This is only MY experience, but here goes. The doctor has a fee schedule that should be compared with e.o.b.s from all of the insurance companies he/she bills. The fee you charge should be more than the highest allowed amount per charge.
Example:
Blue Cross allows $30.56 for 99202
Blue Shield allows $72.45 for 99202
Medicare allows $40.25 for 99202
Aetna allows $56.40 for 99202
Your fee should be at least $73.00. The allowed amounts are determined by the insurance companies and are based on a survey they do among providers for particular codes. If your doctor is the one charging $25.00 for a 99202, he/she will blow the average and the reimbursement for all the doctors in your area will go down.
Medicare will always be your touchbase, and I've read on here before to charge the medicare allowed + 30%. It's a good place to start, but if the doctor has been in business a while, you have a greater resource for information. Medicare is a good payer, but they are not the BEST payer. Most insurance companies can give you the allowed amounts via fax or e-mail as well. I have found that the faster way is to just audit e.o.b.s you already have.
I hope this advice is sound (Linda and Michele) and that it at least helps you to start!
Dina