Yes. If you become disabled after filing early for retirement benefits, you may be able to change to Social Security Disability Insurance (SSDI). Similarly, if you retire early but belatedly discover that an existing condition might have qualified you for a higher disability benefit, you may be able claim it retroactively.
For the vast majority of disability recipients, who claim SSDI before retiring, the question is moot. If you file first for SSDI, at any age, the benefit is calculated as if you were at full retirement age (FRA) — the age at which you qualify for 100 percent of the benefit amount determined by your lifetime earnings. Once you reach FRA, your disability benefit automatically converts to a retirement benefit, in most cases at the same amount.
But suppose you started Social Security at 62, for reasons unrelated to health, taking a reduction in benefits for filing before full retirement age (which is 66 and 4 months for people born in 1956, two months later for those born in 1957, and gradually rising to 67). Six months later, you are diagnosed with kidney disease. You can file for SSDI, and if the claim is approved, you will get a higher benefit, backdated to when you applied for disability. (You will still not get your full retirement benefit, but the “reduction factor” for early retirement will shrink from four-plus years to just the period when you were only eligible for retirement benefits.)
Or, say you claim Social Security retirement benefits at 62 because you can no longer work due to failing eyesight. Your doctor had already diagnosed macular degeneration, but you only learn later that this could have qualified you for SSDI. If you can prove your disability began before you took early retirement, Social Security will retroactively pay up to 12 months of the difference between what you’ve received so far and what you would have gotten under SSDI. (If you applied for disability within a year of starting Social Security, this could mean being restored to your full retirement benefit; after a year, there will be some reduction.)