IRS Publication 525 restricted stock units vesting events map to Form W-2 as ordinary wages: settlement-date fair market value × shares lands in Box 1, FICA wages in Boxes 3 and 5, and federal withholding in Box 2—often at the 22% supplemental rate under Publication 15-T. Publication 525 (Taxable and Nontaxable Income) classifies RSU settlement under its wages and compensation chapter via IRC Section 83, not as investment income. When your employer uses sell-to-cover, shares sold at vest fund withholding, but Box 1 still reflects gross vest FMV—not net shares delivered.
Verified against IRS Publication 525 (2025) and Instructions for Forms W-2 and W-3, accessed 28 August 2026. As of the 2026 filing season, major equity administrators (Fidelity Stock Plan Services, Schwab Equity Awards, Morgan Stanley Shareworks, E*TRADE Corporate Services) still report RSU vest FMV in Box 1 with supplemental withholding in Box 2—this guide maps each W-2 box to the Publication 525 wage rule employees reconcile every January.
Box 1
the W-2 spine where RSU vest FMV must appear under Publication 525 wage classification
Box 14 labels and sell-to-cover net deposits are explanatory—Box 1 is what flows to Form 1040 Line 1a
Publication 525 framework: why RSU vesting is W-2 wages
IRS Publication 525 operates on a simple rule: all income is taxable unless the law specifically excludes it. RSU settlement at vest falls in the employee wages bucket governed by IRC Section 83—not beside dividends, interest, or capital gains.
Under Section 83(a), you recognize income when property transferred for services is no longer subject to a substantial risk of forfeiture. For typical RSUs, that moment is the settlement date when shares deliver and your right becomes unconditional:
W-2 wage inclusion at vest = FMV per share on settlement date × number of shares vesting
This is ordinary compensation, reported on Form W-2—not a separate "RSU income" category. Publication 525 groups RSU vesting with salary, bonuses, and other taxable wages. Your employer's payroll system translates that wage classification into specific W-2 boxes.
| Publication 525 classification | RSU tax event | Primary W-2 destination |
|---|---|---|
| No income (pre-vest) | Grant to forfeiture | No W-2 entry |
| Ordinary wages | Vest / settlement | Box 1 (+ Boxes 3, 5 for FICA) |
| Withholding prepayment | Same vest event | Box 2 (federal), Boxes 4, 6 (FICA) |
| Optional memo | Same vest event | Box 14 (employer label) |
For the broader Pub. 525 lifecycle (constructive receipt, double-trigger, cost basis at sale), see IRS Publication 525 RSU Tax Guide: Taxed When Vested. For Form 1040 line mapping, see IRS Pub 525 RSU Tax Rules & Reporting Guide.
W-2 box-by-box map for RSU vesting events
Methodology (28 August 2026): We compared RSU vest W-2 reporting instructions from six public equity administrators—Fidelity Stock Plan Services, Charles Schwab Equity Awards, Morgan Stanley Shareworks, E*TRADE Corporate Services, Computershare, and Carta (private-company plans)—against IRS Instructions for Forms W-2 and W-3 and Publication 525 wage-framing language. The matrix below reflects how each box typically behaves for a standard same-day RSU settlement with sell-to-cover.
| W-2 box | RSU vest content (typical) | Publication 525 tie-in | Common employee mistake |
|---|---|---|---|
| Box 1 | Gross vest FMV × shares | Ordinary wages per Section 83 | Thinking net shares × FMV is the wage amount |
| Box 2 | Federal income tax withheld | Prepayment—not final tax liability | Assuming 22% withholding = taxes paid in full |
| Box 3 | Social Security wages (includes RSU FMV) | FICA wage base; may cap mid-year | Expecting Box 3 to equal Box 1 all year |
| Box 4 | Social Security tax withheld | 6.2% on Box 3 (up to wage base) | Ignoring when SS wages stop increasing |
| Box 5 | Medicare wages (includes RSU FMV) | No annual cap on Medicare wages | Skipping Additional Medicare Tax check |
| Box 6 | Medicare tax withheld | 1.45% + 0.9% Additional Medicare above threshold | Missing 0.9% on high earners |
| Box 12 | Usually no RSU code (Code V = options/ESPP) | Different equity events | Searching for Code V on pure RSU vests |
| Box 14 | Optional "RSU" memo label | Informational—not additive | Adding Box 14 to Box 1 (double-count) |
| Boxes 15–20 | State wages and withholding | State conforms on wage character | Ignoring state gaps when relocating mid-year |
Where I'm less sure—employers that settle RSUs through a non-US payroll entity while you work in the US may issue different forms (or split W-2 reporting across entities after M&A). The Publication 525 wage rule still applies to US-source compensation, but the box layout may require two W-2s. Cross-border cases need a CPA, not a box-guessing exercise.
Box 1: the wage spine every RSU holder must reconcile
Box 1 (Wages, tips, other compensation) is where Publication 525's wage classification becomes a number you can verify. Your employer includes gross vest FMV—the full economic value of shares settling—not the net shares deposited after sell-to-cover.
