W-2 Box 1 vs. Your Last Pay Stub: How to Reconcile the Two Line by Line
Box 1 is taxable wages, not gross pay. Run the TY 2026 reconciliation ladder from your final stub's YTD gross to W-2 Box 1, line by line.
Disclaimer: Informational only, not tax, legal, or financial advice. Rules and rates can change; check current IRS/state guidance or consult a professional.
Your W-2 arrived and Box 1 is thousands of dollars below the year-to-date gross on your December stub. Nothing is missing. The two documents are measuring different things, and once you see the arithmetic, the gap usually explains itself in about five minutes.
This guide walks the reconciliation both directions: stub down to Box 1 when the W-2 is lower, and stub up to Box 1 when it is higher. Every figure below is labeled with its tax year, because a reader holding a TY 2026 W-2 in January 2027 is one careless number away from using a TY 2025 limit.
Quick Answer: Why Box 1 Is Lower Than Your Last Pay Stub
Your final pay stub reports gross wages. Box 1 reports taxable wages, which is gross minus everything the tax code lets you exclude from federal income tax.
Box 1 = final stub YTD gross − pre-tax deductions + imputed income
Pre-tax deductions include traditional 401(k) deferrals, Section 125 medical, dental and vision premiums, health and dependent-care FSA contributions, pre-tax HSA contributions, and qualified transit benefits.
If you have never separated those two ideas, gross pay vs. net pay covers the foundation. Box 1 sits between them: less than gross, more than what hit your bank account.
The Reconciliation Ladder: Stub YTD Gross to Box 1
Pull the last stub dated in the tax year, not the last period you worked. Find the YTD column, then run the ladder.
| Step | Line | Effect on Box 1 |
|---|---|---|
| Start | Final stub YTD gross | Starting figure |
| Subtract | Section 125 medical, dental, vision premiums | Lowers Box 1 |
| Subtract | Health FSA and dependent-care FSA | Lowers Box 1 |
| Subtract | Pre-tax HSA run through payroll | Lowers Box 1 |
| Subtract | Traditional 401(k), 403(b), or 457(b) deferrals | Lowers Box 1 |
| Subtract | Qualified pre-tax parking and transit | Lowers Box 1 |
| Add | Imputed income (group-term life over $50,000, company car, domestic-partner coverage) | Raises Box 1 |
| Add | Taxable third-party sick pay reported by the employer | Raises Box 1 |
| Result | W-2 Box 1 | Should match to the cent |
A worked TY 2026 example
Maya works hourly for one employer. Her final stub of TY 2026 is dated 12/24/2026.
- YTD gross: $62,400.00
- Section 125 medical and dental: −$3,120.00
- Limited-purpose FSA (dental and vision): −$1,200.00
- Pre-tax HSA via payroll: −$2,000.00
- Traditional 401(k) at 6%: −$3,744.00
- Group-term life over $50,000, imputed: +$186.00
- Box 1 = $52,522.00
Maya’s FSA is limited-purpose because a general-purpose health FSA would disqualify her from contributing to an HSA at all. Every one of her TY 2026 elections sits inside the TY 2026 ceilings: the $24,500 elective deferral limit, the $4,400 self-only HSA limit, and the $3,400 health FSA limit, which limited-purpose FSAs share. If your own YTD figure exceeds one of those TY 2026 ceilings, that is a separate problem worth raising with payroll.
Now do Box 3 and Box 5
Most reconciliations fall apart right here, because the 401(k) comes back.
Maya’s Social Security wages (Box 3) and Medicare wages (Box 5) are $62,400 − $3,120 − $1,200 − $2,000 + $186 = $56,266.00. Her deferrals never left FICA wages, so they are not subtracted here.
