What is FICA OASDI on My Paycheck?
August 25, 2026
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What is FICA OASDI on My Paycheck What Is FICA OASDI on My Paycheck? (2026 Guide) | ADP Salary Calculator Pay Stub Glossary · Updated
⚡ Quick Answers
Where it appears
Deductions/benefits section, with a YTD total
2026 contribution limit
$24,500 (under 50)
2026 catch-up (age 50+)
Extra $8,000 ($11,250 for ages 60–63)
New in 2026
High earners’ catch-up must be Roth
Your 401(k) contributions generally appear as a pre-tax or post-tax deduction itemized under the deductions or benefits section of your pay stub. It lists the amount taken from your current paycheck alongside a year-to-date (YTD) cumulative total — but depending on your plan and your income, you may actually see more than one 401(k)-related line, especially since a significant IRS rule change took effect on January 1, 2026.
This guide covers exactly where and how each type of 401(k) contribution shows up, what the numbers mean, and how to verify them against your retirement account provider. For the rest of your pay stub’s deductions, see our complete payroll deductions guide.
1 The Basics
Where and How It Appears
On nearly every standard pay stub layout, your 401(k) contribution sits in the deductions section (sometimes split into “Pre-Tax Deductions” and “Post-Tax Deductions” subsections) or a dedicated benefits section, depending on your payroll provider’s template.
- It’s shown as a dollar amount for the current pay period
- A separate Year-to-Date (YTD) column tracks your cumulative contributions for the calendar year
- The specific label varies by employer and payroll system, though most use a recognizable variation of “401K”
2 Pre-Tax vs. Roth
Pre-Tax vs. Roth 401(k) on Your Stub
If your employer’s plan offers both contribution types, they’ll appear as two distinct lines, since they’re taxed differently:
401K / 401(k) Pre-Tax / RETTraditional (Pre-Tax) 401(k)
Pre-Tax Deduction
Listed under pre-tax deductions. It reduces your gross taxable income before federal and state income tax are calculated for that pay period — though it does not reduce wages subject to Social Security or Medicare tax.
ROTH 401K / 401(k) RothRoth 401(k)
Post-Tax Deduction
Listed under post-tax or after-tax deductions, because contributions are taken from pay that has already been taxed. It does not reduce your taxable wages for the current year, but qualified withdrawals in retirement are generally tax-free.
💡 Both count toward the same annual limit: Pre-tax and Roth 401(k) contributions share a single combined IRS limit ($24,500 in 2026) — splitting your contributions between the two doesn’t let you contribute more in total, only changes when you pay tax on that money.
3 Employer Match
The Employer Match Line
ER 401K / 401(k) MatchEmployer Match
Informational Only
Frequently shown in a separate “Employer Benefits” or memorandum section. This shows what your company is contributing to your account on your behalf — it does not affect your net take-home pay, since it was never part of your wages to begin with.
⚠️ Don’t confuse this with your own contribution: Your personal contribution line and the employer match line are tracked separately, both toward different IRS limits — your own contributions count toward the $24,500 individual limit, while the combined total of your contributions, the employer match, and any after-tax contributions count toward a separate, higher overall plan limit ($72,000 in 2026 for those under 50).
4 Key Tracking Elements
Three Key Tracking Elements
A well-designed pay stub tracks your 401(k) using three distinct figures, each answering a different question:
| Element | What It Answers |
|---|---|
| Current Period | Exactly how much was deducted from this specific paycheck |
| Year-to-Date (YTD) | Your total contributions saved through payroll since January 1st |
| Adjusted Taxable Gross | Your gross pay minus your pre-tax 401(k) deduction — the lower figure that federal and state income tax are actually calculated on for that pay period |
The “Adjusted Taxable Gross” figure (sometimes labeled “Federal Taxable Wages” or similar) is often overlooked, but it’s the number that explains why increasing your pre-tax 401(k) percentage doesn’t reduce your paycheck dollar-for-dollar — part of that increase is offset by paying less income tax.
5 2026 Limits
2026 Contribution Limits
| Limit Type | 2026 Amount |
|---|---|
| Employee elective deferral limit (under age 50) | $24,500 |
| Standard catch-up contribution (age 50–59, and 64+) | Additional $8,000 |
| “Super” catch-up contribution (ages 60–63 only) | Additional $11,250 (instead of the standard catch-up) |
| Combined employee + employer + after-tax limit (under 50) | $72,000 |
These limits are set annually by the IRS and adjusted for inflation. Once you hit the applicable limit through payroll deductions, your contributions should automatically stop for the remainder of the calendar year — worth confirming on your pay stub as you approach the cap late in the year.
