Where should you park cash
you're not investing?
HYSA, money market fund, T-bills, CDs, I-bonds. The five safe homes for cash all pay roughly the same before tax, and all lose to inflationinflationA general increase in prices over time, meaning each dollar buys less than it did before.Full definition over time. The right one depends on when you need the money and what state you live in, not on chasing an extra tenth of a percent.
Match the vehicle to the horizon, not the headline rate. Emergency fund: HYSA or a government money-market fund. Under a year: T-bills or a short CD. One to five years: a T-bill ladder or I-bonds. Five years-plus: not cash at all. In a no-income-tax state, take the highest yield; in a high-tax state, Treasury interest wins after tax.
- The five options cluster tightly: the best widely available HYSA pays about 4.15% APYAnnual Percentage Yield (APY)The real return on savings after the bank pays interest on top of interest. A 5% APY savings account turns $1,000 into $1,050 after one year.Full definition, and government money-market funds, short T-bills, and CDs all sit in the mid-3% to low-4% range as of mid-2026. You are choosing between a 4.1% and a 3.7%, not a 4% and an 8%.
- Interest on Treasuries (T-bills, the Treasury slice of a money-market fund, I-bonds) is exempt from state and local income tax under 31 U.S.C. 3124. That exemption is worth roughly your state rate times the yield, and it flips the ranking once your state rate clears about 6%.
- FDICFederal Deposit Insurance Corporation (FDIC)The US agency that insures bank deposits up to $250,000 per depositor if a bank fails. or NCUA insures HYSAs and CDs to $250,000 per depositor. Government money-market funds are not FDIC-insured, but they hold Treasuries and repos and are SIPCSecurities Investor Protection Corporation (SIPC)A nonprofit that pays back customers up to $500,000 if a stock brokerage firm goes bankrupt and loses their shares. It protects against the firm failing, not against your investments dropping in value.-covered as securities to $500,000.
- After roughly 25% combined tax, a 4.15% yield nets about 3.1%, below headline CPIConsumer Price Index (CPI)The government's measure of how much a typical basket of consumer goods costs over time.Full definition of 4.17% (May 2026). Even the best cash is a small real loss. Cash buys safety and liquidityliquidityHow quickly and easily you can convert an asset to cash without significantly affecting its price.Full definition, never growth.
- I-bonds cap at $10,000 per person per year and lock for 12 months, with a 3-month interest penalty before year five. Use them only for money you will not touch for a year or more.
This page covers personal finance fundamentals that apply regardless of your view on Bitcoin or fiat currencyfiat currencyMoney declared legal tender by a government, not backed by a physical commodity. Its value rests on trust in the issuing government.Full definition.
Every dollar of cash has a job and a date. Money you might need this week goes in a high-yield savings account or a government money-market fund. Money with a known date under a year goes in a T-bill or a short CD that matures near it. Money for one to five years goes in a T-bill ladder or I-bonds. Money you will not touch for five-plus years should not be cash at all, because the real return on cash is roughly zero to negative after inflation. Then pick within the tier on after-tax yield: in a no-income-tax state, take the top rate; in a high-tax state, Treasury interest often wins even at a lower headline number.
The five cash vehicles, side by side
| VEHICLE | TYPICAL YIELD (MID-2026) | ACCESS | STATE TAX ON INTEREST | SAFETY | BEST FOR |
|---|---|---|---|---|---|
| Big-bank savings | ~0.01–0.40% | Instant | Taxable | FDIC $250k | Nothing. Move it. |
| HYSA | ~3.8–4.15% | Same or next day | Fully taxable | FDIC $250k | Emergency fund, everyday savings |
| Gov't money-market fund SPAXX, VMFXX, FDLXX |
~3.4–3.9% (7-day) | Same day at broker | Partly exempt (Treasury slice; FDLXX ~100%) | Not FDIC; SIPC $500k | Brokerage cash, high-tax-state savers |
| T-bills 4 to 52 weeks |
~3.7–4.0% | Hold to maturity or sell secondary | Exempt | Backed by US gov | Under-1-year money, high-tax states |
| CD / CD ladder | ~3.8–4.3% (locks the rate) | Locked; early-withdrawal penalty | Taxable | FDIC $250k | Money with a known future date |
| I-bonds | Fixed rate + inflation adj. verify×DON'T TRUST, VERIFYClaim: The I-bond composite rate is a fixed rate plus a semi-annual inflation adjustment, reset each May and November.Verify at: TreasuryDirect I-bond rates ↗The composite rate changes twice a year with CPI. | 12-mo lockup; penalty before yr 5 | Exempt (fed deferred) | Backed by US gov | 1–5yr money, inflation hedgehedgeAn investment made to offset potential losses in another position, like buying gold to protect against currency declines., ≤$10k/yr |
Yields are ranges, not quotes, and every one tracks the federal funds rate. The spreadspreadThe difference between the market price of Bitcoin and what an exchange actually charges you, a hidden cost on top of stated transaction fees.Full definition from best to worst among the four real options is under a percentage point, which is why chasing the last basis point is rarely worth the effort. Run your own after-tax and after-inflation numbers in the real return calculator and the money-market after-tax tool.
