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PayslipIQUSA

Deductions explained

A plain-English directory of every deduction you may see on a US pay stub — what each one does to your taxable wages, and what to verify with payroll.

In plain English

US paycheck deductions fall into five buckets. Mandatory tax (federal, state, local income tax, plus Social Security 6.2% and Medicare 1.45%). Pre-tax (Traditional 401(k), HSA, FSA, most health insurance) — reduces federal taxable wages, sometimes also FICA. Post-tax (Roth 401(k), voluntary insurance) — does not reduce taxable wages. Court-ordered (garnishment, child support) — capped by the federal CCPA. Voluntary (union dues, donations).

Mandatory taxes (every paycheck)

Federal income tax withheld

The IRS amount your employer withholds based on your W-4 and earnings.

Aliases: Fed Tax, FIT, FITW

Social Security tax

6.2% of wages up to the annual Social Security wage base.

Aliases: OASDI, SS Tax

Medicare tax

1.45% of all wages, with an additional 0.9% over $200,000.

Aliases: MED, Medicare

State income tax withheld

Your state's share of payroll income tax. Varies by state.

Local / city income tax withheld

City, county, or municipal income tax. Common in OH, PA, IN, NY, MI, KY, MO.

FICA (combined SS + Medicare)

Social Security plus Medicare. Combined employee rate 7.65% on most wages.

Pre-tax deductions (reduce taxable wages)

Traditional 401(k) contribution

Pre-tax retirement contribution. Reduces federal taxable income (not FICA).

HSA contribution

Pre-tax contribution to a Health Savings Account (HDHP required).

FSA contribution (Health or Dependent Care)

Pre-tax flexible spending account. Use-it-or-lose-it.

Health insurance premium

Most employer health, dental, vision premiums are pre-tax (Section 125).

Post-tax deductions (do not reduce taxable wages)

Roth 401(k) contribution

After-tax retirement contribution. Qualified withdrawals are tax-free.

Court-ordered deductions (CCPA-capped)

Wage garnishment

Court-ordered deduction. Federal CCPA caps disposable earnings exposure.

Child support

Income withholding order. CCPA limits up to 50%/55%/60%/65% based on circumstances.

Voluntary deductions

Union dues

Voluntary post-tax deduction in most states.

Worked example

$2,500 biweekly gross. Pre-tax: $250 to traditional 401(k), $125 to health insurance, $50 to HSA = $425 pre-tax total. Federal taxable wages: $2,075. FICA-taxable wages: $2,325 (401(k) does not reduce FICA, but HSA and health do).

Federal tax (single, est.): ~$210. Social Security: $144.15 (6.2% × 2,325). Medicare: $33.71 (1.45% × 2,325). State (e.g. CO 4.4% flat on $2,075): ~$91. Net pay: ~$1,596.

Worked example uses round numbers for clarity. Your actual figures will differ — use the calculator above for an estimate.

What to check on your pay stub

  • Is each deduction line one you recognise from your benefits or W-4 elections?
  • Does the dollar amount match the percentage or premium you expected?
  • For 401(k): does the contribution match your election?
  • For health/dental/vision: does the premium match your benefits portal?
  • For garnishments: do you have a copy of the underlying order?
  • YTD totals: do they match approximately (per-period × periods elapsed)?
If something looks off — ask payroll

A flag here means a polite question is reasonable — not that an error has been made. Use the Ask Payroll Generator to draft a polite, specific message in 30 seconds.

Official sources

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