Most physicians read exactly two numbers on a pay stub: the net deposit and, if the month was unusual, the gross. Everything between those two lines is treated as machinery that presumably works. It mostly does. But payroll for an attending is not simple payroll — it carries a wage base that stops mid-year, a surtax that starts mid-year, two contribution limits that have to be paced across the calendar, and a set of premium lines whose tax treatment was chosen by someone in benefits administration who was not thinking about your situation. Each of those has a characteristic failure mode, and each failure is worth between several hundred and several thousand dollars.
This is a ten-minute audit, run once a quarter, line by line. Pull the most recent stub, ideally one with year-to-date columns, and work down it. If you want the underlying anatomy of a stub before you audit yours, the paycheck-decoded module walks the structure.
Start with gross versus contract, per period, in arithmetic
Divide your contractual base salary by the number of pay periods in the year and compare it against the gross on a normal stub. Twenty-four semi-monthly periods and twenty-six biweekly periods are not the same denominator, and a physician who assumes biweekly on a semi-monthly schedule will conclude something is wrong when nothing is.
A physician on $320,000 base paid semi-monthly should see gross pay of $320,000 ÷ 24 = $13,333.33 in a period with no stipend, differential, or productivity settlement. If the number differs, the explanation should be nameable on the stub itself. Unexplained variance in base is the single most common finding of this audit, and it compounds silently: an error of $200 per period is $4,800 by year end.
Check the year-to-date gross against your period count as well. Any drift between per-period arithmetic and the year-to-date column means something was added or removed in a period you did not review.
Federal withholding: check it with the estimator, not with the tables
Do not attempt to verify federal income tax withholding by hand against the published tables. The percentage method annualizes each period, treats supplemental wages differently from regular wages, and interacts with every entry on your Form W-4. Recomputing it manually is a way to generate false alarms.
The shortcut is the IRS Tax Withholding Estimator on irs.gov. Enter the year-to-date figures from the stub and your projected full-year income, and it returns a projected balance due or refund. What you are looking for is not precision but magnitude. A projected result within a few thousand dollars either way is normal. A projected shortfall of $15,000 means the W-4 does not reflect your actual situation, which is common for physicians in the transition year, for two-income households, and for anyone with meaningful or investment income. The fix is Step 4(c) of the W-4, and the deeper treatment is in the physician paycheck withholding guide.
The FICA lines, and the mid-year stop almost nobody verifies
This is the section that repays the audit. Three separate taxes appear here, and they behave differently.
Social Security (OASDI), 6.2 percent, with a ceiling. For 2026 the taxable wage base is $184,500 (IRS Topic No. 751). Above that, the 6.2 percent stops for the year. This is the check almost nobody performs: on a physician salary, the wage base is reached mid-year, and the OASDI line on your stub is supposed to shrink to a partial amount in one period and then go to zero for the rest of the calendar year. If it keeps withholding 6.2 percent in October, that is not a rounding artifact, it is money.
Medicare, 1.45 percent, with no ceiling. It applies to every dollar of covered wages, all year, with no stop (IRS Topic No. 751). A Medicare line that goes to zero is the error.
Additional Medicare Tax, 0.9 percent. An employer must begin withholding this once wages from that employer exceed $200,000 in the calendar year, without regard to your filing status. The 0.9 percent has no , and the statutory thresholds — $200,000, $250,000 married filing jointly, $125,000 married filing separately — are not indexed for inflation (26 U.S.C. §3101(b)(2)).
Example calculation
Assumptions: $320,000 base salary, semi-monthly (24 periods), $13,333.33 per period, single employer, no other wages.
Social Security stop: $184,500 ÷ $13,333.33 = 13.84 periods Through period 13, year-to-date wages = $173,333.33; OASDI withheld = $826.67 per period Period 14 is the partial: $184,500 − $173,333.33 = $11,166.67 taxable, so OASDI = $11,166.67 × 6.2% = $692.33 Periods 15 through 24: OASDI = $0.00 Full-year OASDI = $184,500 × 6.2% = $11,439.00
Additional Medicare Tax start: $200,000 ÷ $13,333.33 = exactly 15 periods, so the 0.9% line first appears in period 16 Full-year surtax withheld = ($320,000 − $200,000) × 0.9% = $1,080.00
Full-year Medicare = $320,000 × 1.45% = $4,640.00, every period, no stop
Two of those events happen within three pay periods of each other, and both are visible on the stub. Confirm the stop happened, confirm the surtax started, and confirm Medicare never stopped.
