When I turned 65 I was automatically put on Medicare. I already was on Original Medicaid which paid 100% of everything. In CA Medicaid is called Med- Cal. So, when I turned 65 I got hundreds of phone calls and mail to join a Medicaire Advantage plan. Which I never did due to the rural county I live in and the fact I have to travel to a different county in order to access an Infectious Disease doctor as there is not even one in my county.
So...when I was switched to Medicaire being my primary and MedCal my secondary, they also threw in a prescription plan coverage called Wellcare. Started getting co-pays on prescriptions first time since started meds in 1997.
So..cannot tell you what happens if you decide to go on an Advantage Plan because I never did. I am hearing from my friends now that did pick a plan in order to get the freebies that it wasn't worth it and now they wish they never did.
In any case, you'll get some type of prescription coverage.

They get put in a plan covers both in an advantage plan the best of both and you can still see all your doctors free prescriptions free your not losing anything you'll just have both in one plan and no copays and you get your 170.00 back in your social security check each month it's well worth i know

You need part D Medicare for your prescriptions. Find out what your co pat will be. In Oregon we have Ryan White funds that buys our Medicare D policy for us

Medicare doesn't cover your partD plan that you pick covers 80% most states EOHHS drug assistance programs with Ryan White covers the rest check it out

I once upon a time used whale mart for my meds then suddenly the scripts disappeared from their system which left me in a real bind .
I got my id pcp to issue new scripts which I promptly took to Walgreens and only had an occasional problem but was resolved with a fone call or three .
Then a while I used the farma y at Publix then it was suggested by the nurse practitioner for diabetes that I get all my meds from one source and that's when my id PCP and social worker convinced me to go with Currant farmacy well as stated in an earlier I have been doing the mail order st hick over 10 years now ( mail order is actually a misnomer because the meds arrive by way of Ups within 3 days of ordering them ) .