Today, hospitals and doctors use a system of about 18,000 codes to describe medical services in bills they send to insurers. Apparently, that doesn't allow for quite enough nuance. A new federally mandated version will expand the number to around 140,000—adding codes that describe precisely what bone was broken, or which artery is receiving a stent. It will also have a code for recording that a patient's injury occurred in a chicken coop. Indeed, health plans may never again wonder where a patient got hurt. There are codes for injuries in opera houses, art galleries, squash courts and nine locations in and around a mobile home, from the bathroom to the bedroom. Some doctors aren't sure they need quite that much detail. "Really? Bathroom versus bedroom?" says Brian Bachelder, MD, a family physician in Akron, OH. "What difference does it make?"