Withheld at 22%, Taxed at 32%: The Severance Reconciliation Gap in 2026

How Large Is the Gap Between 22% Withholding and the Real Tax Bill?

$44,000 withheld; roughly $64,000 owed. That is the arithmetic on a $200,000 severance package paid to a recipient whose marginal federal rate is 32%. Payroll applies the flat 22% supplemental withholding rate, the actual liability on those dollars accrues at the recipient’s bracket, and the difference — about $20,000 — surfaces as a balance due the following April. Without an estimated payment by January 15, an underpayment penalty rides along with it.

The mechanism behind the 22% is settled and heavily explained elsewhere. IRS Publication 15-A classifies severance as supplemental wages — the same bucket as bonuses, commissions, back pay, awards, accumulated sick and vacation payouts, certain overtime calculations, and taxable fringe benefits. The label tracks the payment’s character, not its size: a $5,000 bonus and a $500,000 package sit in the same category. Employers may withhold on these payments at a flat 22% up to $1 million per employee per calendar year, with a mandatory 37% on any excess, or may use the aggregate method, which folds the payment into the regular withholding tables against the most recent regular paycheck. Large payroll systems default to the flat rate for administrative reasons.

That much is the standard explainer, and it is not the subject here. The subject is what the flat rate does at filing time to everyone whose marginal bracket sits above 22% — which describes most white-collar severance recipients — and the two mechanical fixes, safe-harbor estimated payments and payment-timing structure, that decide whether the gap arrives with a penalty attached.

Who Under-Withholds at 22%, and by Roughly How Much?

Actual federal tax reconciles on Form 1040 against total annual income and the progressive brackets, with severance counted as ordinary taxable income per IRS Publication 525. The 2025 single-filer brackets per IRS Publication 17 (2026 brackets adjust upward roughly 2–3% for inflation):

Bracket	Income range (single filer)
10%	$0 to $11,925
12%	$11,925 to $48,475
22%	$48,475 to $103,350
24%	$103,350 to $197,300
32%	$197,300 to $250,525
35%	$250,525 to $626,350
37%	above $626,350

Married-filing-jointly thresholds run approximately double, except the top 37% bracket, which begins at $751,600.

Four reconciliations show the pattern:

• $35,000 wages + $20,000 severance, single. Total $55,000; marginal rate 22%. Withholding matches liability on the severance almost exactly. Adjustment at filing: near zero.
• $80,000 wages + $40,000 severance, single. Total $120,000; the severance dollars land in the 24% bracket. The 2-point gap produces roughly $800 of additional federal tax due.
• $300,000 joint wages + $150,000 severance, married filing jointly. Total $450,000; the top dollars sit in the 32% bracket. The roughly 10-point gap on the severance produces on the order of $15,000 due at filing.
• $400,000 wages + $200,000 severance, single. Total $600,000; marginal rate 35%. The 13-point gap produces roughly $26,000 of additional federal tax — enough to trigger an underpayment penalty if nothing is prepaid during the year.

Below the 22% bracket the arithmetic flips: a 12%-bracket recipient is over-withheld and collects the difference as a refund. For the under-withheld majority, the typical filing-time balance on white-collar packages runs $5,000 to $30,000, scaling with the severance amount and the bracket.

What Does the 90%/100%/110% Safe Harbor on Form 1040-ES Require?

The federal system requires tax to be paid as income arrives, not settled in April. A balance due is legal; an under-prepaid balance accrues a penalty computed like interest — the federal short-term rate plus three percentage points, measured quarter by quarter on Form 2210. Form 1040-ES defines the safe harbors that switch the penalty off. Total withholding plus estimated payments must reach either:

1. 90% of the current year’s actual tax, or
2. 100% of the prior year’s total tax — 110% if prior-year AGI exceeded $150,000.

The prior-year prong is the useful one in a severance year, because it is a known number in January while the current-year figure is still a forecast. An executive whose prior-year total tax was $90,000, with AGI above $150,000, needs $99,000 of total payments. If year-to-date withholding — regular paychecks plus the 22% taken from the severance — comes to $80,000, a single $19,000 estimated payment by January 15 satisfies the safe harbor, even if the final April balance is several times larger. A $400,000-per-year executive separated in August with $200,000 of severance withheld at 22% almost always needs exactly this move.

