The 30-second version
- SSDI pays on the Wednesday schedule based on your birthday. Funded by FICA. Requires a work history.
- SSI pays on the 1st of each month. Funded by general tax revenue. No work history required, but strict resource limits.
Pay date
SSDI follows the Title II schedule: 2nd, 3rd, or 4th Wednesday of each month, based on the beneficiary's date of birth. SSI pays on the 1st of each month, or the prior business day if the 1st is a weekend or holiday.
Pay amount
SSDI is based on your earnings record (same formula as retirement). Average SSDI in 2026 is about $1,580 per month. Maximum is around $3,900. SSI is a flat federal amount adjusted for state supplements: $967 federal maximum for an individual, $1,450 for a couple. Most states add $0-$200 supplement.
Medicare and Medicaid
SSDI recipients become Medicare-eligible 24 months after benefits start. SSI recipients are usually Medicaid-eligible automatically in most states (Section 1634 states), but Medicare eligibility kicks in at 65 or after a separate disability rule.
Can you receive both?
Yes. About 1 in 7 SSI recipients also receive SSDI. The two checks deposit on different dates per the schedules above. The SSDI amount usually reduces SSI dollar-for-dollar above a small unearned-income exclusion ($20 per month), so total income from both is capped near the SSI maximum unless you have other countable income.
Switching at FRA
SSDI automatically converts to Social Security retirement at your Full Retirement Age. The amount stays the same; the legal classification changes. SSI does not convert, it remains a separate benefit indefinitely.