OASDI tax began in 1935 as part of the Social Security Act

OASDI stands for Old-Age, Survivors, and Disability Insurance. The tax that funds it started on January 1, 1937, when the first payroll deductions appeared on American paychecks. Congress passed the Social Security Act in August 1935, but the tax itself did not begin until nearly two years later.

The original rate was 1 percent of wages, split equally between employer and employee. That means workers paid 0.5 percent and employers paid 0.5 percent. The wage base — the maximum amount of income subject to the tax — was $3,000 per year. In equivalent purchasing power, that is roughly $65,000, though the actual wage base now changes every year based on national wage growth.

The program was created to provide income to workers who reached age 65, as well as to their survivors if they died. Disability coverage was added later, in 1956, which is why the program is called OASDI rather than just Social Security.

Key Takeaways

  • OASDI tax started on January 1, 1937, with an initial rate of 1 percent split between worker and employer.
  • The original wage base was $3,000 per year, and Congress has raised both the rate and the wage base many times since then.
  • Disability insurance was added to the program in 1956, expanding it beyond retirement and survivor benefits.
  • The current tax rate is 12.4 percent total (6.2 percent from workers, 6.2 percent from employers), and the 2024 wage base is $168,600.

How the tax rate and wage base have changed since 1937

Congress has raised the OASDI tax rate many times. By 1950, it had doubled to 3 percent. By 1960, it was 6 percent. The rate continued to climb through the 1970s and 1980s as the program expanded and demographic shifts meant fewer workers per retiree. The current rate of 12.4 percent (6.2 percent from workers, 6.2 percent from employers) has been in place since 1990.

The wage base has also grown substantially. In 1951, it was raised to $3,600. By 1972, it had reached $9,000. The wage base is adjusted every January based on the previous year's average wage growth. For 2024, the wage base is $168,600, meaning that wages above that amount are not subject to OASDI tax. Self-employed workers pay both the employer and employee portions, for a total of 12.4 percent on net self-employment income up to the wage base.

Why the tax was created and what it funds

The Great Depression left millions of elderly Americans without income or savings. President Franklin D. Roosevelt and Congress created Social Security to provide a safety net for workers who could no longer earn wages. The OASDI tax was the funding mechanism — a dedicated payroll tax that would build a reserve and pay benefits to those who may have access to.

OASDI tax funds three separate programs. Old-Age Insurance pays monthly benefits to workers age 62 and older (though benefits are reduced if you claim before your full retirement age). Survivors Insurance pays benefits to the spouse, children, and parents of a worker who dies. Disability Insurance pays benefits to workers under full retirement age who have a severe medical condition expected to last at least 12 months or result in death.

The tax is collected by the Internal Revenue Service and deposited into two trust funds: the Old-Age and Survivors Insurance Trust Fund and the Disability Insurance Trust Fund. These funds pay out benefits each month to roughly 67 million beneficiaries.

How OASDI tax appears on your paycheck

If you are a wage earner, you will see OASDI tax listed separately on your pay stub, usually labeled as "Social Security" or "OASDI." It is deducted from your gross pay before federal income tax. Your employer withholds 6.2 percent of your wages up to the annual wage base and sends that amount, plus an equal 6.2 percent employer contribution, to the IRS.

If you are self-employed, you pay the full 12.4 percent on your net self-employment income, though you can deduct half of it as a business expense when you file your tax return. You report OASDI tax on Schedule SE (Self-Employment Tax) when you file your annual tax return.

Once you reach the wage base for the year, no more OASDI tax is withheld from your paycheck for the rest of that calendar year. This means high-income earners stop paying into the system partway through the year, while lower-income workers pay the tax on all their wages.

The difference between OASDI tax and Medicare tax

OASDI tax and Medicare tax are often confused because they both appear on your paycheck and are both Social Security-related payroll taxes. However, they fund different programs and have different rates and wage bases.

OASDI tax is 12.4 percent total (6.2 percent worker, 6.2 percent employer) and applies only to wages up to the annual wage base. Medicare tax is 2.9 percent total (1.45 percent worker, 1.45 percent employer) and applies to all wages with no upper limit. Additionally, high-income earners pay an extra 0.9 percent Medicare tax on wages above $200,000 (single filers) or $250,000 (married filing jointly).

OASDI funds retirement, survivor, and disability benefits. Medicare funds hospital insurance (Part A), medical insurance (Part B), and prescription drug coverage (Part D). The two programs are separate, though they are both administered by the Social Security Administration.

What happens to the money you pay in OASDI tax

OASDI tax is not held in a personal account with your name on it. Instead, it goes into a general trust fund that pays current beneficiaries. This is called a "pay-as-you-go" system. The taxes paid by workers now fund the benefits paid to current retirees, survivors, and disabled workers.

When you retire, your benefits are funded by the OASDI taxes paid by workers at that time. Your benefit amount is based on your earnings history — specifically, your 35 highest-earning years — and the age at which you claim benefits. The Social Security Administration maintains a record of your earnings and uses that record to calculate your benefit when you become may be able to access.

You can view your earnings record and get an estimate of your future benefits by creating an account on the Social Security Administration website at ssa.gov. The site allows you to see what the agency has on file for you and to project your benefits at different claiming ages.

Frequently Asked Questions

Is OASDI tax the same as Social Security tax?

Yes. OASDI tax and Social Security tax are the same thing. "Social Security tax" is the common name, and "OASDI tax" is the official name because it funds Old-Age, Survivors, and Disability Insurance. You will see both terms used on paychecks and tax documents.

Do I pay OASDI tax on all my income?

No. OASDI tax applies only to wages up to the annual wage base, which changes every year. For 2024, the wage base is $168,600. Income above that amount is not subject to OASDI tax. Investment income, rental income, and other non-wage income are also not subject to OASDI tax.

What if I worked before 1937?

Workers who were already retired or had stopped working before 1937 did not pay OASDI tax. The program was designed to cover workers going forward. Some very early retirees received small benefits based on contributions they made after 1937, but the program was not retroactive.

Can I get back the OASDI tax I paid if I don't claim benefits?

No. OASDI tax is a mandatory payroll tax, not a voluntary contribution to a personal account. If you die before claiming benefits, your survivors may be may have access to to survivor benefits based on your earnings record. If you have no may be able to access survivors, the money you paid does not go back to your estate.

Why does the OASDI wage base change every year?

The wage base is adjusted annually to reflect growth in average wages across the economy. This keeps the program's funding in line with wage growth and ensures that the tax captures a consistent share of the nation's total wages. The adjustment is made every January based on the previous year's average wage data.