BCBS and Medicare

I am a dependent of a federal employee who has BCBS and have used this coverage for several years.  I have an excellent relationship w/ my doctor who is a network provider.  Next year I will be 65 and I was expecting to have this plan as long as my husband is employed.  Last week I got a brochure from BCBS "2016 Medicare at a Glance."  It doesn't say much but has comparisons of BCBS to Medicare.  Will I still be on my husband's plan or will it change when I am 65?  My doctor does not accept Medicare and I want to continue w/ our current plan.