You do have to be off for 6 months before benefits would start but I don't think you have to be off 6 months to start the process. I would have applied at the 6 month mark nearly precisely just by chance. Everything goes back to the "date of disability" and your date of disabiliyt has to be 6 months from your first check but you can be approved and waiting for the check as far as I can tell. The sooner you do it the sooner you'll get medicare; you have to be 2 1/2 years from date of disability. So my date of disability was August and my approval date April; I got Medicare 2 years after resigning my job and applying for Medicare because I had already waited 6 months.