Enabling this feature will increase the office's efficiency as it will automatically update the appointment to "Paid in Full" when the payment pays the charges in full. The status will remain on "Balance Due" when a partial payment is received and there is still a balance due from the patient.
It can be set under Account > Account Settings > Medical Billing tab > Miscellaneous > Auto Set Billing Status > Change the billing status to "Paid in Full" and "Balance due" when the patient's payment is applied.