Steph,
Medicare advantage plans may be premptively raising rates in light of proposed fed subsidy cuts.
I know when my folks had option to transition from HMO supplemental, numerous "in the know" folks advised going with traditional medicare and adding supplementals to that.
$400/mo doesn't sound so bad when I consider I am 43, extremely healthy and my HMO is 270/mo without prescription coverage or dental.
I am investigating higher deductible plans and health savings account which can change premiums quite a bit. Might make sense for others.
Your husband's HMO sounds like a steal..or a typo

Ok..must be a Medicare supplemental?
Mary Anne,
Did you have to pay for Herceptin from the beginning? Did you talk to Genentech about support?