Sent to collections prior to 90 days from date of service. Even the collection agency stated that they don't know why. Dr. Sanders office only refers you to billing. I spent over an hour on hold to also be told by Dr Sanders own billing person that she doesn't know why it was sent to collections either. And then transferred me to a supervisor that never answered. VERY SHADY. VERY VERY SHADY. Beware. Ask for a predetermination and pay before you leave the office. Don't let them tell you to wait for a bill. This takes way too much time to straighten out. Oh, btw. I NEVER GOT A BILL FROM DR SANDERS!!!!