You will be notified by SS about 4 months before you reach 65. This whole subject is fraught with mis-information. I am retired military so have TCFL which is great as I pay nothing on mnmedical bills. The last two years I have had spinal surgery to the tune of $70K+ twice, nothing out of my pocket, and the pharmacutical program is almost free. When my wife turned 65 we were deluged with advertising, they all get the mailing list from SS somehow. A lot of it was misleading, borderline illegal, and had one purpose; get you signed up for their expensive MEDIGAP policy. We compared pricing and coverage, went with United Health sponsered by AARP. They were honest, upright, and had the best pricing/benefit package including Part D. Sure glad we did; it is almost as good as my TCFL program.
As long as you qualify for SS you are qualified for MEDICARE. Beware if you are in a high income bracket as medicare is means tested and the more you make the more you pay; includes unearned income in the equation. When I was still working after 65 I was paying almost $400/mo for Medicare Part B.
On SS many folks do not realize they can work and make all you want if you wait till now 66/67 to draw. Also if your annuity is not at the max already, work at a job that pays your SS, as every year you work the annuity goes up until you reach the max. High earnings now replace those low earning years in your youth in the 35 year averaging in the equation. How all that works is also the best kept secret until you dig it out. Subject for a new thread.
Ron