In 2000, I became disabled. My employer had always offered disability coverage (through Unum) but did not absorb the monthly cost of around $7 (lol), so I paid it all the time. When disability started paying, it paid 70% of gross pay, which here in california meant that I was getting more take home pay than I had been making. In the meantime, I applied to Social Security, as required by the disability policy. I was approved on my initial claim submission within 90 days of its submission. I did my own paperwork rather than farm it out to an attorney. ONce approved by SS, the amount of their payment to me was deducted each month from the payment made by Unum, so never lost a buck. Twelve years later, I turned 65 and Social Security amounts changed a bit and the disability payment from Unum stopped and I had only SS from then until now.
Edit - Every three years Unum would require a new doctor's statement of my condition which never improved sufficiently enough for me to return to work.