The core difference: who paid into Social Security, and how much you have now

SSDI (Social Security Disability Insurance) is for people who worked and paid Social Security taxes. The government uses your work history to decide if you may have access to and how much you receive each month. SSI (Supplemental Security Income) is for people with very low income and few assets, regardless of work history — it's a needs-based program, not an insurance program.

The simplest way to think about it: SSDI is what you earned through work. SSI is what the government provides because you need it. You cannot receive both programs at the same time, though some people transition from one to the other as their circumstances change.

Both programs require you to have a medical condition that prevents substantial work. Both are administered by the Social Security Administration. But the rules about who qualifies, how much you get, and what happens if you earn money are completely different.

Key Takeaways

  • SSDI is based on your own work history or a parent's work history; SSI is based on your current income and assets, not work history.
  • SSDI has no income or asset limits; SSI limits your countable resources to $2,000 (or $3,000 if you are married) and counts most income against your payment.
  • SSDI payments are usually higher than SSI, because they are based on what you earned; SSI payments are the same for everyone in your state, typically $900 to $950 per month federally, plus any state supplement.
  • If you work and earn money, SSDI allows you to keep more of your payment; SSI reduces your payment by $1 for every $2 you earn above $65 per month.
  • You can receive both programs only in rare circumstances, and only temporarily — most people must choose one or transition between them.

How work history determines which program you can receive

To receive SSDI, you must have worked long enough and recently enough to have "insured status." The Social Security Administration looks at your earnings record to see if you paid into the system. Generally, you need 40 work credits, and at least 20 of those credits must have been earned in the 10 years before you became disabled. (The rules are different if you became disabled before age 22; in that case, a parent's work record may may have access to you.)

SSI has no work requirement at all. You do not need to have worked, and your parents' work history does not matter. SSI only cares about your current income and assets. If you have never worked, or worked only briefly, SSI is the only program available to you.

This is why many young adults who became disabled before they could work, or people who worked very little, end up on SSI. People who worked for years and then became disabled usually may have access to for SSDI instead.

Income and asset limits: why SSI is much more restrictive

SSDI has no income or asset limits. You can own a house, a car, have a savings account with $100,000 in it, and still receive your full SSDI payment. The only income that matters is earned income — money you make from working. Even then, you can earn up to $1,550 per month (as of 2024) before your SSDI payment is reduced.

SSI is the opposite. Your countable resources cannot exceed $2,000 if you are single, or $3,000 if you are married. A house you live in does not count, and one car does not count, but a second car, a savings account, or investments all count toward the limit. If you go over the limit, you lose SSI entirely until your resources drop back down.

Income counts against SSI much more aggressively. The first $65 per month you earn does not count. After that, SSI reduces your payment by $1 for every $2 you earn. If you earn $200 per month, your SSI payment drops by $67.50. This is why many SSI recipients cannot work, even part-time — the reduction in benefits makes it not worth their time.

Monthly payment amounts and where they come from

SSDI payments vary widely because they are based on your earnings record. Someone who worked at high wages for 30 years will receive much more than someone who worked part-time for 10 years. The average SSDI payment in 2024 is around $1,550 per month, but payments range from under $700 to over $3,800 depending on your work history.

SSI payments are the same for everyone in the same situation within a state. The federal base payment for 2024 is $943 per month for an individual. Many states add a supplement on top of that — California adds $70, for example, while other states add nothing. Your SSI payment does not change based on your work history; it changes only if your income or assets change, or if you move to a different state.

Because SSDI is based on what you earned, your payment is usually higher than SSI. This is one reason people prefer SSDI when they may have access to for both programs.

What happens if you work while receiving benefits

SSDI has a trial work period that lasts nine months. During this time, you can earn any amount and keep your full SSDI payment. After the trial work period ends, you enter an extended may be able to access period where you can earn up to $1,550 per month (the "substantial gainful activity" limit) and keep your full payment. If you earn more than that, your payment is reduced by $1 for every $2 over the limit.

SSI has no trial work period. Any money you earn counts immediately. The first $65 per month is excluded, but after that your payment drops by 50 cents for every dollar you earn. This makes it very hard to work while on SSI without losing most of your benefit.

Both programs have work incentives available — programs like PLAN to Achieve Self-Support (PASS) that let you set aside income and resources for work-related goals without losing benefits. But the basic rules are much more generous for SSDI than for SSI.

Medical requirements: the one thing both programs share

Both SSDI and SSI require the same medical standard: you must have a condition that prevents you from doing substantial work, and the condition must last at least 12 months or result in death. The Social Security Administration uses the same list of conditions (called the Blue Book) to evaluate both programs.

The difference is not in the medical standard — it is in what happens after you are approved. With SSDI, once you are on the program, your medical condition is reviewed periodically, but you keep your benefits as long as your condition has not improved enough to allow work. With SSI, your medical condition is reviewed the same way, but you also lose benefits if your income or assets go up, even if your condition has not changed.

Transitioning between SSI and SSDI

Some people start on SSI because they have never worked, then later become may be able to access for SSDI when they have worked long enough. When this happens, you do not automatically switch programs — you must report the work to Social Security and ask to be evaluated for SSDI. Once you are approved for SSDI, your SSI ends.

The reverse can also happen: someone on SSDI might lose SSDI may be able to access if their condition improves enough to allow work, but they might then become may be able to access for SSI if their income and assets are low enough. This is less common, but it can occur.

A few people receive both programs temporarily during the transition, but this is rare and usually lasts only a month or two while paperwork is processed. You cannot intentionally stay on both programs.

Frequently Asked Questions

Can I receive both SSI and SSDI at the same time?

In rare cases, yes, but only temporarily and only for a short period during a transition between programs. Most people must choose one or the other. If you are approved for SSDI while receiving SSI, your SSI ends and you receive only SSDI.

If I have never worked, can I get SSDI?

Not on your own work record. However, if you became disabled before age 22, you may be able to receive SSDI based on a parent's work record — this is called "disabled adult child" benefits. Otherwise, SSI is your only option if you have never worked.

Which program pays more money?

SSDI usually pays more because it is based on your earnings history. SSI pays the same federal base amount to everyone ($943 per month in 2024, plus any state supplement). However, some people with very high earnings histories receive SSDI payments of $3,000 or more, while others with lower work histories receive less than $1,000.

What if I own a house — does that affect my SSI or SSDI?

A house you live in does not count as a resource for SSI purposes, so it does not affect your SSI payment. SSDI has no resource limits at all, so owning a house never affects SSDI. Investment properties or second homes do count toward SSI resource limits.

Can I work part-time and keep my benefits?

With SSDI, yes — you can earn up to $1,550 per month and keep your full payment (after the trial work period ends). With SSI, working part-time usually reduces your payment significantly because earnings count against your benefit starting at $65 per month. Many SSI recipients find it is not worth working because the benefit reduction is too steep.