SSI vs SSDI: The Difference, Who May Qualify, and Whether You Can Get Both

Key facts

1How are SSI and SSDI alike, and how are they different?

Social Security runs two disability programs. SSDI pays people who are "insured" through Social Security taxes on their own work, or that of a spouse or parent. SSI "makes cash payments to people who are aged, blind, or have developed a disability (including children) and who have limited income and resources. The federal government funds SSI from general tax revenues." (SSA, Red Book)

What they share: for both, "You must meet Social Security's disability criteria." What differs is who pays for them, who may qualify, and what comes with them. (SSA, Red Book) SSI also covers people 65 or older without a disability; see our Senior Money Checklist for that side. (SSA, Who can get SSI)

2Who may qualify for SSDI?

To be eligible for SSDI, Social Security says you must have worked in jobs covered by Social Security and have a medical condition that meets its "strict definition of disability." (SSA, How Does Someone Become Eligible?)

Work credits come from your yearly earnings, up to four a year. In 2027, one credit takes $1,970 of earnings (official). (SSA, Quarter of Coverage) Generally you need 40 credits, 20 of them earned in the last 10 years ending with the year your disability begins, which Social Security calls the 20/40 rule. Younger workers may be eligible with fewer credits. (SSA, How Does Someone Become Eligible?)

The disability test is strict. You cannot do work at the substantial gainful activity level because of your condition, you cannot do your past work or adjust to other work, and the condition has lasted or is expected to last at least 12 months or to result in death. "No benefits are payable for partial disability or for short-term disability." (SSA, How Does Someone Become Eligible?) For 2027, the official substantial gainful activity level is $1,770 a month, or $2,950 if you are blind. (SSA, Substantial Gainful Activity) The five month wait and the full earnings table are in our guide to SSDI waiting periods and when Medicare starts.

Family members, such as minor children, may also get benefits on the worker's record. (SSA, Red Book)

3Who may qualify for SSI?

Adults and children might be eligible for SSI if they have little or no income, little or no resources, and a disability, blindness, or are age 65 or older. (SSA, Who can get SSI)

The resource limit is $2,000 for one person and $3,000 for a couple (official limits, unchanged for 2027). "If you're a parent applying for a child, these numbers increase by $2,000." (SSA, Who can get SSI) (SSA, 2027 COLA Fact Sheet)

Not everything you own counts. Social Security does not count the home you live in and the land it is on, household goods and personal effects, one vehicle used for transportation, burial spaces, burial funds up to $1,500 each for you and your spouse, and up to $100,000 in an ABLE account (official limits). (SSA, SSI Resources)

To get SSI you must live in one of the 50 states, the District of Columbia, or the Northern Mariana Islands, and be a U.S. citizen or national or meet certain noncitizen rules. (SSA, Red Book)

4How much does each one pay in 2027?

SSDI. "We base your SSDI monthly amount on the worker's lifetime average earnings covered by Social Security." Other unearned income or savings do not change it, but workers' compensation and some public disability benefits can reduce it. (SSA, Red Book) Social Security estimates the average monthly benefit for all disabled workers at $1,701 after the 3.6 percent raise, payable in January 2027 (an SSA estimate; your own estimated amount is on your Social Security Statement). (SSA, 2027 COLA Fact Sheet)

SSI. The 2027 federal maximum is $1,029 a month for one person and $1,544 for a couple (official). Social Security subtracts your countable income from that amount, and some states add a supplement. (SSA, SSI Federal Payment Amounts for 2027) The higher SSI payment starts on December 31, 2026. (SSA, COLA Information for 2027) The payment dates are in our guide to SSI payments in 2027. The full list of 2027 amounts is in our guide to the Social Security COLA for 2027.

5Which one comes with Medicare or Medicaid?

SSDI: "Medicare entitlement begins after you have received SSDI benefits for 24 months." SSI: Medicaid, a federal and state program, with rules that vary by state. (SSA, Red Book) Social Security says people who are eligible for SSI are generally eligible for Medicaid. (SSA Blog, January 16, 2025) Social Security also says: "If you get SSI, you can usually get federal benefits like the Supplemental Nutrition Assistance Program (SNAP) and state benefits like Medicaid," and help from those programs will not affect your SSI payment. (SSA, Programs to get more help while on SSI)

Some people have both. "It is possible to have both Medicaid and Medicare." (SSA Blog, January 16, 2025) For the Medicare timing, see SSDI waiting periods and when Medicare starts. For Medicaid limits by state, see Medicaid income limits explained, and for help paying Medicare costs, see Medicare Savings Programs income limits. For SNAP rules for older adults and people with disabilities, see SNAP for seniors.

6Can you get SSI and SSDI at the same time?