Take Priya, a staff engineer at Intuit (illustrative). On 15 February 2026, 300 RSUs vest when INTU closes at $612.00:
| Line item | Amount |
|---|---|
| Gross vest FMV (300 × $612) | $183,600 |
| Federal withholding (22% supplemental) | $40,392 |
| Social Security (6.2%, illustrative) | $11,383 |
| Medicare (1.45% + 0.9% Additional) | $4,262 |
| Shares sold (sell-to-cover, illustrative) | ~95 shares |
| Net shares delivered | ~205 shares |
| Box 1 wage inclusion | $183,600 |
Priya's brokerage shows ~205 shares—not 300—because sell-to-cover funded taxes. But her Box 1 includes the full $183,600. That same per-share FMV ($612) becomes her cost basis when she later sells. Anecdotally, this gross-vs-net confusion is the #1 W-2 support ticket equity admins field in Q1—your mileage will vary by employer portal design, but the IRS wage rule does not.
Steel-man: "If my employer sold shares to pay taxes, shouldn't Box 1 only show the net value I actually received?"
Best case for net reporting: Sell-to-cover feels like you only "got" net shares, so wages should match net economics.
Rebuttal: Section 83 taxes the full FMV at settlement. The withholding sale is a separate disposition—you received gross wages and simultaneously sold shares to fund withholding. Box 1 reflects gross compensation; the broker confirmation shows shares sold.
Box 2 and supplemental withholding: sell-to-cover funding
Federal income tax withholding on RSU vests typically follows supplemental wage rules in IRS Publication 15-T:
| Cumulative supplemental wages (per employer, per year) | Federal flat withholding rate |
|---|---|
| Up to $1,000,000 | 22% |
| Above $1,000,000 | 37% on the excess |
Box 2 shows what was actually withheld—not your final tax liability. If Priya's marginal federal rate is 35%, the 22% supplemental rate leaves a 13-point gap on $183,600 of vest income—potentially $23,868 before state taxes and FICA stacking.
Sell-to-cover mechanics tie directly to Box 2:
- Employer calculates estimated taxes on gross vest FMV.
- Plan sells whole shares at vest FMV until proceeds cover withholding.
- Box 2 reflects federal withholding remitted; Box 1 stays at gross FMV.
- Net shares land in your brokerage account.
For deeper sell-to-cover math, see RSU sell-to-cover withholding explained. For why 22% often falls short, see RSU and option withholding: why 22% may not be enough.
Critical warning: Supplemental withholding is a prepayment. A large Box 2 number does not mean you are done—compare withholding to your marginal bracket and state obligations.
FICA boxes (3–6): Medicare keeps climbing after Social Security caps
RSU vest FMV flows into Social Security wages (Box 3) and Medicare wages (Box 5) alongside regular salary. Key differences:
| Box | 2026 behavior for high earners | RSU impact |
|---|---|---|
| Box 3 | Caps at Social Security wage base ($176,100 for 2026) | Large Q1 RSU vest may max out SS wages early |
| Box 5 | No cap | RSU FMV keeps increasing Medicare wages all year |
| Box 6 | 1.45% + 0.9% Additional Medicare above $200,000 | Big vest can trigger Additional Medicare in one paycheck |
Take Marcus, a director at Palo Alto Networks (illustrative). His YTD wages before a March RSU vest are $170,000. A $90,000 RSU vest pushes Box 3 to the $176,100 cap—only $6,100 of the RSU FMV attracts Social Security tax. But all $90,000 still increases Box 5 Medicare wages.
I haven't tested every payroll engine's rounding on partial-SS scenarios—some systems split FICA across regular and supplemental paychecks differently. Match your December pay stub detail to Boxes 3–6 rather than assuming proportional allocation.
Box 12 and Box 14: what RSU vesting does not use
Box 12 — Code V is for options and ESPP, not standard RSU vests
Box 12 Code V reports income from the exercise of nonstatutory stock options and certain ESPP disqualifying dispositions. Standard RSU vesting—where you never exercise an option—typically generates no Code V entry. The wage amount is already embedded in Box 1.
| Equity event | Typical Box 12 code | Box 1 impact |
|---|---|---|
| RSU vest (standard) | None (wages in Box 1 only) | FMV × shares |
| NSO exercise | Code V | Spread in Box 1 + Code V |
| ESPP disqualifying sale | Code V (often) | Discount/spread in Box 1 |
Box 14 — employer memo, not a second wage total
Box 14 is optional space for employer-defined labels—"RSU," "STOCK," state disability programs, or internal GL codes. Amounts labeled in Box 14 are almost always already included in Box 1.
Wrong: Box 1 = $400,000 + Box 14 RSU = $120,000 → report $520,000 wages.
Right: Confirm the $120,000 is inside the $400,000 Box 1 total; Box 14 is a memo.
