entities (e.g., FNMA, Freddie Mac) are neither guaranteed nor issued by the US Government.

¹Weighted average maturity (WAM) - An average of the maturities of all securities held in the portfolio, weighted by each security’s percentage of net assets. When calculating WAM, money market rules permit a fund to use the interest rate reset date, rather than a security’s final maturity date, for variable and floating rate securities.

²Weighted average life (WAL) - An average of the maturities of all securities held in the portfolio, weighted by each security’s percentage of net assets, considering each security’s maturity without reference to applicable interest rate reset dates. The WAL calculation considers a security’s final maturity date.

The portfolio is actively managed, and current holdings may be different.

For fund descriptions, historical and current performance, standardized returns as of the most recent quarter-end, risk disclosure or a prospectus, please visit the performance page .

For more information about our funds, please call 1-800-225-6292 or visit our Order Literature page to request a quarterly fact sheet and prospectus.