I had a similar situation. My pcp that I see once a month for heartburn/acid reflux treatment also helped me quit smoking via nicotine patches. It was only a 30 day script for them though.

For 4 months I would see my doc and pay my copay but then at the end of the month I would get bills of $80-120 from the doc office. I paid it a couple times but decided to investigate I had already paid my deductible and could see no reason why I was getting billed. After arguing with the office staff they put me in touch with the billing lady and she tells me that I was being charged for extra "premium" services such as my Docs anti smoking program (which is a joke because we talked about it 1x for 5min and he just wrote me a script for patches) and a weight loss program. I was never explained that these were extra services by the doc or his staff. I called my insurance and they told me that I was covered for all of that and was basically getting ripped off.

I call the office billing lady again and she got very rude when i tried explaining what my insurance had told me and that I deserved a refund of at least $383. I also got upset and hung up. I called my insurance back and they said they would handle it.

The "extra" service fees stopped after that and I got a partial refund. The insurance agent told me that quite a few doc offices have been caught doing that. They are getting greedy since they make less per patient because of obamacare and other state health plans. She said most people just pay since you sometimes can't see your doc without paying then and there.

It's possible that you are being charged for something now that you thought was free then. Some doctors offices can be shady as hell. You should contact your insurance and the office that is billing you.