I used to have a billing service and I have asked them to do this years ago with no success. the answer was always it is illegal and they can not do that.
I started my own billing in january of 2011. I have been using this policy since July of 2011. I Belive that was the best thing I have ever done in my pratice. Here what you need to do:
1) have the patient sign a form stating that he understand he will be charged a an interst(1.5%-2%)per month rate on any unpaid balance. As well as a late fee of ($20-$25) if not paid within 14-21-days.
2) add a note indicating the same on your billing statment each month.
At this point will become 100% legal in any state I have discussed this with a lawyer.
Off course you can easly set up a flate late fee only.
My idea about the high interest rate and late fee is to force the patient to pay as soon as possible if using his credit card if he has to. If the fee is too small like leslie $5 dollar they will not thing about payment promptly.
Once the patient signs the form at the first office visit. He will pay attentin to your bill like his electric bill and phone bill.
Be carefull not to charge any fee or interest on claim not cleared by insurance yet. I mean sometimes the insurance take 2-3 months before paying there part or they will refered to patient responsibility . Only then it will become 100 % legal to charge them.
After I noticed a success . I decided to have every patient old or new to sign this form as updated financial policy every years and I will keep a copy in AC.
For patient who has no insurance they will stop coming to you bytheself without the legal hassel of discharging them.
I hope this will help
Try it . If you have more questions please let me know.