Recent work vs duration of work
SSA applies two tests. The recent-work test looks at credits just before onset (for most people 31+, 20 credits in the last 10 years — the 20/40 rule). The duration-of-work test looks at lifetime credits, which increase with age until 40 credits. Your date last insured (DLI) is the last day you still meet the recent-work test. Onset after DLI generally means no SSDI (SSI may still be possible).
| Age at onset | Credits | Work |
|---|---|---|
| Before 24 | 6 credits in the 3 years before onset | 1.5 years |
| 24–30 | Credits for half the time since age 21 | Varies |
| 31–42 | Generally 20 credits (20/40 rule) | 5 of last 10 |
| 44 | 22 credits | 5.5 years |
| 46 | 24 credits | 6 years |
| 48 | 26 credits | 6.5 years |
| 50 | 28 credits | 7 years |
| 52 | 30 credits | 7.5 years |
| 54 | 32 credits | 8 years |
| 56 | 34 credits | 8.5 years |
| 58 | 36 credits | 9 years |
| 60 | 38 credits | 9.5 years |
| 62 to full retirement age | 40 credits | 10 years |
Credits are earned through covered wages or self-employment. Your date last insured is the last day you still meet the recent-work test.