Money market funds pay interest once a month, even though they accrue it every single day. Most funds sweep the accumulated daily earnings into a single dividend deposited on the last business day of the calendar month or the first business day of the following month. That gap between daily accrual and monthly payment is why your account can look flat for weeks after you buy in, then jump on a single day.
Why You Don’t See Interest Every Day
A money market fund earns income from the short-term debt it holds, and that income is divided among shareholders each day. The fund manager takes the portfolio’s total net income for the day, subtracts operating expenses, and divides the result by outstanding shares. That’s your daily dividend rate. It’s tiny on any given day, but it compounds across the month into the yield you actually see.
Accrual happens on every calendar day, not just trading days. On a Saturday, a federal holiday, or a market closure, the Treasury bills, commercial paper, and other short-term instruments in the portfolio keep generating income. Your account won’t show a visible deposit each day, but the fund’s internal accounting tracks every fraction of a cent owed to you.
Expense ratios come out before you see any earnings. The asset-weighted average expense ratio for money market funds is around 0.22%, with the range running from roughly 0.11% at the low end to about 0.73% at the high end. A fund with a gross portfolio yield of 4.00% and a 0.30% expense ratio passes through about 3.70% to shareholders.
Your daily rate won’t be identical from one day to the next either, even without a Federal Reserve move. The portfolio constantly turns over as short-term instruments mature and new ones are purchased. Changes in credit spreads, shifts in demand for commercial paper, and the specific maturity dates of holdings all nudge the daily rate up or down.
When the Monthly Payment Actually Lands
Most fund companies aggregate each day’s accrued dividends and release them as a single payment on the final business day of the calendar month. Some firms pay on the first business day of the next month instead, and a handful use a mid-month cycle. Your brokerage’s fund prospectus or account agreement spells out which schedule applies to the specific fund you hold.
Two dates control the process. The record date determines who qualifies for the payment; you need to own shares on that date to receive the dividend. The payable date is when the brokerage actually updates your balance. For money market funds, these dates are usually the same day or one day apart, so the lag is minimal compared to stock dividends.
When Interest Starts and Stops
Interest doesn’t begin the instant you click “buy.” It starts on the settlement date, which is when your cash actually enters the fund. For most money market funds, settlement happens the same day you place your order, provided you submit it before the fund’s daily cutoff (typically 4:00 p.m. Eastern). Orders placed after the cutoff generally settle the next business day. SEC Rule 15c6-1 sets the outer boundary at one business day after the trade date for most securities, but money market funds routinely settle faster than that ceiling allows.1eCFR. 17 CFR 240.15c6-1 – Settlement Cycle
On the way out, interest typically stops accruing on the day the fund processes your sell order. Redeem on a Wednesday and your cash settles that same day, you earn interest through Wednesday. The practical effect is that money market funds keep your capital productive right up until you pull it out.
One timing wrinkle catches people who plan around month-end: if you sell partway through the month, you may not receive the full accrued dividend until the fund’s next scheduled distribution date, depending on how the fund handles partial-month redemptions. The daily accrual is credited to you, but the payout still follows the monthly calendar.
Where the Payment Goes When It Arrives
When the monthly distribution hits, it goes one of two places depending on your account settings. Most brokerage accounts default to automatic reinvestment, which uses the dividend to buy additional shares at the fund’s stable price. Compounding does its work here: each new share starts accruing interest immediately, so next month’s payout is calculated on a slightly larger base.
Fractional shares participate in accrual on the same daily schedule as whole shares. If a reinvested dividend buys you 2.47 shares, all 2.47 shares earn interest the next day. There’s no rounding penalty or waiting period for partial shares.
The alternative is routing distributions to a linked bank account or a brokerage sweep account as cash. This makes sense if you’re using the income to cover regular expenses or want to redeploy the earnings elsewhere. Switching between reinvestment and cash payout is usually a one-click change in your account settings and takes effect for the next scheduled distribution.
How the Payment Is Taxed
The IRS treats money market fund distributions as dividends, not interest, even though the underlying income comes from debt instruments. You report them as ordinary dividends on your tax return, and they’re taxed at your regular income tax rate.2Internal Revenue Service. Publication 550 (2025), Investment Income and Expenses Your fund company sends a Form 1099-DIV after year-end showing the total dividends paid, including any amounts that were automatically reinvested.3Internal Revenue Service. Instructions for Form 1099-DIV (01/2024) Reinvested dividends are taxable in the year they’re paid whether you took the cash or not.
Municipal money market funds are the exception. These invest in short-term state and local government obligations, and the interest passed through is generally exempt from federal income tax under the same provision that exempts municipal bond interest.4Office of the Law Revision Counsel. 26 U.S. Code 103 – Interest on State and Local Bonds If the fund invests in obligations from your home state, the dividends may also be exempt from state income tax. Municipal money market funds typically pay less than their taxable counterparts, so the tax benefit only helps if your marginal rate is high enough to make the after-tax math work in your favor.
Treasury and government money market funds sit in the middle. Their dividends are fully subject to federal income tax, but many states exempt the portion of income derived from direct U.S. government obligations. Some states only grant this exemption if the fund holds a minimum percentage of government securities, often 50% or more, at the end of each quarter. Check your state’s specific rules before assuming the exemption applies.
Not the Same as a Bank Money Market Account
One distinction is worth flagging because it changes what “interest” even means. A money market fund at a brokerage is not the same product as a money market deposit account at a bank. Bank money market accounts pay interest under the terms of a deposit contract and carry FDIC insurance up to $250,000. Money market funds pay dividends from portfolio income and carry no FDIC insurance. The stable $1.00 share price is a goal, not a guarantee.
Money market fund shares are covered by SIPC if your brokerage firm fails, up to $500,000 in total securities protection with a $250,000 limit for cash.5SIPC. What SIPC Protects SIPC protects against broker-dealer insolvency, not against investment losses in the fund itself.