★ New for 2026
New for 2026: Mandatory Roth Catch-Up for High Earners
This is the most significant change to how 401(k) contributions appear on pay stubs in years, and it’s worth understanding even if it doesn’t apply to you yet.
The Rule, Plainly
Effective January 1, 2026, employees age 50 or older whose FICA wages (Box 3 of their W-2) from their employer exceeded $150,000 in the prior calendar year must make any catch-up contributions as Roth (after-tax) — pre-tax catch-up contributions are no longer allowed for this group.
- This is a mandatory provision of the SECURE 2.0 Act, implemented through final IRS/Treasury regulations issued in September 2025
- The $150,000 threshold is based specifically on prior-year FICA wages from that specific employer (not combined income from multiple employers, and not household income)
- The threshold is indexed for inflation and was updated from an originally proposed $145,000 to $150,000 for determining 2026 eligibility
- If your plan doesn’t offer a Roth option and you’re subject to this rule, you may be unable to make any catch-up contributions at all until your employer adds one
- Self-employed individuals without W-2 FICA wages are not subject to this rule
What This Looks Like on a Pay Stub
If you’re affected, your payroll system may now show your catch-up contribution as a separate, distinct line from your regular pre-tax 401(k) deferral — for example, “401(k) Roth Catch-Up” alongside your standard “401(k) Pre-Tax” line — since the two are taxed differently even though they go into the same overall account.
⚠️ If you’re a high earner still seeing pre-tax catch-up contributions in 2026: This may indicate your employer hasn’t yet updated its payroll system for the new requirement. Errors generally need to be corrected by reclassifying the contributions as Roth, which can involve corrected tax forms — worth raising with HR or payroll promptly if you believe you’re affected.
7 After-Tax / Mega Backdoor
After-Tax Contributions & the Mega Backdoor Roth
Some plans allow a third type of contribution beyond standard pre-tax and Roth deferrals: after-tax (non-Roth) contributions, often used as part of a “mega backdoor Roth” strategy for employees who’ve already maxed out their standard $24,500 limit.
401K AFTER-TAXAfter-Tax Contribution
Not Roth, Not Pre-Tax
Reduces your net take-home pay like a post-tax deduction, but is tracked separately from Roth contributions since it has different tax treatment on withdrawal. These contributions fill the space between your $24,500 personal limit and the $72,000 combined plan limit, alongside any employer match.
If your plan allows in-plan conversion or rollover of after-tax contributions to Roth, that conversion is typically handled outside of standard payroll processing and won’t appear as a recurring pay stub line item the way regular contributions do.
8 Auto-Enrollment
Auto-Enrollment and Auto-Escalation
Many employers now automatically enroll new employees into the 401(k) plan at a default contribution rate, then increase (escalate) that rate by a set percentage each year unless the employee opts out or changes it.
- If you were auto-enrolled, you may see a 401(k) deduction on your very first pay stub without having actively signed up
- Auto-escalation means your contribution percentage — and therefore your dollar deduction — may increase automatically on an annual date (often each plan anniversary or the start of the year) even though your pay rate hasn’t changed
- If your 401(k) deduction jumps unexpectedly, checking whether auto-escalation kicked in is a good first troubleshooting step before assuming it’s an error
9 True-Up Contributions
True-Up Contributions
If your employer matches contributions per pay period (rather than on an annual basis) and you max out your personal contribution limit before the last pay period of the year, you could miss out on part of your employer match for those final pay periods. Some plans correct this automatically with a true-up contribution.
💡 Where to look: A true-up, if your plan offers one, typically appears as a separate, one-time employer contribution line shortly after year-end rather than a regular per-paycheck line — worth checking your first pay stub or two of the following year if you maxed out your 401(k) early in the prior year.
10 Worked Example
Worked Example: Reading the Numbers
Scenario: An employee earning $3,000 gross on a biweekly paycheck contributes 8% to a traditional pre-tax 401(k), with a 4% employer match.
💰 Sample Pay Stub — 401(k) Lines
Gross Pay$3,000.00
401(k) Pre-Tax (8%) — Current Period−$240.00
Adjusted Taxable Gross ($3,000 − $240)$2,760.00
401(k) Pre-Tax — YTD (period 14 of 26)$3,360.00
Employer Match (4%) — Current Period$120.00 (informational)
Employer Match — YTD$1,680.00 (informational)
Federal and state income tax for this paycheck are calculated on the $2,760 Adjusted Taxable Gross, not the full $3,000 — but Social Security and Medicare are still calculated on the full $3,000, since traditional 401(k) contributions don’t reduce FICA wages.
