Benefits Paycheck Calculator: Your Take-Home Before and After Open Enrollment

Quick answer: what open enrollment does to your paycheck

Most of what you choose at open enrollment comes out of your pay before tax, so your take-home falls by less than the deductions. Health premiums, HSA and FSA money skip federal income tax, Social Security, Medicare and (in most states) state tax. A traditional 401(k) skips income tax only. Roth contributions, supplemental life and other voluntary extras come out after tax and cost you dollar for dollar.

Example: a single employee on $75,000, paid every two weeks, picks family medical, dental and vision ($283.00 a paycheck), a family HSA of $3,000 plus $1,000 from the employer, 6% to a traditional 401(k) and $100 a month for transit, under 2027 federal rules with no state tax. The elections take $617.62 a paycheck, but take-home falls only $484.98, because taxes drop by $3,449 a year.

Why benefit deductions cost less than they look

A pre-tax dollar escapes up to three layers of tax:

• Federal income tax at your bracket (10% to 37%).
• Social Security and Medicare (7.65%), but only for Section 125 deductions and commuter benefits, not 401(k) contributions (IRS). Above the $184,500 Social Security wage base ($192,300 in 2027), only Medicare's 1.45% is left to save (2.35% on wages over $200,000, with Additional Medicare) (IRS Topic 751).
• State income tax, in most states.

A state income tax lowers the cost further: at $75,000 in California, $100 of premiums costs $71.05. In New Jersey, which taxes premiums, it costs $80.35. A Roth contribution always costs the full $100, which is why a Roth 401(k) lowers your paycheck more than a traditional one at the same percentage.

Which deductions are pre-tax, and for which taxes

Sources: IRS Pub. 15-B, Table 2-1 for cafeteria plan benefits, dependent care, transportation and group-term life; Pub. 969 for HSAs; IRS retirement plan FAQ for 401(k) and Roth deferrals. Two less obvious rules:

• An HSA contribution made outside payroll (straight to the HSA provider) is deductible on your tax return, but you've already paid 7.65% Social Security and Medicare on it. Through payroll it skips both, so it's worth more.
• Pre-tax disability premiums make the benefit taxable if you ever claim; premiums paid after tax make the benefit tax-free. Fixed-amount plans paid pre-tax (hospital indemnity, critical illness) can also make their payouts taxable, which is why many employers take them after tax.

Want just the take-home number for your state? The state paycheck calculator has a single pre-tax deductions box; this page splits every election out.

States that tax your benefits: New Jersey, Pennsylvania, California

Most states start from federal wages, so pre-tax benefits save state tax too. A few don't follow the federal rules:

New Jersey treats cafeteria plan salary reductions as taxable pay (TB-39(R)) and excludes 401(k) contributions but not 403(b) or 457 plans (NJ Division of Taxation); NJ also taxes HSA money (Newfront) and commuter benefits, except for some state and local government employees (TB-24(R)). NJ hasn't said so directly for dependent care FSAs, but the same salary-reduction rule points to taxing them. Pennsylvania taxes employee contributions to retirement plans but excludes Section 125 health premiums (PA Revenue), and excludes dependent care assistance since 2023 (PA Revenue), described as up to $5,000; whether PA will follow the new $7,500 isn't settled. We found no PA exclusion for commuter benefits, so the calculator taxes them. California taxes HSA contributions, including for SDI (EDD DE 231EB), and kept its dependent care exclusion at $5,000 (EY). Philadelphia's Wage Tax applies to 401(k), premium and HSA salary reductions (City of Philadelphia). The calculator applies the New Jersey, Pennsylvania and California rules; it doesn't include local taxes. Your W-2 shows the result: box 16 is your state wages.

Section 125 cafeteria plans explained

A Section 125 (cafeteria) plan is what lets your employer take benefits out of your pay before tax. The simplest kind, a premium-only plan, covers your share of health premiums; fuller plans add a health FSA, a dependent care FSA and HSA contributions. Commuter benefits work the same way but under a different section (§ 132(f)), and 401(k) contributions under their own rules.

The catch: your elections are locked for the plan year. You can only change them mid-year after a qualifying event, such as marriage, divorce, a birth or adoption, a spouse's job change, or losing other coverage, or after a significant change in a plan's cost or coverage, and only in a way consistent with the event (Treas. Reg. 1.125-4). Your plan may allow fewer changes. Three exceptions: HSA contributions can be changed going forward at any time (IRS Notice 2004-50, summarized by Newfront); commuter benefits aren't Section 125 benefits and can usually be changed month to month; and 401(k) percentages follow the plan's own rules, usually any pay period.

2027 benefit limits at a glance

The 2027 HSA limits are official (Rev. Proc. 2026-24), as is the $192,300 Social Security wage base (SSA). The 2027 401(k) figures are Milliman's projection (PSCA) and the health FSA and commuter figures Mercer's (Mercer); the IRS usually announces them between late October and mid-November, and we update this page when it does. Every limit, with sources, is on the 2027 401(k), IRA and HSA limits page.

