What Is OASDI? — Social Security Tax on Your Paycheck, FICA, Rates & How to Calculate
12 min readUpdated: February 5, 2026
You see it on every paycheck: a line labeled OASDI, SS, Soc Sec, or FICA-SS — and it takes 6.2% of your gross pay. What is OASDI on your paycheck? It's the Social Security tax that funds retirement, survivor, and disability benefits. This guide explains the OASDI deduction, what is OASDI FICA, what is FICA OASDI, and what is FICA - OASDI — plus how to calculate Social Security withholding, the wage base cap, and why Social Security wages differ from your W-2 wages.
See OASDI on Your Own Pay Stub
Generate a professional pay stub showing your OASDI deduction at the correct 6.2% rate.
OASDI stands for Old-Age, Survivors, and Disability Insurance — the federal program most people know as Social Security. The OASDI tax is a mandatory payroll tax that funds three types of benefits. The oasdi payroll deduction, paycheck oasdi line, and payroll oasdi withholding all refer to the same 6.2% tax. The oasdi tax deduction funds:
Component
What It Funds
Who Benefits
Old-Age (OA)
Retirement benefits
Workers age 62+ with 40+ quarters of coverage
Survivors (S)
Death benefits
Spouses, children, and dependents of deceased workers
Disability Insurance (DI)
Disability income
Workers unable to work due to qualifying disability
OASDI vs FICA — What's the Difference?
What is OASDI FICA? What is FICA OASDI? What is FICA - OASDI? These all refer to the same relationship: FICA is the umbrella law, and OASDI is one of two taxes under it. The Federal Insurance Contributions Act (FICA) mandates two payroll taxes: OASDI (Social Security) and Medicare. Together they make up your total FICA tax.
The OASDI on paycheck line appears in the taxes section of your pay stub. Here's what it looks like across different payroll providers, and what the FICA on paycheck stub labels mean:
Payroll Provider
OASDI Label
Medicare Label
Combined FICA?
ADP
OASDI or Soc Sec
Medicare
Separate lines
QuickBooks
Social Security
Medicare
Separate lines
Gusto
Social Security
Medicare
Separate lines
Generic / Custom
FICA-SS, FICA SS, SS
FICA-MED, MED
Sometimes combined as "FICA"
Quick check: Your OASDI deduction should equal roughly 6.2% of your gross pay. On a $3,000 gross paycheck: $3,000 × 0.062 = $186. If your OASDI is significantly different, check whether pre-tax deductions are reducing your OASDI taxable wages. For provider-specific guidance, see ADP pay stubs or QuickBooks pay stubs.
OASDI Rate & Wage Base Cap (2025)
Year
OASDI Rate
Wage Base Cap
Max Employee OASDI
2025
6.2%
$176,100
$10,918.20
2024
6.2%
$168,600
$10,453.20
2023
6.2%
$160,200
$9,932.40
The OASDI rate has been 6.2% since 1990. The wage base cap increases annually based on the national average wage index. Once your year-to-date earnings exceed the cap, OASDI withholding stops for the rest of the year — you'll see $0 on that line. The payroll social security limits reset each January 1.
How to Calculate Social Security Withholding
How to calculate social security tax withholding, how is social security withholding calculated, how to calculate social security withholding, and how to figure social security withholding — all the same process:
1
Find Your Gross Pay
Look at the earnings section total — this is your starting point.
Why is social security wages higher than wages on w2? This is one of the most common pay stub questions. The difference between wages and social security wages comes down to which deductions reduce each number. Here's how to calculate social security wages on w2, how to calculate social security wages w2, how do you calculate social security wages on w2, how to figure social security wages on w2, and how are social security wages calculated on w2. Is social security wages gross income? Not exactly — it's gross wages minus only Section 125 deductions, which makes it close to gross but not identical.
W-2 Box
What It Shows
What Reduces It
Box 1 — Wages
Taxable wages for federal income tax
401(k), health insurance, HSA, FSA, transit — all pre-tax deductions
Box 3 — SS Wages
Social Security taxable wages
Only Section 125 (cafeteria) deductions like dependent care FSA
Box 4 — SS Tax
Total OASDI withheld
Should equal Box 3 × 6.2%
Example: If your gross wages are $80,000 and you contribute $6,000 to a traditional 401(k) and $3,000 to health insurance: Box 1 = $80,000 − $6,000 − $3,000 = $71,000. But Box 3 = $80,000 (401k and health insurance don't reduce SS wages). That's why social security wages are higher than wages on your W-2.
The max social security tax withholding is the most OASDI you can pay in a single year. It's calculated as 6.2% × the wage base cap:
Year
Wage Base
Max Employee OASDI
When Withholding Stops
2025
$176,100
$10,918.20
When YTD gross reaches $176,100
If you earn above the cap — say $200,000 — you'll stop paying OASDI partway through the year. On a biweekly schedule, this typically happens around pay period 23 (late November). You'll notice your paycheck suddenly gets larger because the 6.2% deduction disappears.