11 Verification
How to Verify Your 401(k) Line Against Your Provider
- Log into your retirement plan provider’s portal (Fidelity, Vanguard, Empower, etc.) separately from your payroll portal
- Compare the YTD contribution total shown by your provider against the YTD figure on your most recent pay stub
- Confirm your contribution percentage on file with payroll matches what you intended to elect
- If you’re paid biweekly, remember some months have three pay periods instead of two — a month with an “extra” paycheck will show a larger YTD jump than usual, which is expected, not an error
- Check that the employer match YTD figure on your pay stub is tracking consistently with your provider’s records, accounting for any vesting schedule that applies only to when you can keep the funds, not whether they were deposited
12 Troubleshooting
Troubleshooting a Discrepancy
ISSUEPay stub YTD and provider portal YTD don’t match
LIKELY CAUSE
A short processing delay between payroll and the retirement provider is common and usually resolves within a few business days. A persistent gap of more than one pay period is worth raising with HR or payroll.
ISSUEContribution stopped mid-year unexpectedly
LIKELY CAUSE
You may have hit the annual IRS contribution limit, in which case payroll should automatically stop pre-tax/Roth deferrals for the rest of the year — this is expected behavior, not an error, though it’s worth double-checking against the correct limit for your age group.
ISSUECatch-up contribution shows as pre-tax despite high income
LIKELY CAUSE
If your prior-year FICA wages from this employer exceeded $150,000 and you’re 50 or older, your 2026 catch-up contributions should be Roth by law. If they’re still showing as pre-tax, flag it to payroll — this may require correction.
ISSUEEmployer match line is missing entirely
LIKELY CAUSE
Not every pay stub template displays the employer match as a line item, even if the match is actually being deposited. Check your retirement provider’s portal directly rather than assuming the match isn’t happening just because it’s absent from the stub.
Frequently Asked Questions
401(k) on a Pay Stub — FAQs
How do 401(k) contributions appear on a pay stub?
401(k) contributions generally appear as a line item in the deductions or benefits section of your pay stub, commonly labeled “401K,” “401(k) Pre-Tax,” or “RET.” It shows the dollar amount deducted from your current paycheck alongside a Year-to-Date (YTD) cumulative total for the year.
What is the difference between how pre-tax and Roth 401(k) contributions show up on a pay stub?
Pre-tax (traditional) 401(k) contributions are listed under pre-tax deductions and reduce your taxable wages before federal and state income tax are calculated. Roth 401(k) contributions are listed under post-tax or after-tax deductions, since they’re taken from pay that has already been taxed, and don’t reduce your taxable wages.
Does the employer 401(k) match appear on my pay stub?
Many pay stubs show the employer match in a separate informational section, often labeled “Employer 401(k) Match” or a code like “ER 401K.” This amount is not deducted from your pay and does not affect your net take-home pay — it’s shown for transparency about your total compensation.
What is the new mandatory Roth catch-up rule for 2026?
Starting January 1, 2026, employees age 50 or older whose prior-year FICA wages (Box 3 of their W-2) from their employer exceeded $150,000 must make any catch-up contributions as Roth (after-tax) rather than pre-tax. This is a mandatory provision of the SECURE 2.0 Act, and affected employees may see their catch-up contributions split into a separate Roth-designated line on their pay stub.
What is “Adjusted Taxable Gross” on a pay stub?
Adjusted Taxable Gross refers to your gross pay minus your pre-tax deductions, including pre-tax 401(k) contributions. This lower figure is what federal and state income tax are actually calculated on for that pay period, which is why your income tax withholding is based on a smaller number than your full gross pay.
Do 401(k) contributions reduce Social Security and Medicare tax?
No. Traditional 401(k) contributions reduce your federal and state taxable wages, but they’re still included in wages subject to Social Security and Medicare (FICA) tax. This is different from pre-tax health insurance premiums, which typically reduce the FICA wage base as well.
Why did my 401(k) contribution amount change without me doing anything?
This is commonly caused by auto-escalation, where your employer’s plan automatically increases your contribution percentage by a set amount each year (often on your enrollment anniversary or at the start of the calendar year) unless you opt out. It can also happen if you crossed an IRS contribution limit and deductions adjusted or stopped automatically.
Sources & Further Reading
- IRS retirement plan contribution limits for 2026 (401(k), 403(b), and related plans)
- IRS/Treasury final regulations implementing SECURE 2.0 Act Section 603 (mandatory Roth catch-up contributions), issued September 2025
- IRS guidance on FICA wage reporting (Form W-2, Box 3) as the basis for the $150,000 Roth catch-up threshold
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