Not on MTX also, at the same time?
As for insurance, I almost cried when I first went to fill by Enbrel script the first time. My pharmacist called me and asked if I was sure I wanted to fill it because it would be very expensive - insurance would not pay anything. I asked how much and he said "eighteen ninety-five", and I was like "oh, $20? That's no trouble", and he said "no, $1,895.00".
Turns out my insurance would ONLY pay if I ordered the Enbrel from one of three approved pharmacies in the country. The insurance company had "pre-purchased" a bulk amount of Enbrel at a discounted price and distribute it ONLY through these three companies. Through these pharmacies I pay $10 per refill (i.e. $10 per month).
But, it took me two weeks or so to figure this out - nobody told me anything! And then it took like two months for the mail order pharmacy to get their act together and actually send me the stuff. It was a very very frustrating time in my life because the first "free" shot of Enbrel I took at the doctor's office (after years of MTX, Prednisone, Celebrex, blah blah blah blah) worked instantly like magic - and once you go off Enbrel for even a short time, it might not be as effective when you start back up...
So, try calling your HMO and asking them about stuff like this. Also, it might be cheaper to buy insurance that DOES have foresight like mine (BCBS) - my insurance costs are significantly less than buying Enbrel out of pocket.
Arthritis (poss. RA) - Doc scripts: Enbrel 50 autoinjector, Methotrexate 5 pills/week, Folic acid.