How much is health insurance per paycheck?

In 2025 the average worker paid $1,440 a year for single coverage and $6,850 for family coverage, about 16% and 26% of the total premium; the employer paid the rest. Family coverage at small firms (10 to 199 workers) cost workers more, $8,889 on average (KFF 2025 Employer Health Benefits Survey).

Choosing between plans with different premiums and deductibles? Compare HDHP vs PPO first, counting your expected medical bills; then put the winning plan's premium here.

HSA money: yours and your employer's

• One limit for both. Your contributions and your employer's share the $4,500 self-only / $9,000 family limit for 2027 (plus $1,000 at 55 or older). Subtract the employer's deposit before you set yours.
• Employer HSA money isn't part of your paycheck, and it's tax-free, except that California and New Jersey count it as state wages (and California charges SDI on it).
• No general-purpose health FSA. A regular health FSA (yours or a spouse's) makes you ineligible for an HSA; a limited-purpose FSA for dental and vision is fine (Pub. 969).

Deciding between an HSA and an FSA, or how much to put in? The HSA vs FSA calculator shows what each saves and how much FSA money is at risk.

401(k) and Roth deductions in your benefits mix

At the same percentage, a Roth 401(k) lowers your paycheck more, because it's taken after income tax; the traditional contribution saves income tax now and is taxed when you withdraw it. Both still pay Social Security and Medicare. In the example above, $88.00 of every $100 of traditional contributions comes out of take-home, against the full $100 for Roth. Which is better long-term depends on your tax rate now and in retirement: the Roth vs traditional 401(k) calculator works it out, and the 401(k) paycheck calculator shows what any percentage and match do to your pay.

Catch-up contributions (age 50 and older, and higher at 60 to 63) must go in as Roth (if your plan offers Roth) when last year's Social Security wages from your employer were over $150,000 for 2026 catch-ups (IRS), and a projected $155,000 for 2027. Your employer's match never shows on your paycheck.

Setting money aside for child care too? The dependent care FSA is up to $7,500 a household and comes out before income tax, Social Security and Medicare; whether it beats the child care credit is a separate question for the dependent care FSA calculator.

Commuter benefits: transit and parking

Transit passes, vanpools and work parking can come out of pay before income tax, Social Security and Medicare, up to $340 a month each in 2026 (Pub. 15-B) and a projected $350 in 2027. They're two separate limits, so you can use both. Anything over the limit is taxed like pay. The federal bicycle commuting benefit, suspended since 2018, was repealed for good from 2026 (California still excludes it). Unused money usually rolls over month to month, depending on your plan.

What does commuting cost you in time and money overall? Try the commute cost calculator.

Life insurance imputed income and disability premiums

Employer-paid group-term life insurance is tax-free up to $50,000 of coverage. The cost of coverage above that is imputed income: it's added to your taxable wages and to Social Security and Medicare wages, though you never receive it, and shows in W-2 box 12 with code C. The cost is set by the IRS table, not the real premium (Pub. 15-B, Table 2-2):

Example: at 45 with $150,000 of coverage, $100,000 is over the limit, so imputed income is 100 × $0.15 × 12 = $180 a year. You pay Social Security, Medicare and income tax on it: about $1.36 a paycheck in this example, for a single filer paid every two weeks. Your employer doesn't have to withhold income tax on it, so check your stub. If you pay after tax toward that coverage, your payments reduce the imputed amount.

Disability: if your employer offers pre-tax or after-tax disability premiums, after-tax costs a little more now but makes any benefit you receive tax-free; pre-tax premiums make it taxable.

Why your January paycheck looks different

• New elections start. Premiums usually rise each year, and new HSA, FSA or 401(k) amounts begin.
• Social Security restarts. High earners who stopped paying it once they passed the wage base pay 6.2% again from the first paycheck of the year, on wages up to $192,300 in 2027.
• New tax tables. Brackets and the standard deduction are indexed each year, which usually trims withholding slightly.
• The paycheck date counts. A paycheck dated January 2 for December work is a new-year paycheck for tax purposes.

To see what next year's tax tables do on their own, keep your elections the same and compare plan years here, or see 2027 tax brackets.

After you enroll: check your first pay stub

• Line by line: each election should appear at the amount you chose, and premiums and FSA/HSA money should reduce Social Security and Medicare wages too.
• Imputed income: look for a "GTL" or "imputed" line if your life coverage is over $50,000.
• Withholding: big changes in pre-tax deductions change your tax too. If you were already close to owing, update your W-4.
• Missed open enrollment? You can usually change HSA and 401(k) amounts any time; the rest waits for a qualifying event or next year. The year-end money checklist has the other deadlines.

Common questions

Are health insurance premiums taken out before taxes?

Almost always, when you buy through your employer: premiums under a Section 125 plan skip federal income tax, Social Security, Medicare and most state taxes. New Jersey taxes them for state income tax.

Do pre-tax deductions lower Social Security and Medicare tax?

