For U.S. taxable accounts · Yields as of Oct 2, 2026
Where does your cash earn the most after tax?
Highest estimated after-tax yield
+$942Muni money fund
More over 1 year than in high-yield savings. On $100,000, estimated.
Where it is now
High-yield savings
Keeps the most
Muni money fund
- Access
- Next business day
- Kept
- $2,809 a year
- Before
- $3,097 before tax
- Price
- Aims for a stable $1 a share
High-yield savings pays more before tax. It would come out ahead only while the tax on it is under 17.4%. Yours is 45.1%.
Your tax on interest
54.9¢
kept from each $1 of fully taxable interest
Kept after tax, on $100,000 over 1 year
The line is what you keep.
01 Muni money fund National municipal money market fund, 7-day yield
How it’s taxed
y × (1 − s − l)
3.10% × (1 − 9.30%) = 2.81%
- Federal
- –
- NIIT
- –
- State
- −0.29%
- Local
- –
- Kept
- 2.81%
- Taxable equiv.
- 5.12%
3.05% 7-day yield = 3.10% a year, compounded
$2,809 kept over 1 year on $100,000, vs. $3,097 before tax.
Estimate 7-day yield as of Oct 5, 2026. Our estimate: about 77% of the taxable money fund estimate, a typical ratio for weekly-reset munis. Not a quote from any fund. Source ↗
- Treated as fully taxable by California. The share from your own state’s bonds may be exempt; California requires the fund to hold at least 50% California bonds first.
Interest income only, not price changes. Rates marked “estimate” are ours, not quotes. Check any rate with the provider before you act.
Same 6 options, two orders
Before and after tax
On the left, the options in order of their advertised rate. On the right, the same options in order of what you keep after federal, state and local tax.
Savings, CDs and brokerage cash are taxed at every level, so they tend to fall. T-bills skip state tax and muni money funds skip federal tax, so they tend to rise. Change your state or income above and the lines move with it.
Assumptions Your own tax rates, state tax deduction, AMT, Social Security, money fund tax facts, inflation
You haven't changed any rates. To change one, open its row in the ranking.
Show the math Every rate applied, and where it came from
Federal marginal rate
Taxable income $203,900 falls in the $201,775–$256,225 bracket.
IRS Rev. Proc. 2025-32 (tax year 2026)
Net investment income tax
Modified AGI of about $220,000 is above the $200,000 threshold, so all new taxable interest pays it.
IRC §1411; IRS Topic 559 (thresholds are not indexed)
California marginal rate
9.30% at your taxable income.
California revenue department, tax year 2025
Local rate
No local income tax selected.
—
Taxable income = $220,000 gross − $16,100 standard deduction. Rates are marginal: they apply to the next dollar of interest you earn.
Formulas, with your numbers
Fully taxable savings, CDs, brokerage cash, corporate bonds
y × (1 − f − n − s − l) = y × 0.5490
Treasuries, TIPS, I bonds, most agencies no state or local tax
y × (1 − f − n) = y × 0.6420
Out-of-state munis no federal tax
y × (1 − s − l) = y × 0.9070
In-state munis
y
Government money market t = income share from US obligations, 40%; CA sets t = 0 unless the fund met its 50% asset test (you said it didn’t)
y × (1 − f − n − (s + l) × (1 − t))
Taxable-equivalent yield
after-tax ÷ (1 − f − n − s − l) = after-tax ÷ 0.5490
Each quoted yield is first converted to an effective annual rate: APYs as is, 7-day money fund yields compounded daily, bond-equivalent and SEC yields compounded twice a year. Dollars assume interest is reinvested at the same after-tax rate over your timeline. Bond yields are income, not total return: prices can move. State tax deductibility, AMT and Social Security effects are toggles under "Assumptions", and the full list of simplifications is on the methodology page.
Side by side, with your numbers
Common comparisons
- Muni vs Treasury Munis or Treasuries? A lower muni yield can leave you with more. Find your break-even tax rate, for cash or for money you can invest for years.
- Fund vs fund VMSXX or VUSXX? Vanguard’s municipal and Treasury money funds, compared on what you keep in your state.
- Bill vs bank T-bills or savings? A bill against your own savings rate at your state’s tax rate: the difference in dollars, and what you give up in access.
- Break-even What tax rate makes a muni worth it? The taxable yield a muni matches for you, and the tax rate at which the two tie.
How each option is taxed
For cash you may need soon
- Brokerage cash programs Your broker sweeps idle cash into partner banks and pays you a share of the interest.
- High-yield savings An FDIC-insured bank savings account, usually online, paying several times the national average.
- Government money market funds A mutual fund holding short-term government debt and repo, priced at a stable $1 a share.
- Municipal money market funds A money market fund that holds short-term municipal debt, so its dividends are free of federal tax.
- Treasury bills Short-term US government debt, from 4 weeks to 52 weeks, sold at a discount and repaid at face value.
- Certificates of deposit A bank deposit with a fixed rate for a fixed term, bought from a bank or through a brokerage.
For income over several years
- Treasury notes and bonds US government debt from 2 to 30 years that pays interest every six months.
- TIPS Treasury Inflation-Protected Securities: principal rises with CPI, so you earn a fixed real yield.
- I bonds Inflation-linked US savings bonds sold only through TreasuryDirect, with a yearly purchase cap.
- Municipal bonds, in-state Bonds issued by your own state, its cities and agencies, with interest usually free of federal and state tax.
- Municipal bonds, national Munis from many states, usually through a fund. Federally exempt, but your state usually taxes them.
- Agency bonds Bonds from government-sponsored lenders like the Federal Home Loan Banks and Farm Credit System.
- Investment-grade corporate bonds Bonds from companies rated BBB or better, paying a spread over Treasuries for credit risk.