If OASDI is still being withheld at 6.2 percent after your year-to-date wages pass $184,500, your employer is over-collecting, and a single employer that fails to stop must correct it through its own payroll filings rather than leaving you to recover it at tax time.
The separate case worth knowing: if you hold two unrelated employers in the same year, each applies the wage base independently and neither is doing anything wrong. That over-withholding is recoverable by you, as a credit for excess Social Security tax on your Form 1040. One employer failing to stop is an error. Two employers each stopping correctly is arithmetic.
State and local: confirm the jurisdiction, not just the amount
The verification here is short but consequential. Confirm the state on the stub is the state whose tax you actually owe, and that any local or municipal tax line matches where you work or live under that locality's rules. Physicians who moved mid-year, who work across a state line, or who cover shifts at a site in another jurisdiction are the population where this line goes wrong. A wrong-state withholding is not lost money, but it means filing in two states to move it, which is a real cost in time and preparation fees.
Retirement deferral pacing, and the front-loading trap
For 2026 the elective deferral limit under §402(g) is $24,500, and the overall §415(c) annual additions limit is $72,000 (IRS Notice 2025-67). Take your year-to-date deferral, divide by the number of periods elapsed, multiply by your total periods, and see where you land.
Landing short is easy to fix. Landing early is the trap. If your plan matches per pay period and does not have a true-up provision, front-loading your deferrals means you stop contributing in the fall, and a match that is calculated per period has nothing to match against for the rest of the year.
Important
A physician deferring $2,000 per period against a match of 50 percent of the first 6 percent hits $24,500 partway through period 13. Periods 14 through 24 produce no deferral and therefore no match. At $13,333.33 per period, the forgone match runs roughly $400 per period for eleven periods plus a partial period, on the order of $4,550 of employer money left behind — entirely because of pacing, not because of any contribution decision.
The determining fact is whether your plan has a true-up, which retroactively pays the match you would have received had you contributed evenly. Do not ask a colleague. Read the summary plan description, which your employer must furnish on request, and search it for "true-up" or for the match calculation period. If the match is computed on an annual basis, front-loading costs nothing. If it is computed per payroll period with no true-up, pace your deferrals to $24,500 ÷ 24 = $1,020.83 per period and take the whole match. The retirement account map module covers what to do with capacity beyond §402(g).
HSA pacing, on the same logic
If you are covered by a qualifying high-deductible health plan, the 2026 contribution limits are $4,400 self-only and $8,750 family (IRS Rev. Proc. 2025-19), with an additional $1,000 catch-up at age 55 and older. Contributions routed through payroll under a cafeteria plan avoid Social Security and Medicare tax in addition to income tax, which contributions made directly do not. That payroll-routing advantage is a reason to pace through the stub rather than write a check in April.
Per period, that is $4,400 ÷ 24 = $183.33 self-only, or $8,750 ÷ 24 = $364.58 for family coverage. If your employer contributes as well, employer contributions count against the same limit, so subtract them before setting your own election.
Pre-tax and post-tax premiums, and the disability line that should be post-tax
Insurance premium lines fall into two groups, and the stub usually distinguishes them.
Health, dental, and vision premiums are typically deducted pre-tax through a §125 cafeteria plan. Section 125 provides that no amount is included in a participant's gross income solely because the participant may choose among the plan's benefits (26 U.S.C. §125(a)), which is what allows a salary reduction for premiums to escape income tax and payroll tax. If your health premium is being deducted post-tax, you are paying more than you need to and it is worth asking benefits administration why.
Disability is the exception, and the exception is usually deliberate. IRS Publication 525 (2025) states the governing rule directly: if you paid the premiums on an accident or health insurance policy, the benefits you receive under the policy are not taxable. Employer-paid premiums, or premiums you pay with pre-tax dollars, flip that — the benefit becomes taxable income at the moment you are disabled and least able to absorb a tax bill.
Paying a disability premium with after-tax dollars is not an administrative oversight; it converts a taxable benefit into a tax-free one, and for a physician a tax-free benefit is worth roughly a third more than the same nominal benefit taxed at attending marginal rates.
So the audit question is not whether the disability premium is post-tax, but whether it is post-tax on purpose. If your employer pays the group long-term disability premium entirely, the benefit will generally be taxable, and some plans offer an election to have the employer-paid premium treated as taxable income to you now in exchange for a tax-free benefit later. That election is usually available only during open enrollment.
