The core difference: work history versus need

SSDI (Social Security Disability Insurance) is based on your own work record and the taxes you paid into Social Security. SSI (Supplemental Security Income) is based on financial need, not work history. You cannot receive both at the same time, though you can switch from one to the other under certain conditions.

If you worked and paid Social Security taxes before becoming disabled, you likely have a path to SSDI. If you have little or no work history, or if your work record does not may have access to you for SSDI, SSI may be your route instead. The program you enter determines your monthly payment amount, what counts as income, and how much you can earn before your benefits reduce.

Both programs use the same medical definition of disability — you must have a condition expected to last at least 12 months or result in death, and it must prevent you from doing substantial work. But the money comes from different sources, and the rules around what you own and earn are very different.

Key Takeaways

  • SSDI is for people with a work history who paid Social Security taxes; SSI is for people with little or no work history and limited income and resources.
  • SSDI payments are based on your past earnings; SSI payments are the same for everyone in your state and are much lower.
  • SSI has strict limits on how much money and property you can own; SSDI has no resource limits once you are approved.
  • If you receive SSI and later become SSDI-insured through work or a family member's record, you may be able to switch programs and receive a higher payment.
  • Both programs count earned income the same way, but SSI counts unearned income (like gifts or help from family) while SSDI generally does not.

How your work history determines which program you enter

Social Security tracks the work credits you earn by paying taxes on your wages. You need 40 credits total to be SSDI-insured, and you must have earned at least 20 of those credits in the 10 years before you became disabled. If you meet those requirements, you enter SSDI.

If you do not have enough work credits, you do not may have access to for SSDI on your own record. At that point, you can look at SSI instead. SSI has no work requirement — you can have zero work history and still be considered. But SSI requires that your total income and resources fall below a threshold set by Social Security. In 2024, that threshold is $943 per month in countable income for an individual, though this amount changes yearly.

Younger workers sometimes may have access to for SSDI on a parent's or spouse's work record even if they have not worked enough themselves. This is called "auxiliary" SSDI. If you are under 19 (or under 23 if in school full-time) and your parent is receiving SSDI or retirement benefits, you may be insured on their record. This is still SSDI, not SSI, and the payment rules are different.

Monthly payment amounts and how they are calculated

SSDI payments vary widely because they are based on your own earnings record. Social Security calculates your Primary Insurance Amount (PIA) using your 35 highest-earning years. If you earned more during your working life, your SSDI payment is higher. The average SSDI payment in 2024 is around $1,550 per month, but individual payments range from under $700 to over $3,800 depending on your work history.

SSI payments are uniform within each state because they are not based on work history. The federal base rate for 2024 is $943 per month for an individual living independently. Many states add a supplement on top of the federal amount, so your SSI payment depends partly on where you live. SSI payments are significantly lower than the average SSDI payment, and they do not increase based on your past earnings.

Both programs receive annual cost-of-living adjustments (COLA) each January. The adjustment is the same percentage for both SSDI and SSI, but because SSDI payments start higher, the dollar increase is larger. For example, if COLA is 3 percent, an SSDI recipient earning $1,500 gets a $45 raise, while an SSI recipient earning $943 gets a $28 raise.

Resource and income limits: the biggest practical difference

SSI has strict limits on what you can own. You can have no more than $2,000 in countable resources as an individual (or $3,000 if you are married and both receive SSI). Countable resources include cash, bank accounts, stocks, and property other than your home and one vehicle. If you go over the limit, you lose SSI entirely until your resources drop back down.

SSDI has no resource limit. Once you are approved for SSDI, you can own a house, multiple vehicles, savings accounts, and investments without affecting your benefits. This is one of the largest practical differences between the two programs.

Both programs count earned income (money from work) the same way. In 2024, you can earn up to $1,550 per month without losing benefits, and benefits reduce by $1 for every $2 you earn above that. But SSI also counts unearned income — gifts from family, help with rent, food information, or money from other sources. SSDI generally does not count unearned income, which means you can receive help from family or other programs without it affecting your SSDI payment.

