Yes, you pay federal income tax on money market account interest, and it is taxed as ordinary income at the same rates as your wages — anywhere from 10% to 37% for 2026, depending on your filing status and total income.1Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026, Including Amendments from the One, Big, Beautiful Bill State income tax may apply on top, adding up to 13.3% more depending on where you live. The picture changes if the account is held inside a retirement plan or if you own a tax-exempt municipal money market fund.
How a Bank Money Market Account Is Taxed
Banks and credit unions pay interest on money market deposit accounts, and Treasury regulations confirm that interest credited to your account is fully taxable.2eCFR. 26 CFR 1.61-7 That interest is taxed as ordinary income, not at the lower long-term capital gains rate.
Only the interest is taxable — not your balance. Deposit $10,000 and earn $400 during the year, and the $400 is what you owe tax on. Your rate depends on where that $400 lands on top of your other income. A single filer earning $60,000 in wages, for example, would see their money market interest taxed at the 22% bracket.1Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026, Including Amendments from the One, Big, Beautiful Bill
Timing is simple. You owe the tax for the year the interest is credited, whether or not you withdraw it. Interest that compounds inside the account is still taxable in the year it posts.
Money Market Mutual Funds Pay Ordinary Dividends
Money market mutual funds sit in brokerage accounts and work differently from bank deposits. They invest in short-term debt like Treasury bills and commercial paper and distribute the earnings to shareholders. Those payouts function like interest, but the IRS classifies them as ordinary dividends.3Internal Revenue Service. Topic No. 404, Dividends and Other Corporate Distributions
Ordinary dividends do not qualify for the lower rates that apply to “qualified dividends” from long-held stocks. They are taxed at your regular marginal rate, just like bank interest. That is true even if the fund automatically reinvests the dividends into more shares — you still owe tax for the year they are credited.
Municipal (Tax-Exempt) Money Market Funds
Municipal money market funds invest in short-term debt issued by state and local governments. The interest is generally exempt from federal income tax, which is why they appeal to investors in higher brackets. If the fund holds bonds from your home state, the income may also be exempt from your state’s income tax.
A few things still cost you. Capital gains realized inside the fund remain taxable. Some municipal funds hold private activity bonds, and interest from those counts as a preference item for the Alternative Minimum Tax; the fund reports any such interest in box 13 of Form 1099-DIV, which you carry to Form 6251 if the AMT applies to you.4Internal Revenue Service. 2025 Instructions for Form 6251
You must still report tax-exempt interest on line 2a of Form 1040 even though it is not taxed.5Internal Revenue Service. Instructions for Schedule B (Form 1040) The IRS uses the figure elsewhere. In particular, tax-exempt interest counts in the “combined income” formula that decides whether your Social Security benefits are taxable. If one-half of your benefits plus your other income (including tax-exempt interest) exceeds $25,000 for single filers or $32,000 for joint filers, part of your benefits becomes taxable.6Internal Revenue Service. Social Security Income
Money Market Holdings Inside a Retirement Account
Holding a money market fund inside a tax-advantaged retirement account changes the tax picture entirely. The account type controls when — or whether — you ever pay tax on the earnings.
In a traditional IRA or 401(k), interest and dividends earned inside the account are not taxed in the year they post. You defer the tax, and the whole distribution is taxed as ordinary income when you take it out, typically in retirement.7Internal Revenue Service. Traditional IRAs
In a Roth IRA or Roth 401(k), you contribute after-tax dollars, and all growth accumulates tax-free. Qualified distributions — generally after age 59½ and at least five years after your first contribution — come out completely tax-free.8Internal Revenue Service. Roth IRAs
Either way, the money market earnings do not generate a 1099-INT or 1099-DIV each year. Taxes only enter the picture when you take a distribution. If you are parking cash for safety and liquidity and can do it inside a Roth, the tax on the earnings goes to zero.
State Tax and the 3.8% Surtax for Higher Earners
Most states with an income tax treat money market interest and dividends as ordinary taxable income, just as the federal government does. State rates range from 0% in the eight states with no individual income tax up to 13.3% at the top bracket in the highest-tax state.
If you own a municipal money market fund, check where the underlying bonds were issued. Interest from in-state municipal bonds is typically exempt from both federal and state income tax, while out-of-state municipal interest can still be taxed by your home state even though it is federally exempt.
High earners face an additional 3.8% net investment income tax (NIIT) on top of regular income tax. It kicks in when modified adjusted gross income exceeds $200,000 for single filers, $250,000 for joint filers, or $125,000 for married filing separately.9Office of the Law Revision Counsel. 26 USC 1411 – Imposition of Tax These thresholds are not indexed to inflation. Bank money market interest and ordinary dividends from money market mutual funds both count as net investment income; tax-exempt municipal interest does not.10Internal Revenue Service. Topic No. 559, Net Investment Income Tax For someone at the top of both, the effective federal rate on money market earnings can reach 40.8% before state tax.
What You Receive and What You Report
Your bank or brokerage sends the appropriate tax form early each year, usually by mid-February. Form 1099-INT reports interest from bank and credit union money market deposit accounts; institutions must send it if they paid you at least $10 in interest for the year.11Internal Revenue Service. About Form 1099-INT, Interest Income Form 1099-DIV reports dividends from money market mutual funds, with total ordinary dividends in box 1a and any tax-exempt interest dividends in box 12.12Internal Revenue Service. Instructions for Form 1099-DIV
If your earnings fall below $10 and no form arrives, you still have to report the income.13Internal Revenue Service. Topic No. 403, Interest Received Keep your own records so you can report accurately either way.
On Form 1040, bank interest goes on the taxable interest line, mutual fund distributions on the ordinary dividends line, and tax-exempt interest on line 2a. If your total taxable interest or total ordinary dividends exceed $1,500 for the year, you also complete Schedule B, listing each payer.14Internal Revenue Service. About Schedule B (Form 1040), Interest and Ordinary Dividends
Estimated Quarterly Payments
Money market interest and dividends generally have no tax withheld at the source. If your investment income will push what you owe at filing time to $1,000 or more, the IRS expects estimated quarterly tax payments through the year.15Internal Revenue Service. Estimated Taxes You can generally sidestep an underpayment penalty by paying at least 90% of your current-year tax or 100% of the prior year’s, whichever is smaller. Payments are due in April, June, September, and January.
A modest amount of interest offset by ample paycheck or pension withholding may not require any estimated payments at all. Retirees and self-employed taxpayers who lean on investment income are the ones most likely to need them.
Foreign Money Market Accounts
A money market account at a foreign financial institution triggers a separate obligation. When the combined value of all your foreign financial accounts tops $10,000 at any point in the calendar year, you must file a Report of Foreign Bank and Financial Accounts (FBAR) with the Financial Crimes Enforcement Network by April 15 of the following year.16Financial Crimes Enforcement Network. Report Foreign Bank and Financial Accounts The interest itself is still taxable on your federal return, and FBAR penalties can be severe even when no additional tax is owed on the income.