Performance data shown represents past performance and is no guarantee of future results. Past performance is net of management fees and expenses and reflects reinvested dividends and distributions. Past performance reflects the beneficial effect of any expense waivers or reimbursements, without which returns would have been lower. Investment returns and principal value will fluctuate and when redeemed may be worth more or less than their original cost. Returns for periods less than one year are not annualized. Current performance may be higher or lower and is available through the most recent month end at harborfunds.com or by calling 800-422-1050.

The current yield more closely reflects the current earnings of the Harbor Money Market Fund than the total return. Current yield is annualized and excludes gains and losses as defined by the Securities and Exchange Commission.

From time to time, certain fees and/or expenses have been voluntarily or contractually waived or reimbursed, which has resulted in higher returns. Without these waivers or reimbursements, the returns would have been lower. Voluntary waivers or reimbursements may be applied or discontinued at any time without notice. Only the Board of Trustees may modify or terminate contractual fee waivers or expense reimbursements.

You could lose money by investing in the Harbor Money Market 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 FDIC 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 the sponsor to provide financial support to the Fund at any time.

CUSIP identifiers have been provided by CUSIP Global Services, managed on behalf of the American Bankers Association by S&P Global Market Intelligence LLC, and are not for use or dissemination in a manner that would serve as a substitute for any CUSIP service. The CUSIP Database, © 2019 American Bankers Association. CUSIP is a registered trademark of the American Bankers Association.

The ICE BofAML US 3-Month Treasury Bill Index is comprised of a single U.S. Treasury Bill issue purchased at the beginning of each month and held for a full month, at which time that issue is sold and rolled into a newly selected issue. The issue selected each month is that having a maturity date closest to, but not beyond 90 days from the rebalance date.