What happens if you work while receiving benefits

Both SSDI and SSI allow you to work and still receive benefits, up to a point. The first $65 per month you earn is not counted, and then half of everything above that is deducted from your benefits. This is called the "substantial gainful activity" (SGA) test, and the SGA threshold in 2024 is $1,550 per month.

If you earn more than the SGA amount for nine months in a row, you enter a "trial work period" where you can test your ability to work without losing benefits. After the trial work period ends, if you are still earning above SGA, your benefits stop. But you have a "grace period" where you can return to benefits quickly if you stop working or drop below SGA again.

SSI has an additional complication: if you receive help with food or shelter from someone else, that counts as income and reduces your SSI payment. SSDI does not have this rule. This means an SSI recipient who lives with family and receives help with rent may lose more in benefits than an SSDI recipient in the same situation.

How to move from SSI to SSDI or vice versa

If you are receiving SSI and you later become SSDI-insured — either through your own work or through a family member's record — you can request a change. Social Security will switch you to SSDI if your SSDI payment is higher than your SSI payment. This usually happens when you return to work and earn enough credits, or when a parent or spouse begins receiving retirement or disability benefits.

The switch is not automatic. You must contact Social Security and ask them to review your record. Bring documentation of any new work you have done or any family member's benefit claim. Social Security will recalculate your SSDI entitlement and tell you whether the switch will increase your payment.

Moving from SSDI to SSI is much rarer and usually happens only if your SSDI benefit ends — for example, if you reach full retirement age and your disability benefit converts to a retirement benefit. In that case, if your retirement benefit is very low and you have limited resources, you might be able to receive SSI as a supplement.

Medicare, Medicaid, and other benefits that come with each program

SSDI recipients receive Medicare after 24 months of receiving benefits. Medicare is the federal health insurance program for people over 65 and some younger people with disabilities. You pay premiums for Medicare Part B (medical insurance) and Part D (prescription drug coverage), though the premiums are deducted from your SSDI payment.

SSI recipients receive Medicaid, which is the joint federal-state health insurance program for low-income people. Medicaid is free — there are no premiums. In most states, you are automatically Medicaid-may be able to access once you are approved for SSI. Medicaid covers more services than Medicare, including dental, vision, and long-term care, though coverage varies by state.

If you switch from SSI to SSDI, you lose Medicaid when ready and must enroll in Medicare. There is a gap period where you have neither program, so plan ahead. If you switch from SSDI to SSI, you gain Medicaid coverage. Some people try to time their work or earnings to stay on SSI specifically because Medicaid is more comprehensive than Medicare.

Frequently Asked Questions

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

No. Social Security will not pay both programs simultaneously. If you are approved for both, Social Security pays whichever gives you the higher benefit and stops the other. If your circumstances change and you become may be able to access for a higher benefit under the other program, you can request a switch.

If I am on SSI and I inherit money, what happens to my benefits?

If you inherit more than $2,000, you will lose SSI when ready because your resources exceed the limit. If you inherit less than $2,000, your SSI continues. If you are on SSDI, an inheritance does not affect your benefits at all because SSDI has no resource limit.

What if I worked part-time and do not have 40 work credits?

You do not may have access to for SSDI on your own record. You can look at SSI if your income and resources are low enough, or you can check whether you are insured on a family member's record (parent, spouse, or ex-spouse). Social Security can tell you in one call whether you have any path to benefits.

Do I have to report gifts from family if I am on SSI?

Gifts count as unearned income on SSI and reduce your payment dollar-for-dollar after the first $20 per month. If someone gives you $500, your SSI payment drops by $480 that month. On SSDI, gifts do not count as income and do not affect your payment.

How do I find out which program I should pursue?

Contact Social Security at 1-800-772-1213 or visit your local Social Security office. Bring your Social Security card, birth certificate, and any medical records related to your condition. A representative can review your work history and tell you whether you may have access to for SSDI, SSI, or both.