Section 125 deductions (premiums, HSA through payroll, FSAs) and commuter benefits do. Traditional 401(k), 403(b) and 457(b) contributions don't: they lower income tax only.

Why did my paycheck go down after open enrollment?

Usually higher premiums or a new HSA, FSA or 401(k) amount. In January, Social Security also restarts for high earners. Enter last year's and next year's elections above to see which line changed.

How much does $100 of pre-tax benefits cost me?

About $100 minus your tax rate. For a single person on $75,000 with no state tax, $100 of premiums costs about $80.35 of take-home in 2027.

Does my employer's HSA contribution count toward the limit?

Yes. Employer and employee money share one limit, so subtract the employer's deposit from the limit to find your maximum.

Can I have an HSA and an FSA?

A general-purpose health FSA (yours or your spouse's) makes you ineligible for an HSA. A limited-purpose (dental and vision) or post-deductible FSA is fine, and a dependent care FSA doesn't affect HSA eligibility.

Why is group-term life insurance showing as income on my pay stub?

Employer-paid coverage over $50,000 is taxable imputed income, valued at the IRS table rate. It's added to your wages but not paid to you.

Should disability premiums be pre-tax or after-tax?

After-tax costs a little more now but makes the benefit tax-free if you're ever disabled, when the money matters most. If your employer offers the choice, it's worth considering for long-term disability.

Do pre-tax deductions lower my future Social Security benefit?

Slightly: Section 125 deductions aren't Social Security wages, so they don't count toward your earnings record. 401(k) contributions still do.

Can I change my benefit elections mid-year?

Only after a qualifying event such as marriage, a birth, or a change in a spouse's coverage. HSA contributions are the exception: you can change them any time, going forward.

Should I update my W-4 after open enrollment?

Usually not for small changes: withholding adjusts automatically to lower taxable wages. Check it if you made big changes or have imputed income with no withholding.

Sources

1. Publication 15-B (2026), Employer's Tax Guide to Fringe Benefits — Internal Revenue Service. Accessed October 16, 2026.
2. Publication 969, Health Savings Accounts and Other Tax-Favored Health Plans — Internal Revenue Service. Accessed October 16, 2026.
3. Retirement plan FAQs: are retirement plan contributions subject to withholding for FICA, Medicare or federal income tax? — Internal Revenue Service. Accessed October 16, 2026.
4. Topic no. 751, Social Security and Medicare withholding rates — Internal Revenue Service. Accessed October 16, 2026.
5. 26 U.S. Code § 132, Certain fringe benefits — Legal Information Institute, Cornell Law School. Accessed October 16, 2026.
6. 26 U.S. Code § 3121, Definitions (FICA wages) — Legal Information Institute, Cornell Law School. Accessed October 16, 2026.
7. 26 CFR 1.125-4, Permitted election changes — Legal Information Institute, Cornell Law School. Accessed October 16, 2026.
8. HSA contribution election changes — Newfront. Accessed October 16, 2026. Summary of IRS Notice 2004-50, Q&A-58.
9. 401(k) limit increases to $24,500 for 2026, IRA limit increases to $7,500 — Internal Revenue Service. Accessed October 16, 2026.
10. Revenue Procedure 2026-24 (2027 HSA limits) — Internal Revenue Service. Accessed October 16, 2026.
11. 2027 retirement plan limits: near-final projection (Milliman) — Plan Sponsor Council of America. Accessed October 16, 2026. Projection, not official.
12. Mercer projects 2027 transportation and health FSA limits — Mercer (Marsh). Accessed October 16, 2026. June 11, 2026. Projection, not official.
13. Contribution and benefit base — Social Security Administration. Accessed October 16, 2026.
14. 2025 Employer Health Benefits Survey — KFF. Accessed October 16, 2026. Released October 22, 2025. The 2026 survey is expected in late October 2026.
15. Technical Bulletin TB-39(R), Cafeteria plans — New Jersey Division of Taxation. Accessed October 16, 2026.
16. Technical Bulletin TB-24(R), Employer-provided commuter transportation benefits — New Jersey Division of Taxation. Accessed October 16, 2026.
17. NJ Income Tax – Wages — New Jersey Division of Taxation. Accessed October 16, 2026.
18. California and New Jersey HSA state income tax — Newfront. Accessed October 16, 2026. Benefits consultant summary.
19. PA Personal Income Tax Guide: Gross Compensation — Pennsylvania Department of Revenue. Accessed October 16, 2026.
20. Dependent care assistance programs — Pennsylvania Department of Revenue. Accessed October 16, 2026.
21. Information Sheet: Health Savings Accounts and other benefits (DE 231EB) — California Employment Development Department. Accessed October 16, 2026.
22. California law largely does not conform to OBBBA provisions affecting compensation and benefits — EY Tax News. Accessed October 16, 2026. March 18, 2026.
23. What types of income are not subject to the Wage Tax? — City of Philadelphia. Accessed October 16, 2026. June 15, 2020; archived page.

Last checked October 16, 2026.