How to Compare HYSA vs Money Market Fund vs Treasury Bills for Your Emergency Fund in 2026
Choosing where to keep an emergency fund is more complicated when several low-risk options offer competitive yields. As of August 2026, some widely available high-yield savings accounts, or HYSAs, advertise annual percentage yields around 4.20% to 4.50%. Certain niche savings offers advertise even higher rates, but those promotions may apply only to small balances or require direct deposits, membership, or other conditions.
Money market deposit accounts have also promoted rates near 5.00%, but they should not be confused with money market mutual funds. Major money market funds have recently reported seven-day SEC yields closer to approximately 3.62% to 3.68%. Short-term Treasury bill yields have generally been around 3.79% to 4.01%, depending on maturity and market conditions.
The highest advertised number should not determine where you keep emergency savings. Access time, federal protection, taxes, fees, account requirements, and rate stability can matter more than a small difference in yield.
Rates and economic conditions can change quickly. Verify the current APY, seven-day SEC yield, Treasury auction rate, account requirements, and transfer rules before moving money. This article provides general educational information, not personalized financial, tax, or legal advice.
Quick Comparison: Which Emergency-Fund Option Fits You?
| Feature | High-Yield Savings Account | Money Market Fund | Treasury Bill |
|---|---|---|---|
| Indicative August 2026 yield | Competitive offers around 4.20%–4.50% APY; conditions may apply | Some major funds around 3.62%–3.68% seven-day SEC yield | Approximately 3.79%–4.01% for shorter maturities |
| Access | Immediate to several business days, depending on transfer method | Often same day or next business day within a brokerage; bank transfers may take longer | At maturity, or earlier by selling through a brokerage |
| Protection | FDIC insurance at eligible banks | Not FDIC-insured; eligible brokerage assets may receive SIPC protection | Backed by the full faith and credit of the U.S. government |
| State and local taxes | Interest is generally taxable | Depends on the fund’s holdings and applicable state rules | Interest is generally exempt |
| Rate behavior | Variable APY | Variable seven-day yield | Yield is locked in when purchased and held to maturity |
| Typical minimum | Often $0, although provider rules vary | Often low or no minimum, but some funds require more | $100 through TreasuryDirect |
| Best fit | Immediate-access emergency savings | Reserves already held at a brokerage | Later emergency-fund tiers that can be laddered |
For most households, an HYSA is the simplest starting point because emergencies rarely arrive on a convenient maturity date. A money market fund can be useful when cash is already at a brokerage and the account provides reliable withdrawal features. T-bills can fit the portion of a larger reserve that is unlikely to be needed immediately.
Be careful with similar terminology. A money market fund is a mutual fund sold through a brokerage or fund company. A money market deposit account is a bank deposit account and may qualify for FDIC insurance. An advertisement for a money market account paying close to 5.00% does not necessarily describe a money market mutual fund.
High-Yield Savings Accounts: Best for Immediate Access
An HYSA is an interest-bearing deposit account offered by a bank or credit union. Online banks frequently pay higher rates than traditional savings accounts because they may have lower operating costs or use attractive rates to compete for deposits.
As of August 2026, some competitive HYSAs advertise approximately 4.20% to 4.50% APY. Some specialized promotions advertise higher rates, but they may cap the qualifying balance, require recurring deposits, or impose other eligibility conditions. Compare the rate that would apply to your full emergency-fund balance rather than relying on the headline alone.
APY incorporates compounding over a year, which makes it useful for comparing deposit accounts under similar balance and withdrawal assumptions. It does not lock in the rate for a year.
Liquidity and transfer timing
HYSA funds are generally liquid, but “available for withdrawal” does not necessarily mean “available in your checking account today.” External transfers commonly take one to two business days and can take longer for new accounts, large transfers, weekends, or bank holidays.
Some banks provide an ATM card, wire transfers, or immediate transfers to an affiliated checking account. Others require an external ACH transfer. Although the former federal six-withdrawal limit for savings accounts is no longer mandatory, an individual institution may still impose transaction limits or fees.
Before selecting an HYSA, check:
- How long transfers to your primary checking account usually take.
- Whether ATM, debit-card, wire, or same-bank transfer access is available.
- Whether the advertised APY applies to the entire balance.
- Whether direct deposit, membership, or a minimum balance is required.
- Whether the rate is introductory or available only to new customers.
- Whether monthly maintenance, minimum-balance, wire, or transaction fees apply.
FDIC and credit-union insurance
At an FDIC-insured bank, eligible deposits are generally insured up to $250,000 per depositor, per insured bank, per ownership category. Federally insured credit unions provide comparable protection through the National Credit Union Share Insurance Fund.
Insurance limits apply across eligible accounts held at the same institution within the same ownership category. Opening two savings accounts at one bank does not automatically double your coverage. If you use a financial technology app, confirm which bank actually holds the deposits and how pass-through insurance requirements are handled.