Withholding has one property estimated payments lack: the IRS treats it as paid evenly across the year regardless of when it actually came out. A recipient who discovers the gap in October can ask payroll to over-withhold on remaining paychecks — or on a final severance installment — and the extra amounts retroactively cover the early quarters. Estimated payments count only from the date paid. For late-year discoveries, the withholding route can erase penalty exposure that a January estimated payment merely stops from growing.

There is a fallback for those who miss every safe harbor. Form 2210’s annualized income installment method recomputes the penalty quarter by quarter based on when income actually arrived. A severance check received in November generated no payment obligation in April or June of that year, and annualizing documents that. The method takes a schedule’s worth of arithmetic, but for a package concentrated in Q4 it routinely shrinks the penalty to a fraction of the default calculation.

How Do Installments and the $1 Million Threshold Change the Timing?

Each severance installment is supplemental wages when paid, withheld at 22% — or at the mandatory 37% once a single employer’s supplemental payments to one employee pass $1 million in a calendar year. The threshold counts per employee, per employer, per year, which makes payment structure a live variable in three situations: partner-level separations at law and consulting firms, senior-executive packages at public companies, and any year where annual bonus, separation pay, and accelerated deferred compensation land together. A package combining $750,000 severance, $400,000 accelerated bonus, and $200,000 of deferred-comp payout crosses mid-stream; the final $350,000 is withheld at 37%. That rate is also the top marginal bracket — the rule is built to approximate the true tax for earners at that altitude.

Timing moves both the withholding and the substance:

• Lump sum in December versus split across January 1. A $1.4 million package paid at once has $400,000 withheld at 37%. The same package paid $700,000 in December and $700,000 in January stays under the threshold in both calendar years and is withheld entirely at 22%. The withholding difference is cash flow, not final tax — but the split also divides the income across two tax years, which is substance.
• Income-shifting for ordinary packages. A late-year separation that pushes payment into January moves the income into a year that may contain no salary at all. On $100,000 of severance, landing it in a low-income year instead of stacking it on a full year of wages is frequently worth $10,000 or more in federal tax.
• Salary continuation. Six months of continuation pay withholds 22% per pay period and can straddle the calendar boundary on its own, crossing the $1 million threshold at a different point than a lump sum would have — or never crossing at all.

Do State Supplemental Rates Follow the Same Pattern?

They do, and the essentials compress to a paragraph. States with income taxes run their own supplemental withholding on top of the federal 22%: California at 6.6% (10.23% for stock options and large bonuses), New York at 11.7% for high earners plus 4.25% for New York City residents, New Jersey graduated to 11.8%, Massachusetts at 5%, Illinois at 4.95%. Texas, Florida, Washington, Nevada, South Dakota, Tennessee, Wyoming, and Alaska withhold nothing. A New York City recipient of $100,000 sees 37.95% combined withholding before FICA; a Texan sees 22% plus FICA. Every state layer reconciles on the state return exactly the way the federal layer does on the 1040 — withholding first, true bracket math later. The per-state arithmetic lives in the Texas breakdown and the New York breakdown.

What Belongs on the Calendar Between Separation and April 15?

The reconciliation gap rewards a short sequence, not sophistication:

1. At signing: estimate the marginal bracket on total expected annual income, severance included. Anything above 22% means a federal balance is quietly accruing from the day the check clears.
2. Before the final installment or paycheck: choose between extra payroll withholding (retroactive even-spread treatment) and a Q4 estimated payment (counts from the date paid). Size either to the 100%/110% prior-year safe harbor.
3. January 15: last day for the Q4 estimated payment covering the separation year.
4. For packages near $1 million, or where next year’s income will be materially lower: raise payment timing with the employer before signing. Splitting across calendar years is a negotiation item, not a payroll favor.

Tax law changes annually; this article reflects 2026 rates and is refreshed each January. Consider consulting a CPA or tax attorney for advice specific to your situation, particularly for high-dollar severance, multi-state allocations, or separations involving deferred compensation.