Life event · W-2 · Multi-employer
Job-Change Taxes: The Refund Most Switchers Miss
Two W-2s in one year triggers a small pile of tax mechanics — one of which is free money.
The Excess Social Security Credit
Each employer withholds 6.2% Social Security up to the annual wage base — $184,500 in 2026 — with no knowledge of your other jobs. Two employers in one year can push your combined withholding well past the per-person maximum.
Per-person max (2026): $11,439
Per-person max (2025): $10,918.2
Worked example — 2026, two jobs
Employer A wages: $120,000 → SS withheld $7,440.00
Employer B wages: $100,000 → SS withheld $6,200.00
Combined withheld: $13,640.00
Per-person max (2026): −$11,439.00
Schedule 3 credit: $2,201.00
Your tax software claims this automatically when you enter both W-2s. Run your own numbers in the Excess SS Calculator.
Exception: the one-employer trap
If a SINGLE employer over-withheld past the maximum (payroll error, duplicate wage lines after an acquisition), Schedule 3 does NOT apply. You must ask that employer for a corrected W-2 (Form W-2c) and a refund. If they refuse, file Form 843 with a written statement from the employer.
The 401(k) Shared-Limit Trap
The elective deferral limit follows the PERSON, not the employer — $23,500 in 2025, $24,500 in 2026 across every 401(k) you contribute to (plus catch-ups if age 50+). If you maxed out at your old job and keep deferring at the new one, you'll over-defer.
- Before Dec 31: tell the new employer your YTD deferrals from the previous job and cap what's left.
- After Dec 31: notify one plan by March 1 and withdraw the excess (and its earnings) by April 15. Miss that deadline and the excess is taxed twice — once in the contribution year, once when eventually distributed.
Related: the same shared-limit rule applies to Solo 401(k)s — see the Solo 401(k) guide.
Reset Your W-4 (and Do Step 2 for Overlapping Jobs)
A new job means a new W-4. If your old and new jobs overlap — or you're married filing jointly and your spouse also works — use one of the three Step 2 methods on Form W-4 (2026): (a) the IRS Tax Withholding Estimator; (b) the Multiple Jobs Worksheet, with the extra withholding it produces entered in Step 4(c) of the highest-paying job's W-4 only; or (c) the two-jobs checkbox, which must be checked on both W-4s. Skip Step 2 and you'll likely be under-withheld and owe at filing (possibly with an underpayment penalty).
Run the numbers in the W-4 Calculator or the Take-Home Pay Calculator.
Additional Medicare (0.9%) — a quieter trap
Each employer only starts withholding Additional Medicare above $200,000 of that job's wages. Your liability is on combined wages and self-employment income above $200,000 (single, head of household, qualifying surviving spouse), $250,000 (married filing jointly, counting both spouses) or $125,000 (married filing separately), so a job-switcher can be under-withheld here even with two moderate salaries. Adjust your W-4 or set aside cash for the shortfall.
Mid-Year Job-Change Checklist
- ☐File a new W-4 with the new employer; if jobs overlap, use one Step 2 method (the two-jobs box goes on both W-4s; the worksheet amount goes on the highest-paying job's W-4 only).
- ☐Tell the new 401(k) administrator your YTD deferrals from the old plan.
- ☐Note both W-2 Box 4 amounts — if combined > $11,439 (2026), you have an excess SS credit.
- ☐Confirm HSA/FSA elections at the new job (limits are also per-person).
- ☐Roll or leave the old 401(k) — cashing it out means income tax, plus a 10% additional tax if you're under 59½ and no exception applies (leaving your job in or after the year you turn 55 is one — and it only works while the money stays in that plan, so don't roll it to an IRA first if you might need it).
- ☐Update address with old employer so the W-2 arrives in January.
- ☐If income spikes, consider Q4 estimated tax to avoid an underpayment penalty.
FAQ
Both jobs withheld Social Security — do I get it back?
Yes, if the excess came from MULTIPLE employers. Your combined Social Security withheld across all W-2s minus the per-person maximum (2026: $11,439) flows onto Schedule 3, line 11 as a credit. Your tax software claims it automatically when you enter both W-2s — no separate form to file.
Does the 401(k) contribution limit reset with a new employer?
No. The elective deferral limit ($23,500 in 2025 / $24,500 in 2026, plus catch-ups) applies PER PERSON across all employers combined. If you maxed out at your old job and start deferring at the new one, you'll over-contribute. Notify the new payroll team, or withdraw the excess by April 15 to avoid double taxation.
Do I need a new W-4 at every job change?
Yes. A new job means a new W-4. If you hold two jobs at the same time (or you're married filing jointly and your spouse also works), use one Step 2 method: (a) the IRS Tax Withholding Estimator; (b) the Multiple Jobs Worksheet, with its extra withholding entered in Step 4(c) of the highest-paying job's W-4 only; or (c) the two-jobs checkbox, which must be checked on both W-4s. Skip Step 2 and you'll likely be under-withheld and owe at filing.
What if only ONE employer over-withheld Social Security?
Schedule 3 does NOT apply. You must ask that employer for a corrected W-2 (Form W-2c) and a refund of the over-withholding. If they refuse, file Form 843 with a written statement from the employer showing they won't refund it.
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Sources & References
Primary references used for this content
Excess Social Security and Tier 1 RRTA tax withheld
Multi-employer refund via Schedule 3; one-employer W-2c fix.
View on irs.gov
Additional Credits and Payments
Line 11 — excess Social Security and Tier 1 RRTA tax withheld.
View on irs.gov
Tax Withholding and Estimated Tax
Multiple-job withholding and W-4 Step 2.
View on irs.gov
2026 Social Security Changes
OASDI wage base $184,500 for 2026.
View on ssa.gov
✓4 primary sources; links re-checked on a weekly rotation by the source watcher
Disclaimer: This calculator provides estimates for educational purposes only. Not tax, legal, or financial advice. Results may vary based on your specific circumstances. Consult a qualified CPA or tax professional for personalized guidance.