The main HYSA trade-off
HYSA rates are variable. A bank may lower its APY when market rates fall, and a promotional rate may expire. That uncertainty is usually acceptable for the first tier of an emergency fund because dependable access often matters more than locking in a yield.
Money Market Funds: Brokerage Convenience with Different Protection
A money market fund is a mutual fund that invests in short-term, high-quality debt. Depending on the fund, its holdings may include Treasury bills, government agency securities, repurchase agreements, certificates of deposit, commercial paper, or other short-term obligations.
Money market funds generally seek to maintain a stable net asset value of $1 per share. That objective is not a guarantee, however, and a fund can lose value.
Seven-day yield versus HYSA APY
Money market funds commonly publish a seven-day SEC yield. This annualized measure reflects the fund’s recent income after fund expenses. It is not a promise that the investor will earn the same rate for the next year.
Recent August 2026 figures for some Vanguard money market funds have placed seven-day SEC yields around 3.62% to 3.68%. That is below many competitive HYSAs advertising 4.20% to 4.50% APY. Money market funds and HYSAs both respond to short-term interest rates, but they should not be assumed to offer equivalent yields at any particular time.
An HYSA’s APY and a fund’s seven-day SEC yield are also calculated differently. Use them as comparison tools, but examine the actual dollar return, expenses, conditions, and tax treatment before deciding.
SIPC is not FDIC insurance
Money market mutual funds are not FDIC-insured. At a SIPC-member brokerage, eligible securities may be protected if the brokerage fails and customer assets are missing. Standard SIPC protection is generally limited to $500,000 per customer, including a $250,000 limit for cash claims.
SIPC does not reimburse investors because a fund declines in value, performs poorly, or fails to maintain its targeted $1 share price. It addresses certain brokerage-custody failures, not ordinary investment losses.
Access, expenses, and operational details
Some brokerages automatically sell money market fund shares to cover withdrawals, checks, debit-card purchases, or securities trades. Others require the investor to place a sell order and wait for settlement. Moving the proceeds to an outside bank may add another business day or more.
Review the fund’s:
- Seven-day SEC yield and expense ratio.
- Minimum initial and ongoing investment.
- Settlement and transaction cutoff times.
- Automatic-redemption or cash-sweep features.
- Check-writing, debit-card, and bill-payment options.
- Redemption restrictions and separate brokerage fees.
A government or Treasury money market fund may produce income that qualifies for state tax relief, but the result depends on its holdings and state law. Income attributable to repurchase agreements may not receive the same treatment as income directly attributable to U.S. Treasury obligations.
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Treasury Bills: Tax Advantages and Maturity Constraints
Treasury bills are short-term obligations of the U.S. government, commonly issued with maturities ranging from 4 to 52 weeks. Investors generally purchase a bill at a discount and receive its face value at maturity. The difference is the interest earned.
Shorter-maturity T-bill yields during 2026 have generally been around 3.79% to 4.01%, although auction results and secondary-market prices change continually. Unlike an HYSA or money market fund rate, the return on a particular T-bill is set at purchase if the bill is held to maturity.
State and local tax advantages
T-bill interest is subject to federal income tax but is generally exempt from state and local income taxes. That exemption can make a T-bill competitive with a higher-yielding HYSA for residents of states such as California, New York, or New Jersey.
The benefit is smaller or nonexistent for residents of states without an individual income tax. Tax results depend on personal circumstances and state-specific rules, so use your actual marginal rates or consult a qualified tax professional.
Buying and reinvesting T-bills
Individuals can purchase T-bills through TreasuryDirect or an eligible brokerage. TreasuryDirect permits purchases in $100 increments and allows reinvestment subject to its rules. Brokerages may provide access to both new-issue auctions and secondary-market trading.
With TreasuryDirect, principal is normally returned to the linked bank account at maturity unless reinvestment is selected. A bill held there cannot simply be sold immediately. It generally must first be transferred to a bank, broker, or dealer, making TreasuryDirect a poor location for money that may be needed on short notice.
A brokerage-held bill can usually be sold before maturity, but its market price may be above or below the original purchase price. A sale may also involve a bid-ask spread or other costs. Holding the bill to maturity avoids that market-price uncertainty.
Compare After-Tax Returns, Liquidity, and Emergency Scenarios
A $20,000 after-tax example
Assume a household compares a 4.15% HYSA with a 3.90% T-bill. Although some HYSAs advertise higher rates in August 2026, 4.15% provides a conservative illustration. The household has a $20,000 emergency fund, a 22% federal marginal tax rate, and a 5% state marginal tax rate.
For simplicity, this example applies the rates directly and ignores compounding differences, deductions, credits, and state-specific tax calculations.
- HYSA: $20,000 × 4.15% produces $830 of gross annual interest. After an assumed combined 27% federal and state tax, approximately $605.90 remains.
