HYSA vs. Money Market Fund vs. Treasury Bills

“High yield” is a marketing description rather than a separate federal account category. At an FDIC-insured bank, eligible savings deposits receive deposit-insurance coverage within the applicable ownership-category limits; confirm the institution, ownership structure, balance, fees, withdrawal terms, and any tier requirements.

Savings accounts quote annual percentage yield, which reflects the interest rate and compounding under federal disclosure rules. For a variable-rate account, the advertised APY uses the rate in effect under the rule's assumptions and is not a promise that the rate will remain unchanged.

A money market fund is a mutual fund holding liquid, short-term debt instruments, cash, and cash equivalents. Government, prime, and tax-exempt funds can follow different rules and take different risks, so the words “money market” do not identify one uniform product.

Most retail and government money market funds seek a stable $1 net asset value, but they are not FDIC-insured bank deposits and can lose value. Compare the fund category, portfolio, fees, current yield definition, settlement, redemption access, and any applicable liquidity provisions.

TreasuryDirect currently lists regular bill terms from four through 52 weeks. Bills are sold at a discount or at face value, pay face value at maturity, and produce interest as the difference between purchase price and the maturity payment.

Bills are marketable and can be sold before maturity, but a sale price can differ from the amount paid or the face value. A bill held at TreasuryDirect may have different transfer and access mechanics from one held through a brokerage, so match the maturity and custody method to the spending date.

Bank-account interest and Treasury interest are generally subject to federal income tax. The IRS states that Treasury bill interest is exempt from state and local income taxes; money market fund tax treatment depends on the fund and its distributions, so use its tax documents rather than assuming a government-oriented name creates the same result.

APY, a money market fund yield, and a Treasury bill investment rate use different calculations and assumptions. Align the measurement date and holding period, account for fees, taxes, transfer time, maturity, early-sale risk, and deposit or investment protections before comparing them.

Write the earliest possible withdrawal date, the amount that must remain stable, and the acceptable transfer delay. Emergency cash, a tax payment due on a known date, and cash awaiting long-term investment can justify different implementations.

Then compare products using a dated worksheet. Record the institution or fund, quoted-rate label, as-of date, fees, minimums, protection, settlement, transfer path, maturity, early-sale consequences, and tax treatment.