In certain circumstances, you can collect SSI and SSDI at the same time (called "concurrent benefits"). This happens when a disability applicant is approved for Social Security Disability (abbreviated as SSD or SSDI) but receives only a low monthly payment. Someone usually gets a low SSDI payment if they made low wages or they did not work much in recent years.
To qualify for an SSI payment in addition to an SSDI payment, your unearned income (meaning SSDI) must be less than $750 per month. The SSI income limits are fairly complicated, however; this limit is higher in some states, and if you are working and making some money, some of that income doesn't count towards the limit. (See our article on the SSI income limit for more information.) The SSI program also has asset limits.
If your income and assets are low enough to qualify for Supplemental Security Income (SSI), and you also worked long enough to qualify for Social Security disability insurance (SSDI), it's not unlikely you'll receive both types of benefits at once. Just keep in mind your SSDI payment is included in calculating your eligibility for SSI. In many cases, your SSDI payment will be so high you won't qualify for SSI.
If your SSDI benefit is under $750 per month (the current SSI monthly payment amount) and you qualify for SSI, you will receive an SSI payment. In other words, if your SSDI benefit is less than $750 per month, you can receive both SSI and SSDI benefits at once. For instance, if your SSDI payment is $500, and you have no other income, you would also receive a $350 SSI payment.
If you've been approved for SSDI but are within the five-month waiting period, you won't get an SSDI payment, but you could get SSI payments if you have little countable income. When you start receiving SSDI payments after the waiting period is over, you won't receive a higher monthly combined benefit than you would under the SSI program alone, so your SSI payment will be lowered by your SSDI payment to match the maximum SSI payment. For instance, if you receive $750 in SSI and then start to receive a $600 SSDI payment, your SSI payment would be reduced to $100.
Whether you apply for SSI, SSDI (also called SSD), or both, the Social Security office will decide whether your claim is concurrent, depending on your income and assets. The category of your disability claim will make no difference as to how the claim is processed at Disabiilty Determination Services. The same definition of disability and the same disability evaluation process is used for both programs.
The benefit to collecting SSI when you are collecting a low monthly SSDI benefit is that the SSI payment will raise your benefit up to $750 per month.
The benefit to being able to collect SSDI when you are eligible for SSI is that you may be eligible to get on Medicare as an SSDI recipient (although you must wait two years from when your SSDI eligibility begins).
In contrast, SSI recipients are eligible for Medicaid alone. While Medicaid does provide payment for more services than Medicare, more doctors accept payments from Medicare, so it can be easier to find a provider. For more information, see our article on getting Medicare or Medicaid while on disability.