Jul. 31, 2019

PROSPECTUS SUPPLEMENT

NORTHERN FUNDS

MONEY MARKET FUNDS

SUPPLEMENT DATED APRIL 3, 2020 TO THE SUMMARY PROSPECTUSES AND PROSPECTUS DATED JULY 31, 2019, AS SUPPLEMENTED

Effective immediately, each Fund’s Summary Prospectus and Prospectus are amended as follows.

1. In the section in each Fund’s Summary Prospectus entitled “Principal Risks,” the disclosure under “Stable NAV Risk” is moved to the top of the section.

2. The disclosure in each Fund’s Summary Prospectus entitled “Principal Risks” is revised to replace the disclosure under the heading “Interest Rate Risk” with the following.

INTEREST RATE RISK is the risk that during periods of rising interest rates, the Fund’s yield (and the market value of its securities) will tend to be lower than prevailing market rates; in periods of falling interest rates, the Fund’s yield (and the market value of its securities) will tend to be higher. Securities with longer maturities tend to be more sensitive to changes in interest rates, causing them to be more volatile than securities with shorter maturities. Securities with shorter maturities tend to provide lower returns and be less volatile than securities with longer maturities. If interest rates rise, the Fund’s yield may not increase proportionately, and the maturities of income securities that have the ability to be prepaid or called by the issuer may be extended. Changing interest rates may have unpredictable effects on the markets and the Fund’s investments. Recent and any future declines in interest rate levels could cause the Fund’s earnings to fall below the Portfolio’s expense ratio, resulting in a negative yield and a decline in the Fund’s share price. A general rise in interest rates may cause investors to move out of fixed income securities on a large scale, which could adversely affect the price and liquidity of fixed income securities and could also result in increased redemptions for the Fund. Fluctuations in interest rates may also affect the liquidity of fixed income securities and instruments held by the Fund.

3. The disclosure in each Fund’s Summary Prospectus entitled “Principal Risks” is revised to replace the disclosure under the heading “Market Risk” with the following.

MARKET RISK is the risk that the value of the Fund’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, changes in interest rates, lack of liquidity in the bond or equity markets, volatility in the equity markets, market disruptions caused by local or regional events such as war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions or other events or adverse investor sentiment or other political, regulatory, economic and social developments, and developments that impact specific economic sectors, industries or segments of the market. These risks may be magnified if certain events or developments adversely interrupt the global supply chain; in these and other circumstances, such risks might affect companies worldwide due to increasingly interconnected global economies and financial markets.