The error list, ranked by what it costs
Run the audit and triage findings in this order.
- Critical — Social Security withholding that did not stop at $184,500. Direct over-collection, recurring every period until fixed, and the correction path runs through your employer.
- Critical — wrong state or locality. Not lost money, but it forces multi-state filing and can produce underpayment exposure in the correct state.
- Critical — base gross that does not reconcile to contract arithmetic. Every period it persists, it compounds, and the escalation path is documented in the payroll errors article.
- Important — deferral pacing that will exhaust §402(g) early under a per-period match with no true-up. Costs employer money, entirely preventable, fixable only prospectively.
- Important — projected federal withholding shortfall large enough to threaten a safe harbor. Fixable at any point in the year through Step 4(c).
- Important — health premiums deducted post-tax. A quiet, recurring overpayment of income and payroll tax.
- Worth checking — disability premium tax treatment. Usually correct by design, but confirm it is intentional, and note that it can generally only be changed at open enrollment.
- Worth checking — HSA pacing and Medicare withholding continuity. Both are simple arithmetic and both are quick.
Quick takeaway
The two events that make this audit worth running are the Social Security stop at $184,500 and the Additional Medicare Tax start at $200,000, because both are visible on the stub, both happen mid-year on an attending salary, and only one of them is something payroll systems reliably get right. Everything else on the list is arithmetic you can do in the time it takes to read the stub.
Common questions
How often should I actually do this?
Quarterly is enough, and the quarters are not equivalent. The most valuable run is the one in the second half of the year, after your year-to-date wages have passed $184,500 and $200,000, because that is the only point at which the wage base stop and the surtax start are observable. A run in January tells you almost nothing about either.
Payroll says the Social Security line is correct. How do I show it is not?
Take the year-to-date wages column and multiply by 6.2 percent, capping the wage figure at $184,500. That product is the maximum Social Security tax that can be withheld from you by that employer for the year. If the year-to-date Social Security withheld on your stub exceeds it, the excess is arithmetic, not opinion. Present it that way, in writing, with the stub attached.
My employer pays my disability premium and I would rather have the benefit tax-free. Can I change that?
Sometimes, and generally only at open enrollment. Some group plans permit an election to have the employer-paid premium included in your taxable income, which then makes the benefit non-taxable under the Publication 525 rule. Whether your plan offers it, and on what terms, is a plan-document question — practice varies substantially, so ask benefits administration directly rather than assuming either answer.
I front-loaded my deferrals and already hit $24,500. Is the match gone?
If your plan has a true-up, no — the plan will pay the difference after year end, typically in the first quarter. If it does not, the match for the remaining periods is generally not recoverable, because there is nothing to match. Confirm which regime you are in by reading the summary plan description, and reset your election for next year so the contributions land evenly.
Does the 0.9 percent surtax withheld on my stub mean I owe exactly that much?
Not necessarily. Your employer withholds based on wages from that employer exceeding $200,000, without regard to your filing status. Your actual liability depends on your household's combined wages against your filing-status threshold, which for married filing jointly is $250,000 on a joint basis. Two attendings each under $200,000 individually may owe the surtax with nothing withheld; a single attending over $200,000 may have withholding that roughly matches. Form 8959 reconciles the difference at filing.
What to do next
- Pull your most recent pay stub with year-to-date columns, and put a recurring quarterly reminder on your calendar for this audit, with one of the runs falling after your year-to-date wages pass $200,000.
- Divide base salary by your actual period count and reconcile it against gross on a clean period. Name every dollar of variance.
- Multiply year-to-date wages, capped at $184,500, by 6.2 percent, and confirm the year-to-date Social Security withheld does not exceed it.
- Confirm Medicare has never stopped, and confirm the 0.9 percent line appeared after year-to-date wages crossed $200,000 with that employer.
- Run the IRS Tax Withholding Estimator with your year-to-date figures, and adjust Step 4(c) of your W-4 if the projection is off by an amount you would not want to write a check for.
- Request the summary plan description, search it for a match true-up, and set your per-period deferral to reach $24,500 by the final pay period rather than before it.
- Confirm your HSA election paces to $4,400 or $8,750 net of any employer contribution, and confirm health premiums are pre-tax while disability premiums are post-tax by design.
A pay stub is a monthly assertion by your employer about how much of your money belongs to you, and it is the only financial document you receive twenty-four times a year that almost nobody reads twice. Ten minutes a quarter is a low price for confirming the assertion is true. This is education, not individualized financial advice.