What does the DO after a doctors name mean?

It means that he or she is a Doctor of Osteopathic Medicine. The "DO" degree is conferred upon successful completion of a medical education at any of the Osteopathic Medical Schools in the United States. The "MD" degree is conferred upon successful completion of a medical education at any of the Allopathic Medical Schools. If you are a patient you need not worry about which initials follow a doctor's last name. MDs and DOs work side by side in every state and corner of the country. There is no substantive difference between the two.