From there the withholding boxes are pure multiplication. Box 4 = 6.2% × $56,266 = $3,488.49. Box 6 = 1.45% × $56,266 = $815.86. Those two rates did not change between TY 2025 and TY 2026.
| Deduction | Reduces Box 1 | Reduces Box 3 | Reduces Box 5 |
|---|---|---|---|
| Traditional 401(k), 403(b), 457(b) | Yes | No | No |
| Section 125 medical, dental, vision | Yes | Yes | Yes |
| Health FSA and dependent-care FSA | Yes | Yes | Yes |
| Pre-tax HSA through payroll | Yes | Yes | Yes |
| Roth 401(k) | No | No | No |
| Union dues, garnishments, 401(k) loan repayment | No | No | No |
Comparing Box 1 to Box 3 is often faster than comparing Box 1 to your stub. If Box 3 exceeds Box 1, the difference is almost always your traditional 401(k) for the year, which is the same number printed in Box 12 with Code D.
Two ceilings shape the high end. Box 3 stops at the Social Security wage base, which is $184,500 for TY 2026 (it was $176,100 for TY 2025). Box 5 has no cap at all, and once wages from one employer pass $200,000, that employer withholds the extra 0.9% Additional Medicare Tax on the excess. If the 6.2% and 1.45% mechanics are new to you, FICA tax explained breaks them down.
Pre-Tax Deductions That Shrink Box 1 (and the Ones That Don’t)
Not every deduction on your stub is pre-tax, and the ones that are do not all behave the same way. How pre-tax deductions affect your paycheck covers the paycheck-level mechanics; here is what matters for the W-2.
Traditional 401(k), 403(b), and 457(b) deferrals. Out of Box 1, still in Boxes 3 and 5. The TY 2026 elective deferral limit is $24,500, with an $8,000 catch-up at age 50 and older and an $11,250 catch-up for ages 60 through 63. The TY 2025 limit was $23,500. If your Box 12 Code D figure is above the TY 2026 limit that applies to you, call payroll.
Section 125 cafeteria-plan premiums. Medical, dental, and vision premiums withheld pre-tax leave all three wage boxes. This is usually the largest single line in the ladder for a worker with family coverage.
Health FSA. The TY 2026 maximum election is $3,400, up from $3,300 for TY 2025, with a carryover maximum of $680 for TY 2026.
Dependent-care FSA. The TY 2026 exclusion jumped to $7,500 ($3,750 if married filing separately), up from $5,000 for TY 2025. Your election also shows in Box 10.
Pre-tax HSA through payroll. TY 2026 limits are $4,400 self-only and $8,750 family, plus a $1,000 catch-up at 55 and older. TY 2025 was $4,300 and $8,550.
The Roth trap
A Roth 401(k) contribution shows up on your stub as a deduction and does nothing to Box 1. It is after-tax money. If you switched from traditional to Roth partway through the year, only the traditional portion belongs in the ladder, and your gap will look exactly like the size of your Roth contributions.
Post-tax life insurance, union dues, wage garnishments, and 401(k) loan repayments behave the same way. They shrink your deposit, not your taxable wages.
One correction worth knowing
A common claim about Box 12 Code W (HSA contributions) is that it covers only what your employer put in. It does not. Code W includes employer contributions and the amounts you elected to contribute through a Section 125 cafeteria plan, per the IRS instructions for Forms W-2 and W-3. Do not treat your own payroll HSA contributions as missing because they are bundled into Code W.
When Box 1 Is Higher Than Your Stub: Imputed Income and Timing
Box 1 above your YTD gross feels alarming and is usually routine. Two causes account for nearly all of it.
Imputed income
Imputed income is the taxable value of a benefit you received without cash changing hands. It is added to Boxes 1, 3, and 5 even though it never appeared as earnings on a stub you cashed.
Common sources: employer-paid group-term life insurance covering more than $50,000 (reported in Box 12 with Code C), personal use of a company vehicle, health coverage for a domestic partner who is not a tax dependent, taxable third-party sick pay, and gift cards or cash-equivalent awards.
