Where your cash keeps the most after tax
The highest yield isn't always the most money. Treasury interest is free of state tax, municipal funds skip federal tax, and high earners pay a 3.8% surtax on the rest. Set your taxes and see what each option actually leaves you.
| Option | Pays | You keep | Per year | vs the best |
|---|
Your fund's share of income from U.S. government obligations is in the tax notice its company publishes each January. The 9% default state rate is Massachusetts' 5% plus its 4% surtax on income over about $1 million; change it to yours. Yields move daily; each links to its source and date. Not tax advice; your tax preparer has the final word.
How the math works
You keep the yield times one minus your tax rates. Treasury bills skip state tax entirely. A money fund passes through the state exemption only on the share of its income that came from U.S. government obligations, and California, Connecticut and New York allow even that only if the fund kept at least half its assets in them. Municipal funds skip federal tax and the 3.8% surtax but are usually taxed by your state unless they hold only its bonds. We ignore the state-tax deduction, since most high earners are already at the SALT cap.
How we check every number
A rate goes on this site only if we can point to where it came from. If we can't, the row stays hidden.
Official data first
Treasury yields come straight from the U.S. Treasury's daily yield curve, pulled automatically every weekday evening. A rate that jumps more than a full point overnight is held back until it's confirmed.
The broker's own page
Sweep rates are read from each broker's published rate sheet or disclosure. News articles and forums tell us something changed; they are never the source of the number.
No paid placement
No broker or bank on this page pays us today. If one ever does, it will say so next to the row, and the order won't change.