Money market accounts vs money market funds: rates, safety and how they work

• Money market account (MMDA): a bank deposit, FDIC-insured up to $250,000 per depositor, per bank, per ownership category; national average rate 0.63% on October 19, 2026.
• Money market fund (MMF): a mutual fund holding short-term debt, not FDIC-insured; $8.02 trillion in assets on November 4, 2026, according to ICI.
• Rates track the federal funds rate (3.75% to 4% after the October 28, 2026 FOMC meeting), but they vary hugely from one bank or fund to another.
• Taxes: interest and fund dividends are taxed as ordinary income; Treasury and municipal funds can avoid state or federal income tax.

“Money market” covers two very different products, and the confusion matters: one is a bank account protected by federal deposit insurance, the other is an investment fund that can, in rare cases, lose value. Both are used to park cash you may need soon, and both pay far more than a checking account when the Fed keeps rates high. Choosing well can mean earning $400 a year instead of $63 on $10,000.

This guide explains what a money market account and a money market fund are, how their rates are set, how safe each one is, how they are taxed, how they compare with high-yield savings, CDs and Treasury bills, and how to choose one. The figures come from the FDIC, the Federal Reserve, the Investment Company Institute and the SEC.

What is a money market account?

A money market account, or money market deposit account (MMDA), is a savings account offered by banks and credit unions. It pays a variable interest rate, usually higher than a regular savings account, and often comes with limited check-writing or a debit card. Because it is a bank deposit, it is insured by the FDIC (or by the NCUA at a credit union) up to $250,000 per depositor, per insured bank, for each account ownership category.

Rates differ enormously. The FDIC's national average for money market accounts was 0.63% on October 19, 2026, while its national rate cap, the ceiling for banks that are not well capitalized, stood at 4.63%. Online banks routinely pay several times the average. On $10,000, an account at 0.63% earns $63 a year; one at 4% earns $400.

What is a money market fund?

A money market fund (MMF) is a mutual fund that invests in high-quality, very short-term debt: Treasury bills, repurchase agreements, agency debt and, for some funds, commercial paper and certificates of deposit. It aims to keep its share price at $1 and pays out the interest it earns as dividends. Brokers often use one as the default “settlement” fund where uninvested cash sits. Money market funds held $8.02 trillion on November 4, 2026, according to the Investment Company Institute.

The yield of a fund is usually quoted as the 7-day SEC yield, net of fees. For a government fund, it sits close to the federal funds rate minus the fund's expenses, so the expense ratio matters directly.

Money market account vs money market fund

How safe are money market accounts and funds?

A money market account is as safe as any insured bank deposit: within the $250,000 limit per bank and ownership category, the FDIC guarantees principal and interest, even if the bank fails. Above that limit, spreading cash across several banks keeps it covered.

A money market fund is not insured, and the SEC states clearly that it can lose money. It is, however, one of the most regulated products in the market: short maturities, high-quality issuers, and minimum liquidity. After the 2023 reforms, funds must hold at least 25% of their assets in daily liquid assets and 50% in weekly liquid assets, boards can no longer suspend redemptions, and some institutional prime and tax-exempt funds must charge a liquidity fee when redemptions surge, according to the SEC's fact sheet. The best-known failure dates from September 2008, when the Reserve Primary Fund fell below $1 a share after the collapse of Lehman Brothers. Government and Treasury funds, which hold only state debt, carry the least risk.

How money market rates move

Money market rates follow the Federal Reserve. After raising its target by a quarter point in September, the FOMC kept the federal funds rate at 3.75% to 4% on October 28, 2026. Money market funds pass rate changes on within days, because the debt they hold matures within weeks. Banks adjust money market accounts more slowly, and not always fully, which is why the national average sits far below the Fed's rate. When the Fed cuts, both fall.

How money market income is taxed

Interest from a money market account is taxed as ordinary income in the year it is credited. Dividends from a money market fund are also taxed as ordinary income, not at the lower rate for qualified dividends. Two exceptions help: income from U.S. Treasury securities is exempt from state and local income tax, so part of a Treasury or government fund's dividends may be state-tax-free depending on your state; and municipal money market funds generally pay income exempt from federal income tax, sometimes from state tax too for residents of the issuing state.

Money market vs high-yield savings, CDs and Treasury bills

For an emergency fund, an insured account keeps things simple. For larger cash balances at a broker, a government money market fund or Treasury bills often pay more, with state tax savings. A CD locks a rate if you expect the Fed to cut.

Best money market accounts and funds: how to compare

There is no single best money market account: the right one depends on your balance, how often you need the money and the fees you would pay. What you can do is judge any offer against public benchmarks. The FDIC publishes each month the national rate, the average paid by banks, and the national rate cap, the most that a bank that is not well capitalized may pay: a rate far above the first is a good rate, and the second gives an upper reference.

• Compare the rate after fees: the APY for an account, the 7-day SEC yield for a fund, which is already net of its expense ratio.
• Read the rate tiers: many accounts pay the advertised APY only above or below a given balance, or for an introductory period.
• Check the protection: FDIC or NCUA insurance for an account, up to $250,000 per depositor, per institution and per ownership category; government or Treasury holdings for a fund if safety comes first.
• Look at minimums and fees: minimum balance to open or to earn the advertised rate, monthly fees, minimum initial investment for a fund.
• Think about access: how fast you can move money out, and whether the account offers checks or a debit card.
• Mind taxes: Treasury or municipal funds can make sense in high-tax states.

Fees weigh more than they seem. On $10,000, the national rate of 0.63% earns $63 a year and a 3.5% APY earns $350. A $12 monthly maintenance fee costs $144 a year: at the national rate, it is more than the interest on any balance under about $22,900. For funds, two products with the same gross yield of 3.9% and expense ratios of 0.10% and 0.40% leave about $380 and $350 a year on $10,000.

The limits of money market products

Money market products protect cash, they do not grow it over the long run, as the guide on where to invest money explains. After inflation and tax, their real return is often close to zero, and it falls when the Fed cuts rates. Money meant for ten years or more belongs in diversified investments such as index funds, as explained in the guides on how to start investing in stocks and on the MSCI World and S&P 500 indices. The compound interest calculator shows the difference over time.

This guide is educational and is not personalized investment advice. No account or fund is recommended. Money market funds are not insured and can lose value. Rates quoted are those published in October and November 2026 and change frequently.

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