Box 12 Code DD, the cost of employer-sponsored health coverage, is a different animal. It is informational only. Do not subtract it from anything.
The pay-date rule
Wages land on the W-2 for the year they were paid, not the year they were worked. That is constructive receipt, and it is the single most common source of confusion for weekly and biweekly hourly workers.
Hours worked the last week of December 2026 and paid on January 2, 2027 belong on the TY 2027 W-2. Your December 2026 stub may show them as earned; the TY 2026 W-2 will not. Some years a weekly schedule produces 53 pay dates and a biweekly schedule produces 27, which shifts an entire extra check into one W-2 year.
The last stub you hold may also pre-date year-end work. Late bonuses, imputed-income true-ups, and manual corrections posted after the final regular payroll show up on the W-2 and on no stub at all.
This is where an independent record earns its keep. ClockWage44 logs your shifts per job and resolves federal tax, state tax, FICA, overtime, and deductions into a take-home figure on-device, so you have your own ledger of hours and gross to compare against instead of one employer PDF. It does not produce or import a W-2; it just means you are not reconciling from memory.
New on the TY 2026 W-2: Box 12 Codes TT and TP
TY 2026 is the first W-2 to carry the One Big Beautiful Bill reporting codes, and they trip people up immediately.
Code TT: qualified overtime compensation. This reports only the FLSA half-time premium, meaning the extra 0.5x on hours over 40, not the full 1.5x overtime wage. A worker who earned $9,000 of gross overtime pay sees roughly $3,000 in Code TT.
Code TP: cash tips reported to your employer.
Neither code reduces Box 1, Box 3, or Box 5. Both are informational figures that feed above-the-line deductions you claim on your Form 1040. The TY 2026 caps are $12,500 for single and head of household filers and $25,000 for joint filers on the overtime deduction, and $25,000 per return on the tips deduction. Married filing separately is not eligible for either.
Do not subtract TT or TP from Box 1 while reconciling. Your overtime and tips are already fully inside Box 1, exactly as they should be. The details are in the No Tax on Overtime deduction and the No Tax on Tips deduction.
Is It an Error? What to Check and How to Get a W-2c
Run the ladder first. If it balances, you are done; if it does not, work this list.
- Unexplained gap after the ladder balances everything else. Ask payroll to identify the difference before assuming the form is wrong.
- Box 1 above your YTD gross with no imputed-income line anywhere. Worth a question.
- Box 3 above $184,500 on a TY 2026 W-2. That exceeds the wage base for a single employer and is a genuine error.
- Box 12 Code D that does not match your YTD 401(k) deferrals. One of the two records is wrong.
- Box 2 that does not match your YTD federal withheld. If it also looks too low for your income, a paycheck checkup is the follow-up.
- Box 4 that is not 6.2% of Box 3, or Box 6 that is not 1.45% of Box 5. These are mechanical and should tie out within rounding.
The escalation path
Start with your employer. Most W-2 problems are a data-entry fix, and the correction vehicle is Form W-2c, which the employer files along with a Form W-3c.
If you do not have a corrected form by the end of February, call the IRS at 800-829-1040 and the IRS will contact your employer directly. If the filing deadline arrives with no W-2c in hand, you can file using Form 4852 as a substitute, built from your final pay stub.
Two situations that look like errors and are not
Multiple jobs. You get one W-2 per employer, and each one reconciles separately against that employer’s stubs. Box 3 is capped per employer, not per person, so two jobs can over-withhold Social Security across the year. That excess is recoverable as a credit when you file. Filing taxes with multiple jobs walks through it.
Box 16 that differs from Box 1. States do not all follow the federal exclusions. California and New Jersey, for example, do not recognize the HSA exclusion, so state wages run higher than federal wages on the same form.
