I use an employee in house and Caretracker Billing. Caretracker is a Harris computing company and does interact with AC. It has worked fairly well but has a few issues. The biller states that this is much easier than when we previously used Kareo. It is much more expensive than Kareo. BAse rate of $429 vs $288. The inferface for AC in the demographics is one way only. Example, if you enter a new pt in AC it does not go to Caretracker. If you enter a patient in Caretracker then it sends this information to AC. Caretracker was able to help us get the names and demographics imported. We have had some duplicate charts because things were not exactly the same in AC as Caretracker. Overall, it has saved some time for the billing person and is nice to have her in house not paying the going rate for collections and someone local to answer questions for the patients. Let me know if you have any specific questions.