See W-2 Box 14 codes for equity compensation explained for label-by-label decoding.
Sell-to-cover: how withholding sales interact with W-2 boxes
Sell-to-cover creates two economic events on vest day that map to different forms:
| Event | W-2 impact | Other forms |
|---|---|---|
| RSU settlement (wages) | Box 1 += gross FMV; Boxes 2–6 += withholding | None at vest |
| Share sale for withholding | No change to Box 1 | Broker may issue 1099-B for shares sold |
The withholding sale is not a reduction of Box 1 wages. Publication 525's wage rule taxes gross settlement FMV. When you later sell held shares, your basis equals the vest FMV already in Box 1—reconciled on Form 8949, not the W-2.
Verdict: For a typical tech employee with sell-to-cover, trust Box 1 as gross vest wages, use equity supplements for per-vest FMV detail, and treat Box 14 as optional commentary. If your marginal rate exceeds 24%, plan for a withholding gap before year-end—adjust Form W-4 or make estimated tax payments rather than hoping Box 2 tells the whole story.
Working checklist: January W-2 tie-out for RSU holders
| Step | Action | Box to verify |
|---|---|---|
| 1 | Download annual equity supplement (all vest events) | Per-vest FMV detail |
| 2 | Sum vest FMV × shares across all tranches | Should reconcile to Box 1 delta vs salary-only |
| 3 | Compare Box 2 withholding to marginal bracket | Gap planning |
| 4 | Check Boxes 3/5 for SS cap and Medicare continuity | FICA surprises |
| 5 | Read Box 14 as memo—do not add to Box 1 | Avoid double-count |
| 6 | Save vest confirmations for Form 8949 basis at sale | Future Schedule D |
Pair this with how to report RSU income on your tax return when sale season arrives.
Frequently Asked Questions
Does IRS Publication 525 require a separate RSU line on Form W-2?
Answer: No. Publication 525 classifies RSU settlement as ordinary wages that belong in Box 1 alongside salary and bonus. There is no dedicated "RSU box"—the wage classification drives Box 1 inclusion under IRC Section 83.
Source: IRS Publication 525; IRC Section 83
Why is my Box 1 so high after RSU vesting if I only received net shares?
Answer: Box 1 reflects gross vest FMV (all shares × settlement price), not net shares after sell-to-cover. The shares sold for withholding are a separate transaction; wages are still computed on the full settlement value.
Source: IRS Instructions for Forms W-2 and W-3
Does sell-to-cover reduce the amount in Box 1?
Answer: No. Sell-to-cover funds withholding (Box 2 and FICA boxes) by selling shares. Box 1 still includes the full vest FMV as wages under Publication 525's compensation classification.
Source: IRS Publication 525; IRS Publication 15-T
What W-2 box shows RSU ordinary income specifically?
Answer: Box 1 is the authoritative wage total. Box 14 may label a portion as "RSU" for employer communication, but that amount is typically already inside Box 1—not an additional wage line.
Source: IRS Instructions for Forms W-2 and W-3
Is Box 12 Code V used for RSU vesting?
Answer: Generally no. Code V reports spreads from nonstatutory stock option exercises and certain ESPP events. Standard RSU vesting is wage income in Box 1 without a Code V entry.
Source: IRS Instructions for Forms W-2 and W-3
Why was only 22% withheld on my RSU vest when my tax bracket is higher?
Answer: Employers often use the 22% supplemental wage flat rate (Publication 15-T) for federal withholding on RSU vests below $1 million cumulative supplemental wages. That is a prepayment, not your final tax rate. Plan for additional tax via W-4 adjustments or estimated payments.
Source: IRS Publication 15-T
Do RSU wages in Box 1 affect Social Security and Medicare boxes?
Answer: Yes. Vest FMV is included in Box 3 (Social Security wages, subject to the annual wage base) and Box 5 (Medicare wages, no cap). Boxes 4 and 6 show the corresponding taxes withheld.
Source: IRS Instructions for Forms W-2 and W-3
Where does RSU vest FMV go when I file Form 1040?
Answer: Box 1 wages import to Form 1040, Line 1a. You do not enter RSU income separately. When you sell shares, report gain/loss on Form 8949 using vest FMV as basis.
Source: IRS Publication 525; Instructions for Form 8949
Footnotes
Primary Sources
| Source | Type | URL |
|---|---|---|
| IRS — Publication 525 (2025) | Federal | irs.gov/publications/p525 |
| IRS — Instructions for Forms W-2 and W-3 | Federal | irs.gov/instructions/iw2w3 |
| IRS — Publication 15-T (2025) | Federal | irs.gov/publications/p15t |
| IRC — Section 83 | Statute | law.cornell.edu/uscode/text/26/83 |
| IRS — Topic 427, Stock options | Federal | irs.gov/taxtopics/tc427 |
Disclaimer: This guide discusses legal tax compliance and literacy only. Tax evasion is illegal. This is not individualized tax advice. Consult a qualified professional for your facts.