Related Reading
- How to Read a Pay Stub: Line-by-line on the YTD columns you need for the ladder
- Take-Home Pay Calculator: See how pre-tax deductions move gross, taxable, and net pay
- 401(k) Paycheck Impact Calculator: Model what a deferral change does to taxable wages
- HSA and FSA Paycheck Impact Calculator: Section 125 contributions against all three wage boxes
- FICA Tax Calculator: Check Box 4 and Box 6 against Box 3 and Box 5
References
- IRS General Instructions for Forms W-2 and W-3: Box 1, 3, and 5 definitions, the full Box 12 code list, and the pay-date reporting rule.
- IRS Publication 15-B, Employer’s Tax Guide to Fringe Benefits: Group-term life over $50,000, imputed income, and cafeteria-plan treatment.
- IRS Tax Topic 751: Social Security and Medicare withholding rates and the annual wage base.
- IRS Tax Topic 154: What to do if your W-2 is incorrect or never arrives.
- IRS About Form W-2c: The corrected wage and tax statement your employer files.
- IRS About Form 4852: Substitute for Form W-2 when no correction arrives in time.
- IRS: 401(k) limit increases to $24,500 for 2026: TY 2026 retirement contribution limits.
- IRS Publication 969: HSA contribution limits and qualifying rules.
Frequently Asked Questions
Why is Box 1 on my W-2 lower than the gross pay on my last pay stub?
Box 1 is taxable wages, not gross wages. Pre-tax deductions (traditional 401(k), Section 125 medical, dental and vision, health and dependent-care FSA, pre-tax HSA) come out before Box 1 is calculated. Subtract them from your final stub's YTD gross and you should land on Box 1.
Does my 401(k) reduce Box 1 on my W-2?
A traditional pre-tax 401(k) deferral reduces Box 1 but not Box 3 or Box 5, because deferrals are still Social Security and Medicare wages. A Roth 401(k) deferral is after-tax and reduces nothing. Your total deferrals appear in Box 12 with Code D. The TY 2026 elective deferral limit is $24,500, plus $8,000 more if you are 50 or older.
Why are Box 1, Box 3, and Box 5 all different numbers?
Different deductions hit different boxes. A traditional 401(k) reduces Box 1 only. Section 125 premiums and pre-tax HSA contributions reduce all three. Box 3 is capped at the Social Security wage base ($184,500 for TY 2026, $176,100 for TY 2025), while Box 5 has no ceiling, so a high earner sees Box 3 well below Box 5.
Why is Box 1 higher than my year-to-date gross?
Imputed income. Group-term life coverage over $50,000 (Box 12 Code C), personal use of a company vehicle, domestic-partner health coverage, and taxable third-party sick pay all add to Box 1 without ever hitting your bank account. Some employers post these after the last regular payroll of the year, so they never appear on a stub you hold.
Do hours I worked in December but got paid for in January count on this year's W-2?
No. Wages are reported for the year they are paid, not the year they are earned. A check dated January 2, 2027 belongs on the TY 2027 W-2 even if every hour on it was worked in December 2026.
What are Box 12 Codes TT and TP on my TY 2026 W-2?
They are new for tax year 2026. Code TT reports qualified overtime compensation, meaning only the FLSA half-time premium and not the full overtime wage. Code TP reports cash tips you reported to your employer. Neither reduces Box 1. They are the figures you use to claim the No Tax on Overtime and No Tax on Tips deductions on your return.
My W-2 still doesn't reconcile. Is it a payroll error?
Possibly. Run the ladder first, then check the mechanical relationships: Box 4 should be 6.2% of Box 3, Box 6 should be 1.45% of Box 5, and for TY 2026 Box 3 should not exceed $184,500. If those hold and you still have an unexplained gap, ask payroll to walk you through the difference before assuming the form is wrong.
How do I get my W-2 corrected?
Ask your employer to issue a Form W-2c. If you do not have a corrected form by the end of February, call the IRS at 800-829-1040 and they will contact your employer. If the filing deadline arrives with no W-2c, file using Form 4852 with your final pay stub as the basis.