Laws vary from state to state, but I'm not aware of any laws stating how to balance bill patients.
We use a 3 statement method:
1. Send a detailed explanation of what is owed and why
2. Send a second notice/friendly reminder
3. Send a final notice
The secret is to bill regularly. Patients who know the statement will come again in 30 days are more likely to pay than if they think another statement may not come. Also, don't threaten collections unless the provider is going to send the patient to collections. We have providers who DO NOT use collections. They simply bill, and then write off if unpaid. So we say something like "Final Notice - Please remit payment in 10 days"
We have some offices that only use a 2 statement system and then use something called Profit Recovery. It's the first step in a collection system from Transworld. It works better because their patients are not usually return patients so they won't see them again. Instead of wasting 90 days, they go into collections thru Profit Recovery in 60 days. It works well. There is no cookie cutter method. You need to develop a system based on the provider's office and needs.