Reading your pay stub after an RSU vest: wages, withholding, and net pay

Payroll treats RSU delivery as taxable wages in the pay period when the vest processes. Regular salary lines and vest wage lines often share one stub, so gross jumps by roughly FMV times shares even when your biweekly salary did not change. If gross did not move, the vest may post on a later paycheck or a separate off-cycle run — compare the equity portal confirmation date to the stub pay date before calling HR.

Federal income tax on supplemental wages often uses a flat rate under IRS Publication 15 unless your employer aggregates vest and salary into one withholding calculation. Social Security and Medicare apply to vest wages like salary, so FICA lines can spike on the vest stub; Social Security stops after the annual wage base while Medicare generally continues. State withholding follows your employer’s payroll setup and W-4 state elections, not the federal flat rate.

Sell-to-cover does not shrink gross wages on the stub. Full vest FMV is still wages; shares sold for tax are a separate brokerage event that may appear later on Form 1099-B. Net direct deposit is cash only — it never includes the value of net shares deposited to your brokerage account, which is why a “tiny paycheck” can coexist with a large equity deposit.

401(k) and HSA deferrals usually apply to salary, not RSU vest gross, so do not expect the vest line to be shielded by pre-tax retirement contributions. YTD boxes help you track cumulative wages and withholding after major vests; December’s last stub should reconcile toward W-2 Box 1, including every vest FMV that posted during the year.

Stub abbreviations vary — SUPP, BONUS, STOCK, RSU, or NQ may label supplemental withholding — but the math still needs to match confirmation FMV. A normal-looking net paycheck is not proof of full-year tax coverage when supplemental rates under-withhold relative to your stacked salary and remaining vests.

• ✓Gross wages increased by about vest FMV on the confirmation.
• ✓Federal withholding line vs supplemental rate on the confirmation.
• ✓FICA lines: Social Security and Medicare on vest wages.
• ✓State withholding if applicable.
• ✓YTD federal and state withheld after the vest vs an annual estimate.
• ✓Net shares in brokerage vs sell-to-cover on the confirmation.
• ✓Whether the vest posted on the expected pay date or one period late.

• ✓Vest pay stub PDF from the HR portal.
• ✓Prior pay stub for baseline salary withholding.
• ✓Vest confirmation with FMV and withholding rate.
• ✓Brokerage deposit notification.
• ✓December YTD pay stub before filing season.

• ✓Pay stub gross still excludes vest FMV after two pay cycles.
• ✓Payroll withheld zero federal tax on a large vest.
• ✓Multi-state payroll on the vest stub after a move.
• ✓Negative net pay with unclear recovery from later checks.