My ex-wife keeps sending me bills for behavioral health for my child. But on these so called bills, that are handwritten by the Doctor's Office, they actually put my child's medical behavioral health diagnosis.

Is that a common practice or is it a violation of HIPAA?

"So-called" bills? These aren't bills from a Physician's Office. In this case your child is under age. You are getting the notification that a patient gets. If you don't want to know your child's diagnosis, contact the Physicians office and ask that it be omitted.

If your ex is sending you copies if what she has received there is no HIPAA violation. The doctor is communicating with her. It is her choice to communicate with someone else.

Agree, why do you not want to know what is wrong with your child ? Is the doctor handing this out to anyone else other than the child's parents ?

- This is also a two headed sword. Don't provide the diagnosis and the parent refuses to pay. We see it on AMHD now and then.