I am not sure when I went on disability all I remember is my doctor handed me a signed piece of paper and sent me over to the business office to turn it in. It wasn't very long after that I received my placard for the car and started receiving a check from SSD. It had to be sometime around the time I knew I would have to start dialysis as soon I had a working access, which was September of 2003. I worked the rest of September and started dialysis in October.
The length of time will depend on your medical insurance to get you on Medicare, Social Security Disability, and your state to get you your disability placard. The biggest factor could be your insurance company. I have a wonderful insurance and I did not have do anything besides walk the signed piece of paper over to the business office. That was it, all of my medical records are available to anyone, with the right password, to see. So, I did not have to keep copies of anything. Good luck.