What's the difference between SSDI and SSI?

Andy Markowitz,

Updated January 02, 2025

AARP

Comments

En español

Published October 26, 2020

/ Updated January 02, 2025

Social Security Disability Insurance (SSDI) and Supplemental Security Income (SSI) both pay benefits to people that the Social Security Administration deems to have a disability.

With their similar initials and overlapping missions, the two programs can be easy to confuse — but they differ in fundamental ways. Here are some of the key distinctions.

Who qualifies

SSDI is available to people with physical and mental impairments severe enough to prevent them from engaging in their normal occupations or any other substantial work. The disability must be expected to last for at least 12 months or to end in death.
SSI is a safety net program that pays benefits to people with very limited income and assets, who are 65 or older, blind or are deemed to have a disability, usually based on the same definition used for SSDI.

How to qualify

SSDI is an earned benefit. As with Social Security retirement benefits, you qualify by working and paying Social Security taxes. How long you must have worked to be eligible varies based on your age when your disability began.

As it does for the spouses and children of retirees, Social Security can pay additional benefits to the spouses and children of disabled workers. Adults who have had a disability since childhood may qualify for SSDI on a parent's record even if they've never worked.

SSI is not tied to a recipient's work history. You can receive SSI if you've never worked or paid Social Security taxes. But your income and other financial resources, such as bank accounts and property, must not exceed strict caps.

In 2025, the maximum federal SSI payment is $967 a month for an individual and $1,450 a month for a couple receiving SSI jointly. Income up to those levels can result in your benefit being reduced; income above them can render you ineligible for the program.

The resource limit is $2,000 for an individual and $3,000 for a couple.

Not all income and assets count against the caps. For example, Social Security exempts the value of your home and about half of earnings from work, among other things.

Financing and administration

SSDI dates to 1956, when Social Security's rules were amended to permit benefit payments to disabled workers.

Both workers and their employers primarily bear the cost of the program through payroll taxes. Benefits are paid out of Social Security's Disability Insurance Trust Fund.

Payment amounts are based on your earnings history. In November 2024, the average monthly SSDI benefit was $1,542.

SSI is managed by the Social Security Administration (SSA), but Social Security taxes do not pay for it. Rather, SSI is paid out of general revenues that the Treasury Department collects to run the U.S. government.

Social Security was put in charge of SSI when the program was established in 1972 to replace a patchwork of state programs that provided federally financed benefits for people who are older, blind or have a disability and are in financial need. Most states offer supplemental benefits to SSI recipients on top of the federal payment.

How they're similar

The SSA generally uses the same medical criteria and the same process to determine if a disability entitles an adult to SSDI or SSI. Collecting both benefits is permitted.

The condition must be expected to last at least a year or result in death and must prevent you from doing most work.

Social Security requires considerable medical evidence to back up a disability claim for either benefit. Although you can apply online for SSDI, and in some cases for SSI, the process will include an in-person or phone interview with a Social Security representative.

In 2024, it took about seven-and-a-half months on average to get a decision on an initial application for disability benefits, according to SSA data. Military veterans and people with particular severe medical issues may qualify for expedited processing.

Keep in mind

A majority of applications for disability benefits are initially denied. If your application is rejected, you have the right to appeal, but getting a hearing can take a year or more. The SSA has a considerable backlog of cases.

%{postComment}%

Andy Markowitz is an AARP senior writer and editor covering Social Security and retirement. He is a former editor of the Prague Post and Baltimore City Paper.

Unlock Access to AARP Members Edition

Join AARP to Continue

Already a Member? Login

More Social Security FAQs