How much should sit in cash at all?
Enough to cover real emergencies and known near-term spending, and not a dollar more. The standard frame is three to six months of essential expenses in liquid cash, more if your income is variable or your job is at risk. Everything past that plus your known-date spending (a car, a down payment, a tax bill) is what these five vehicles are for.
Beyond the emergency fund and dated needs, holding cash is a drag, not a cushion. At a real return near zero, a large idle balance quietly loses purchasing powerpurchasing powerWhat a dollar can actually buy, not what the dollar number says. A 1971 dollar bought a gallon of gas. Today's dollar buys roughly a third of one. Same dollar, much less buying ability.Full definition every year. Size the buffer with the emergency fund calculator, then read cash management for the full placement framework.
HYSA or money-market fund for the emergency fund?
Both work. A high-yield savings account is FDIC-insured to $250,000 and settles to your checking in a day. A government money-market fund like SPAXX or VMFXX sits inside your brokerage, yields roughly the same, and lets you deploy into investments instantly without a transfer. The deciding factor is usually your state tax rate.
- No state income tax (TN, FL, TX, WA): the Treasury exemption is worth nothing to you. Take the higher headline yield, usually the HYSA or SPAXX.
- High state income tax (CA, NY, NJ above ~8%): a Treasury-heavy fund like FZFXX or FDLXX can beat a higher-yielding HYSA after tax. Run it at your rate in the money-market comparison tool.
- Either way: the big-bank 0.01% savings account your paycheck lands in is the one wrong answer. Moving it is the single highest-return action here.
Full ticker-by-ticker breakdown (SPAXX vs FZFXX vs FDLXX vs a top HYSA) is on cash management and the HYSA roundup.
When do T-bills or CDs beat a savings account?
When you know the date. A savings account is best when you might need the money at any moment. Once the money has a deadline, a T-bill or CD maturing near that date usually pays a bit more and, for the T-bill, escapes state tax.
- T-bills in 4-, 13-, 26-, and 52-week maturities are direct US-government debt, fully state-tax-exempt, and buyable at TreasuryDirect or any brokerage. Best for money you can leave alone until a set date.
- A CD ladder staggers maturities (say $2,000 each at 3, 6, 9, 12, and 18 months) so a rung frees up regularly while most of the money earns a locked, longer-term rate. Build one in the CD ladder tool.
- The catch: a CD charges an early-withdrawal penalty, and a T-bill sold before maturity trades at market price. Neither is your emergency fund; both are for money with a known horizon.
Mechanics, auction timing, and when I-bonds beat T-bills are covered in depth on I-bonds and T-bills.
Do I-bonds still make sense?
Only for a specific slot: money you will not touch for at least a year, ideally one to five, that you want protected against inflation. The composite rate is a fixed rate plus a semi-annual inflation adjustment, so an I-bond keeps pace with CPI by construction, and the interest is state-tax-exempt and federally deferred until you redeem.
The limits are the whole story: $10,000 per person per year, a 12-month minimum hold, and a 3-month interest penalty if you redeem before year five. When short T-bill yields exceed the I-bond composite rate, or when you might need the money inside a year, skip them. I-bonds preserve purchasing power against the official basket; they do not grow it. For why even that basket understates your real cost of living, see the problem.
Why does the best cash rate still lose money?
Because the number you see is nominal, and the number that matters is real. The best widely available savings account pays about 4.15%. Headline CPI is running 4.17% (May 2026), so before tax you are roughly breaking even. After tax on the interest, at say 25% combined, that 4.15% becomes about 3.1%, and you are underwater in real terms. That is not a bad account. It is the design of the whole tier.
Real return equals nominal yield minus inflation, then minus tax on the nominal yield. At 4.15% nominal, 4.17% inflation, and a 25% tax on the interest, your real after-tax return is roughly negative 1% per year. Widen the lens to money-supply growth, running near 5.6% year-over-year, and cash is losing ground even faster against the total pool of dollars. This is financial repression working exactly as intended: savers earn below inflation so government debt shrinks in real terms.
The takeaway is not to abandon cash. It is to hold only what safety and liquidity require, place it correctly, and stop treating the yield chase as a wealth strategy. See what your account actually earns over your horizon in the real return calculator, weigh whether the whole optimization game pays off on is chasing yield worth it, and read Bitcoin vs a savings account for where long-horizon savings might go instead.
- Bankrate. Best high-yield savings and CD rates · bankrate.com/banking/savings/rates.
- U.S. Department of the Treasury. Daily Treasury bill rates · home.treasury.gov.
- TreasuryDirect. I-bonds and T-bills · treasurydirect.gov. Purchase limits, lockups, and composite-rate mechanics.
- IRS Publication 550, Investment Income and Expenses · irs.gov. Treasury interest exemption from state tax (31 U.S.C. 3124).
- U.S. Bureau of Labor Statistics. Consumer Price Index · bls.gov/cpi. Headline CPI-U stamped at build (4.17% through May 2026).
- FDIC. Deposit insurance and national rate caps · fdic.gov.
Last updated 2026-07-12. Not financial advice. Do your own research.