Tennessee RSU Tax Calculator 2026
Tennessee employees: no state income tax — but your federal withholding gap is real. See the exact amount your employer under-withholds and what to pay quarterly.
After your company withholds 22%, you'll owe
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Set aside now
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✅ Pay this now to avoid an IRS penalty
Sell-to-cover ≠ paid in full
⚠ Don't get taxed twice when you sell
Owe a surprise bill?
RSU Taxes in Tennessee: What the Flat Rate Misses
Tennessee levies no state income tax on wages — which sounds like a win, and it is. But it does not eliminate your federal withholding gap. When your employer withholds RSU shares at the flat federal supplemental rate of 22% (or 37% for vest income over $1 million in a single year), that withholding almost always falls short of what you actually owe at the federal level once your total income is counted. For a high-earning Tennessee tech employee in the 32% or 35% federal bracket, the gap can run $15,000–$60,000 or more per vest event — and the IRS assesses an underpayment penalty if you don't address it quarterly.
The Federal Withholding Gap: 22% vs. Your Actual Bracket
Regardless of Tennessee's state tax rules, every RSU vest triggers a federal supplemental withholding event. The IRS mandates a flat 22% for supplemental wages up to $1 million (per employer, per year). Once cumulative supplemental wages from a single employer cross $1 million in a calendar year, the rate jumps to 37% on the excess. Most tech employees vesting $100k–$500k per year are in the 32% or 35% federal bracket by the time RSU income is counted — creating a gap of 10–15 percentage points that the flat 22% withholding misses entirely. On a $300,000 vest, that federal gap alone can exceed $39,000.
What to Do After Every Vest
The fix is straightforward but requires action before the next estimated tax deadline (typically April 15, June 15, September 15, or January 15). After every vest, run this calculator to compute your precise underpayment. Then make a direct payment to the IRS via IRS Direct Pay and to the Tennessee tax authority to cover the gap. Timing matters: the IRS safe-harbor rules generally require you to have paid 90% of the current year's liability, or 100% (or 110% for AGI over $150k) of last year's liability — whichever is smaller — through withholding or estimated payments.
For a deeper explanation of how the withholding gap works and a step-by-step guide to quarterly payments, see our RSU Withholding Gap guide. If you've already sold your RSU shares and your brokerage's 1099-B shows $0 cost basis, read our RSU Cost Basis Double-Tax guide before filing — it explains how to correct Form 8949 to avoid paying tax twice.
Sell-to-Cover: You Still Owe More
Most employers automatically sell a portion of your vesting shares to cover the mandatory withholding — a mechanism called "sell-to-cover" or "net settlement." This feels like the tax is handled, but it only satisfies the withheld amount (22% federal + 0% state). The remaining gap between what was withheld and what you truly owe at your marginal rate is still your responsibility. This calculator shows your sell-to-cover proceeds separately from the gap that remains after the sell, so you know exactly what you still need to pay.
Back to the RSU Tax Calculator home to compare other scenarios or try a different vest date or share price.
Frequently Asked Questions — Tennessee RSU Taxes
Why does my Tennessee employer withhold RSU taxes at a flat rate instead of my actual bracket?
For federal tax, the IRS requires employers to use a flat 22% supplemental rate (37% above $1 million) rather than calculating your individual bracket. Since Tennessee has no state income tax on wages, there is no state withholding component — but the federal flat-rate withholding still applies and is almost always lower than your true marginal federal rate if you're earning over $89,075 as a single filer.
Do I owe Tennessee taxes on RSUs if I no longer live there when I sell the shares?
Since Tennessee has no income tax on wages, there's nothing to worry about at the state level for the vest event itself. However, if you later sell the shares at a gain, the capital gains tax in your state of residence at the time of sale would apply.
What is the cost basis for my RSU shares, and why does my 1099-B show $0?
Your cost basis for RSU shares is the fair market value (FMV) at vest — the same amount your employer already reported as ordinary income on your W-2. Brokerages are only required to report the adjusted basis to the IRS for shares acquired after 2011, and many report $0 or only the amount you paid (nothing, for RSUs). If you sell the shares and report the 1099-B proceeds against a $0 basis, you'll be taxed twice on the same income. On Form 8949, use Code B (basis not reported to IRS) and manually enter the FMV at vest as your cost basis. See our RSU Cost Basis Double-Tax guide for a step-by-step walkthrough.
How much should I set aside after each vest to cover my gap?
Run every vest through this calculator. The "Set Aside Now" number is the hero figure — it's the after-withholding gap you need to hold in cash or a money-market account until you pay your next quarterly estimated tax. A common rule of thumb: set aside an additional 10%–18% of vest FMV above what was withheld, depending on your federal marginal rate. The calculator shows you the exact number based on your actual income and filing status.
RSU Tax Calculators for Other States
Compare your Tennessee results with other states — especially if you're considering relocating before a large vest.