- T-bill: $20,000 × 3.90% produces $780 of gross interest. After an assumed 22% federal tax and no state tax, approximately $608.40 remains.
Under these simplified assumptions, the T-bill produces about $2.50 more after tax despite its lower stated yield. The difference is small, demonstrating why access and account mechanics may matter more than a marginal yield advantage.
A useful shortcut is to estimate an HYSA’s state-tax-adjusted yield. At a 5% state marginal rate, a 4.15% HYSA retains approximately 3.94% before federal tax: 4.15% × (1 − 0.05). That narrowly exceeds a 3.90% T-bill before accounting for federal tax on both options. At higher state tax rates, the T-bill’s exemption becomes more valuable.
How each option handles real emergencies
- Job loss: A layered structure can work because expenses arrive over several months. Immediate cash can remain in an HYSA while later months are held in a money market fund or T-bill ladder.
- Medical bill: An HYSA or brokerage fund with reliable payment features may work when the bill is due soon but not necessarily today.
- Car repair: A checking buffer, ATM-accessible HYSA, or credit card paired with cash available before the due date can prevent a forced T-bill sale.
- Same-day cash need: A checking buffer is generally more dependable than an external HYSA, money market fund, or TreasuryDirect account.
Account for inflation
Mid-2026 inflation measures and forecasts do not support relying on a single 3.2% estimate. Recent figures and expectations have ranged from approximately 3.3% to 4.0%, including readings near 3.5% to 3.7%. The appropriate assumption depends on the inflation measure and forecast period.
If inflation averages 3.6%, a 4.15% nominal HYSA yield produces a real return of approximately 0.53% before taxes using the formula (1.0415 ÷ 1.036) − 1. A 3.90% T-bill produces a real return of approximately 0.29% before taxes. If inflation reaches 4.0%, both options would provide little or no positive real return after taxes.
Emergency savings are designed primarily to preserve liquidity and reduce the risk of borrowing at high interest rates or selling volatile investments during a downturn. Maintaining purchasing power matters, but maximizing real return is not the fund’s only purpose.
How to Build a Three-Tier Emergency-Fund Strategy
You do not need to place the entire emergency fund in one product. A three-tier structure can balance immediate access, convenience, tax efficiency, and rate stability.
Tier 1: Immediate expenses
Keep approximately one month of essential expenses in a linked HYSA and checking account. Maintain enough directly in checking to cover a same-day repair, insurance deductible, or urgent trip without waiting for a transfer.
Tier 2: Near-term reserves
Place another one or two months of expenses in a government money market fund if you already use a brokerage with convenient withdrawals. Confirm whether shares are redeemed automatically, when proceeds become available, and how long an external transfer takes.
If the fund’s yield is materially below the best HYSA available to you, brokerage convenience or tax treatment should provide a clear reason for accepting the lower rate.
Tier 3: Later-month protection
Consider a T-bill ladder for reserves unlikely to be needed immediately, such as months four through six. For example, divide $12,000 among four T-bills scheduled to mature about four weeks apart. As each bill matures, use the proceeds if needed or reinvest them at the end of the ladder.
Match maturities to possible cash needs instead of selecting the highest yield automatically. Do not count a credit-card limit as emergency savings unless liquid cash will be available to pay the balance before interest begins accruing.
Review the structure at least quarterly and check:
- Current HYSA APYs, seven-day SEC yields, and T-bill auction rates.
- Requirements attached to unusually high advertised savings rates.
- Bank deposit totals relative to FDIC or NCUA insurance limits.
- Brokerage settlement and bank-transfer procedures.
- Fund expenses and the composition of Treasury-oriented funds.
- Federal, state, and local tax treatment.
- Whether essential monthly expenses have increased.
What to Do Next
- Calculate three to six months of essential expenses, including housing, food, utilities, insurance, transportation, minimum debt payments, and necessary medical costs.
- Decide how much must be available the same day, within two business days, and within one to three months.
- Confirm each provider’s current APY or yield, fees, minimums, insurance status, balance caps, withdrawal rules, and transfer timing.
- Estimate after-tax returns using your federal and state marginal tax rates instead of comparing headline yields alone.
- Keep the first tier highly liquid, then use a money market fund or T-bill ladder only for reserves that can tolerate additional steps or delays.
- Test your setup before an emergency by making a small withdrawal or transfer and recording how long it takes.
- Reassess the allocation when interest rates, income, expenses, family obligations, or tax residency changes.
The practical answer to the HYSA versus money market fund versus Treasury bill comparison is often a combination. An HYSA is usually the strongest foundation for immediate emergencies. A money market fund can simplify management of cash already held at a brokerage, although its yield and protection differ from those of a bank account. T-bills can provide state-tax advantages and a fixed return for later emergency-fund tiers.
The best structure is not necessarily the one with the highest advertised rate. It is the one that keeps enough money accessible when an emergency occurs while earning a reasonable return on cash that can wait.
