Office visits are the bread and butter of many physicians' practices. Medicare pays for more than 200 million of them a year, often to deal with routine problems like colds or high blood pressure. Most require relatively modest amounts of a doctor's time or medical know-how. Not so for Michigan obstetrician-gynecologist Obioma Agomuoh. He charged for the most complex — and expensive — office visits for virtually every one of his 201 Medicare patients in 2012, his billings show. In fact, Medicare paid Agomuoh for an average of eight such visits per patient that year, a staggering number compared with his peers.