Workers who had more than one employer last year may be due cash back at tax time if too much Social Security Tax or railroad retirement withholding came out of their paychecks. The Internal Revenue Service allows refunds when combined withholding crosses the legal maximums, and different rules apply depending on whether the money was taken for Social Security, Tier 1 RRTA tax, or Tier 2 RRTA. The process hinges on which tax was overwithheld and whether one employer or several caused the overage, according to guidance reinforced this filing season.
Policy overview

Most employers must withhold Social Security Tax on wages up to the annual Social Security wage base. Railroad employers withhold both Tier 1 RRTA tax and Tier 2 RRTA:
- Tier 1 RRTA works like Social Security and Medicare, providing equivalent benefits and using the same wage base as Social Security.
- Tier 2 RRTA funds a separate, pension-style benefit for railroad workers and uses its own wage base.
When a worker’s combined wages from two or more employers hit these limits, the total withheld may exceed what is actually due for the year.
- Excess Social Security or Tier 1 RRTA tax withheld because of multiple employers is refundable on the annual tax return. Taxpayers claim it on Schedule 3 (Form 1040), which flows into the main refund calculation.
- Excess Tier 2 RRTA withholding cannot be claimed on the return. Workers must submit a separate request using Form 843, Claim for Refund and Request for Abatement.
If a single employer withheld too much of any of these taxes, that employer is supposed to fix it by adjusting payroll records and issuing a corrected form. If the employer won’t or can’t make the adjustment, the worker can ask the IRS for a refund using Form 843.
When spouses file a joint return, each must compute any excess Social Security or Tier 1 RRTA amount separately, since the limits apply to each person’s wages, not to the couple as a unit.
Important boundary: all wages are subject to Medicare tax. Medicare has no wage base, so there is no “excess” Medicare withholding in these situations. In short, while Social Security and Tier 1 RRTA have caps, Medicare does not.
How to claim a refund and what to expect
For excess Social Security or Tier 1 RRTA tax due to having two or more employers:
- Report the excess on Schedule 3 (Form 1040) and attach it to the federal return.
- The form is available on the IRS website: Schedule 3 (Form 1040).
- Keep W‑2s from all employers to show total wages and the Social Security or Tier 1 RRTA amounts withheld.
For excess Tier 2 RRTA due to having two or more railroad employers:
- File Form 843 with the IRS: Form 843, Claim for Refund and Request for Abatement.
- Include copies of relevant W‑2s and a short explanation that the combined Tier 2 RRTA withholding exceeded the annual limit because of multiple railroad employers.
For a single-employer error (any of Social Security, Tier 1 RRTA, or Tier 2 RRTA):
- Ask the employer to correct the overcollection and issue corrected payroll forms.
- If the employer does not fix it, submit Form 843 to the IRS with supporting documents.
The Railroad Retirement Board and the IRS coordinate on these issues to help ensure workers get proper credit and refunds. For background on how railroad retirement taxes support benefits, see the Railroad Retirement Board’s official information page: U.S. Railroad Retirement Board.
Common scenarios and mistakes
Tax professionals say common scenarios drive these overpayments:
- A worker changes jobs midyear and the second employer begins withholding Social Security immediately, unaware the worker already hit the wage base at the first job.
- A railroad employee picks up work with a second railroad, and both employers withhold Tier 2 RRTA against separate wage bases.
These are normal payroll outcomes under the law, and the IRS refund process is designed to square things up at filing time.
According to analysis by VisaVerge.com, filers often mix up the proper paths:
- Some try to claim excess Tier 2 RRTA on the tax return (which is incorrect).
- Others incorrectly file Form 843 for excess Social Security (also incorrect).
Clean divide:
- Use the tax return and Schedule 3 for Social Security or Tier 1 RRTA overages from multiple employers.
- Use Form 843 for Tier 2 RRTA overages and for any single-employer errors that aren’t corrected by payroll.
Practical steps to reduce problems
Workers can reduce headaches by reviewing year-to-date withholding after any job change. Suggested actions:
- Verify totals against the Social Security wage base shown in IRS publications for the tax year.
- Confirm whether your railroad pay triggered Tier 2 RRTA withholding and whether the combined Tier 2 amount from more than one railroad employer went over the annual limit.
- If an employer made a mistake and won’t correct it, gather written proof of your request and the employer’s response to include with Form 843.
- If you work in the railroad industry, ask payroll which portion is Tier 1 RRTA (the Social Security–equivalent part) and which is Tier 2 RRTA (the pension part).
- Keep all pay stubs and W‑2s. For joint filers, remember each spouse checks their own wage base separately.
Why accuracy matters
Because RRTA tax includes both Tier 1 and Tier 2 layers, precision matters:
- Tier 1 RRTA follows Social Security and Medicare rules, including the wage base cap that leads to refunds when multiple employers are involved.
- Tier 2 RRTA is a separate pension contribution with its own cap and its own refund pathway.
Filing the right form speeds processing and reduces IRS follow-up. Remember: Medicare applies to all wages, so you cannot claim back Medicare withholding under these rules. That is why workers often see a refund of excess Social Security or Tier 1 RRTA but no change to Medicare totals.
For railroad employees who move between carriers, timing can complicate records. Make sure both employers properly code Tier 1 and Tier 2 on the W‑2. If codes or amounts look off, request a corrected form before filing. For everyone else, when in doubt about whether you hit the wage base with two or more employers, add the Social Security boxes from each W‑2; any excess over the maximum is what you claim on Schedule 3.
The IRS structures these rules to protect workers who pay in through more than one paycheck. With the right form and documentation, most people can recover excess withholding tied to multiple employers or get relief when a single employer won’t fix an error.
A few final practical tips:
- Verify totals against the Social Security wage base for the tax year.
- Confirm Tier 2 RRTA treatment and combined totals if you worked for more than one railroad.
- Keep written records of requests to employers and their responses if payroll corrections are needed.
With the right documentation and the appropriate form—Schedule 3 for Social Security/Tier 1 RRTA overages from multiple employers or Form 843 for Tier 2 RRTA or unresolved single‑employer errors—most taxpayers can recover excess withholding.
This Article in a Nutshell
Workers with multiple employers may have excess Social Security or Tier 1 RRTA withholding when combined wages exceed annual wage bases. Excess Social Security and Tier 1 RRTA withholding resulting from multiple employers is refundable on the federal return by reporting the excess on Schedule 3 (Form 1040) and attaching W‑2s from all employers. Excess Tier 2 RRTA withholding cannot be claimed on the tax return; taxpayers must file Form 843 with supporting W‑2s and an explanation. If a single employer overwithheld, the employer should correct payroll records and issue corrected forms; if they do not, the worker can seek a refund using Form 843. Medicare withholding has no wage base and is not refundable under these rules. Proper documentation and verifying wage bases after job changes reduce errors and speed refunds.