OASDI Taxable Wages
OASDI taxable wages are the earnings subject to the 6.2% Social Security tax. The OASDI tax deduction applies to nearly all forms of compensation:
Different payroll systems use different labels for the same taxes. Here's what FICA EE on paycheck means, what is FICA SS on my paycheck, what FICA deduction on paystub refers to, and what med FICA on paycheck is:
Stub Label
What It Means
Rate
FICA EE
FICA Employee — your combined SS + Medicare (FICA ee on paycheck)
7.65%
FICA SS or FICA-SS
Social Security portion only (what is FICA SS on my paycheck)
6.2%
FICA MED or Med FICA
Medicare portion only (med FICA on paycheck)
1.45%
FICA ER
FICA Employer — your employer's matching portion (not on your stub)
7.65% (employer pays)
Employer Match & Self-Employment Tax
Your employer pays an additional 6.2% OASDI on your behalf — you only see your 6.2% on your pay stub. Self-employed workers pay both halves:
Worker Type
SS Rate
Medicare Rate
Total FICA
Employee (W-2)
6.2% (employee) + 6.2% (employer)
1.45% + 1.45%
15.3% total (you pay 7.65%)
Self-Employed (1099)
12.4% (both halves)
2.9% (both halves)
15.3% total (you pay all)
Self-employed workers can deduct 50% of self-employment tax on their income tax return (the "employer half"). For self-employment pay stubs, see self-employed pay stubs. For more on Social Security limits from the Social Security Administration.
Verify Your OASDI Deduction
Generate a pay stub showing your OASDI deduction at the correct 6.2% rate — verify your Social Security tax is accurate and matches your expected withholding.
OASDI stands for Old-Age, Survivors, and Disability Insurance — it's the official name for Social Security tax. On your paycheck, the OASDI deduction is 6.2% of your gross pay (up to the annual wage base of $176,100 in 2025). This funds retirement benefits, survivor benefits, and disability payments through the Social Security Administration.
What is OASDI FICA?
FICA (Federal Insurance Contributions Act) is the law that requires both Social Security (OASDI) and Medicare taxes. OASDI FICA refers specifically to the Social Security portion of FICA taxes. Together, FICA = OASDI (6.2%) + Medicare (1.45%) = 7.65% of your gross pay. On your stub, you may see 'FICA-OASDI' or 'FICA/OASDI' as a single line item.
What is FICA SS on my paycheck?
FICA SS on your paycheck is the same as OASDI — it's your Social Security tax at 6.2% of gross wages. Different payroll systems use different labels: OASDI, FICA SS, Soc Sec, SS Tax, or Social Security. They all mean the same 6.2% deduction.
How is Social Security withholding calculated?
Social Security withholding is calculated as 6.2% of your gross wages each pay period, up to the annual wage base ($176,100 in 2025). Once your year-to-date earnings reach the cap, withholding stops for the rest of the year. Formula: Gross Pay × 0.062 = OASDI withholding per period.
Why is Social Security wages higher than wages on W-2?
Social Security wages (W-2 Box 3) can be higher than regular wages (Box 1) because pre-tax deductions like 401(k) and health insurance reduce Box 1 but do NOT reduce Box 3. Social Security wages include nearly all compensation before pre-tax retirement deductions. The difference between wages and Social Security wages is these pre-tax benefit deductions.
What is the max Social Security tax withholding?
The max Social Security tax withholding for 2025 is $10,918.20 (which is 6.2% × $176,100 wage base). Once your year-to-date earnings hit $176,100, your employer stops withholding OASDI for the rest of the year. If you change jobs mid-year and both employers withhold OASDI, you may exceed the cap — claim the excess as a credit on your tax return.
What is FICA EE on my paycheck?
FICA EE means 'FICA Employee' — the employee's share of FICA taxes. It typically refers to the combined Social Security (6.2%) and Medicare (1.45%) = 7.65%. 'EE' stands for 'employee' to distinguish your portion from the employer's matching portion (FICA ER). Some stubs split this into FICA-SS EE and FICA-MED EE.
How do you calculate Social Security wages on W-2?
To calculate Social Security wages on W-2 (Box 3): start with gross wages, then subtract only Section 125 cafeteria plan deductions (like dependent care FSA). Do NOT subtract 401(k), health insurance premiums, or HSA contributions — these reduce Box 1 but not Box 3. Social Security wages are capped at $176,100.
Is the OASDI deduction the same as Social Security?
Yes — OASDI and Social Security are the same thing. OASDI (Old-Age, Survivors, and Disability Insurance) is the technical/legal name; Social Security is the common name. On your pay stub, you'll see one or the other: OASDI, SS, Soc Sec, FICA-SS, or Social Security. All refer to the same 6.2% tax.
What are OASDI taxable wages?
OASDI taxable wages are the portion of your earnings subject to the 6.2% Social Security tax. Nearly all compensation is OASDI taxable — regular pay, overtime, bonuses, commissions. The main limit is the annual wage base cap ($176,100 in 2025). Earnings above the cap are not subject to OASDI tax, though they are still subject to Medicare tax.