Any Retired Federal employees on medicare?

Thanks for all the reply’s, it’s definitely a help. She has been researching this for some time, and it is very confusing. We both took a Medicare class about six months ago, but still didn’t get all our questions answered.
A bunch of people she used to work with did what it sounds like she needs to do. Keep the federal health coverage and do part B also.

DesertRat, I’m wondering why it takes two years to get accepted into part B?
Seems like they have it set up so you almost have to take it, so why so hard to get accepted? And I’m wondering if her current federal coverage will cover everything it used to while she waiting for part b to kick in?