A high-income W-2 employee lowers the tax bill mostly through forms the employer hands out: the W-4, the 401(k) election, benefits enrollment, the equity plan, and the deferred compensation election. Each one has a deadline set by payroll or HR, and most of those deadlines come before you know the year’s total pay.
A business owner or a landlord can deduct expenses against income. A salaried employee can’t deduct anything against wages. So your levers are elections, and each one has to be made on time with a good estimate of the year’s pay.
This guide covers only the levers that run through your employer. For strategies by income type (business, rental real estate, investments, and charitable giving), see tax strategies for high income earners.
| Lever | What it changes | When you decide |
|---|---|---|
| W-4 extra withholding | When tax is paid, and penalties | Any time |
| 401(k) pretax or Roth deferral | Taxable wages this year or later | Most plans: any pay period |
| After-tax 401(k) and in-plan Roth | Tax-free growth later | Plan rules |
| HSA through payroll | Income tax and payroll tax | Most plans: any month |
| Health FSA and Dependent Care FSA | Taxable wages | Open enrollment, then locked for the year |
| ESPP enrollment | Discount, and how the gain is taxed | Before each offering period |
| Stock option exercise, RSU sale | Bracket, AMT, concentration | Before each vest or exercise |
| Nonqualified deferred compensation | Which year salary or bonus is taxed | Generally by December 31 the year before |
Why does a high earner’s withholding come up short?
Bonuses and RSU vests are supplemental wages. Under IRS Publication 15, an employer can withhold federal tax on them at a flat 22%, and must use 37% on supplemental wages above $1 million in a year. Your bracket doesn’t enter into it.
If a $50,000 bonus lands entirely in the 35% bracket, it has $11,000 withheld against $17,500 of federal tax. The other $6,500 shows up as a balance due in April. The bonus tax calculator runs this on your own numbers, and RSU tax withholding covers the same gap for equity.
How do you close the gap through payroll?
Put an extra dollar amount per paycheck on line 4(c) of your W-4. Withholding has one advantage over estimated payments, and it’s in how the IRS dates it.
Under IRC 6654(g), wage withholding is treated as paid evenly across the year unless you choose otherwise. So $12,000 of extra withholding in December counts as $3,000 paid in each quarter. A $12,000 estimated payment sent in December counts only for the fourth quarter, and the first three quarters stay underpaid.
You avoid the underpayment penalty if total payments reach 90% of this year’s tax or 110% of last year’s tax when last year’s AGI topped $150,000. 2026 tax changes has the year-end checklist. If you changed jobs this year, each employer withheld as if it were your only job, and RSU vesting at a new job shows how to size the fix.
How should you set your 401(k) election?
For 2026 you can defer $24,500, plus $8,000 if you’re 50 or older, or $11,250 if you’re 60 to 63. Pretax deferrals lower this year’s taxable wages. Roth deferrals don’t, but the money comes out tax-free later. 401(k) contribution limits for 2026 has the full table.
Two employer rules matter more than the limit:
- The Roth catch-up rule. If your FICA wages from this employer topped $150,000 last year, any catch-up you make in 2026 must go to Roth. If the plan has no Roth option, you can’t make a catch-up at all.
- The match schedule. Many plans match each paycheck. Hit $24,500 by September and you may get no match on October through December pay. Check for an annual true-up before you raise your deferral rate.
Does your plan allow a mega backdoor Roth?
The 2026 cap on everything going into a 401(k), counting your deferral, the employer match, and after-tax money, is $72,000. If your plan accepts after-tax contributions and converts them to Roth inside the plan, the gap between your deferral plus match and $72,000 can go in as Roth money.
Only your plan document can answer whether this is open to you. Mega backdoor Roth 401(k) walks through how much to put in and when to convert.
Which benefits elections lower your taxable pay?
Three accounts come out of your paycheck before income tax:
- HSA: $4,400 for self-only coverage or $8,750 for family coverage in 2026, plus $1,000 at 55 or older, if you’re on an HSA-eligible health plan. Details in HSA contribution limits for 2026.
- Health FSA: up to $3,400 for 2026 plan years, under Rev. Proc. 2025-32. Plans may let $680 carry over.
- Dependent Care FSA: $7,500 per household in 2026, up from $5,000.
Run the HSA through payroll if your employer allows it. A payroll contribution skips Medicare tax, and Social Security tax on wages under the $184,500 wage base. Money you put into an HSA on your own gets the income tax deduction and nothing else. A 401(k) deferral is subject to both payroll taxes either way.
FSA elections lock at open enrollment. You can change them mid-year only after a qualifying event like a birth or marriage. Financial deadlines for 2026 lists the open enrollment and FSA dates.
How do equity elections change your tax?
RSUs vest on the company’s schedule. Everything after the vest is your call:
- RSUs: the vest is taxed as wages whether you sell or hold. Selling at vest adds little tax, because your basis is the value already taxed. Holding is an investment decision. RSU tax planning covers the full-year projection.
- ESPP: a qualified plan can sell you shares at up to a 15% discount, on up to $25,000 of stock a year valued at the offering date. How long you hold decides how much of the gain is wages. See how ESPP is taxed.
- Stock options: an NSO exercise adds wages and gets supplemental withholding. An ISO exercise adds no regular income but can trigger the alternative minimum tax. Model it before you exercise with how to avoid AMT on ISOs and ISO vs. NSO.
When does deferring salary or a bonus make sense?
A nonqualified deferred compensation plan lets you move salary or bonus into a later year. The election is generally due by December 31 of the year before you earn the pay, and it’s usually irrevocable once made.
It helps most if your income will drop later, at retirement or after a move to a state with lower tax. The cost is risk. Deferred amounts are usually an unsecured promise from your employer, so if the company fails, you’re a creditor. Pick the payout schedule when you elect. Changing it later generally means pushing each payment back at least 5 years.
You rarely control when a regular bonus is paid. If your employer lets you choose between December and January, that choice moves the income a full tax year.
What about strategies outside your paycheck?
They work for W-2 earners too, and each has its own guide:
- Backdoor Roth IRA when your income is above the Roth limit: backdoor Roth.
- Charitable giving, including appreciated stock and the 2026 0.5% of AGI floor: tax strategies for high income earners.
- Tax-loss harvesting in a taxable brokerage account: tax-loss harvesting.
How Nino handles the W-2 levers
Every lever above depends on one number nobody at your employer computes: your household’s total tax for the year. Payroll, HR, and the equity plan administrator each see one piece of it.
Nino puts a dedicated financial planner and a CPA on the same household numbers all year. They project every paycheck, bonus, and vest, then tell you what to put on the W-4, what deferral rate to set, which benefits to elect, and when to sell or exercise. The CPA then prepares and files your return from that same projection, so the plan and the return match. See how it works and plans and pricing.
Book a free consultation to walk through your pay stubs, vest schedule, and benefits elections before your next open enrollment.