Yes. Social Security says: "We use the term 'concurrent' to describe people who are eligible for disability benefits under both the SSDI and SSI programs." (SSA, Red Book) "Adults and children who meet the SSI income and resource requirements may be eligible for SSI and Social Security disability, retirement, or survivors benefits." (SSA Blog, January 16, 2025)

Here is how it works. Social Security benefits count as unearned income for SSI. The first $20 is not counted (an official SSA rule), and the rest is subtracted from the SSI federal benefit rate. (SSA, SSI Income) An example, using the 2027 federal rate of $1,029, federal SSI only, no other income, and no state supplement: if your SSDI is an estimated $700 a month in 2027, Social Security would count $680, and your federal SSI could be about $349 ($1,029 minus $680), for an estimated total of $1,049. (SSA, SSI Income) (SSA, SSI Federal Payment Amounts for 2027)

The takeaway, which is our reading of those rules: SSI can top up a small SSDI check. If your SSDI alone is more than about $1,049 a month in 2027 (estimated), there is usually no federal SSI left, though a state supplement may differ. Social Security's own blog uses the same federal rate plus $20 test, with its 2025 figure. (SSA Blog, January 16, 2025)

If you apply for SSI, does Social Security also look at SSDI?

SSI requires you to apply for other benefits you may be eligible for, including Social Security disability, because SSI is meant to be a last resort. To get SSI, a person must apply for "any other program benefits or payments for which he or she may be eligible (for example, pensions or Social Security benefits)." (SSA, SSI Eligibility) If Social Security sends you a written notice that you may be eligible for another benefit, such as Social Security disability, you generally have 30 days to file for it to keep your SSI eligibility. (SSA, POMS SI 00510.001) You can also apply for both at the same time, and Social Security decides whether you get one, both, or neither. (USA.gov, SSDI and SSI benefits)

Does an SSI denial affect SSDI?

The two programs test different things. SSI looks at your income and resources. SSDI looks at your work record, and "Other unearned income or resources do not affect your payment amount." Both use the same disability criteria. (SSA, Red Book) Our reading of those rules: a denial because your income or savings are over SSI's limits is about SSI's money test, which SSDI does not have. If a notice says your condition does not meet the disability rules, read the notice for each program. Social Security says each notice "will explain your appeal rights." (SSA, SSI Application Process and Applicants' Rights)

Does the $2,000 resource limit apply if you get both?

Yes, to the SSI part. The official 2027 SSI resource limits are $2,000 for one person and $3,000 for a couple, and SSI counts your SSDI check as income. (SSA, 2027 COLA Fact Sheet) (SSA, SSI Income) SSDI itself has no resource limit. (SSA, Red Book) Social Security checks resources as of the first moment of each month, so SSDI money you still have the next month counts toward the SSI limit. (SSA, POMS SI 01110.600) Unspent SSDI or SSI back pay is not counted as a resource for 9 months after you get it. (SSA, POMS SI 01130.600) If you are owed SSDI back pay for months when you also got SSI, Social Security lowers the back pay by the SSI you would not have gotten if SSDI had been paid on time. It calls this windfall offset. (SSA, SSI Spotlight on Windfall Offset)

For when SSDI payments and Medicare start, see SSDI waiting periods and when Medicare starts. For SSI payment dates and 2027 amounts, see SSI payments in 2027.

7What changes if you work?

• SSDI: a trial work period lets you have earnings and still collect benefits. The official 2027 trial work period amount is $1,270 a month. (SSA, Substantial Gainful Activity) (SSA, 2027 COLA Fact Sheet) The official 2027 substantial gainful activity level is $1,770 a month for people who are not blind. (SSA, Substantial Gainful Activity)
• SSI: "The trial work period does not apply to SSI benefits." (SSA, Substantial Gainful Activity) Instead, Social Security does not count "The first $65 of earnings and one half of earnings over $65 received in a month," so SSI goes down gradually as you earn rather than stopping all at once. (SSA, SSI Income) If you get SSI, "you must also tell us each month if there are changes in the amount of your earnings." (SSA, COLA Information for 2027)

Social Security's Ticket to Work program is "free and voluntary" for people who get disability benefits and want to work. (SSA, COLA Information for 2027) The detailed rules are in Social Security's Red Book. (SSA, Red Book)

8How do you apply for SSI, SSDI, or both?

1. Start from Social Security's Disability page for SSDI or its SSI page, or call 1-800-772-1213 (TTY 1-800-325-0778). (SSA, COLA Information for 2027)
2. If you think you may qualify for both, say so. Social Security uses the same disability rules for both programs. (SSA, Red Book) USA.gov says you can apply for both benefits together, and Social Security will tell you the result for each program. (USA.gov, SSDI and SSI benefits)
3. Apply soon after your condition stops you from working. Social Security may pay SSDI for as many as 12 months before the date you applied, if it finds you had a disability then. (SSA, How Does Someone Become Eligible?)
4. Expect a wait for SSDI. Generally there is a five month waiting period. (SSA, How Does Someone Become Eligible?) See SSDI waiting periods.

Applying is free. Social Security says "our services are free of charge," and for SSI, "There is no charge to apply." Its forms page says "All forms are free." (SSA, COLA Information for 2027) (SSA, SSI Application Process and Applicants' Rights) (SSA, Forms) Nobody needs to pay a third party to apply.

Benefit Bull is free, always. You choose how to apply.

Frequently asked questions