It is required by the ACA now. It rolled out a couple of years ago. While mostly centered on fraudulently billing, it implicitly includes such things as training and education. It also discusses "harmonizing" peer review with current broadly accepted standards of care (i.e. need to align best practices with national standards, and report those doctors who practice outside those standards). At our hospital, all new hires (staff) are required to be reviewed and an evaluation submitted. We also amended our staff bylaws to make mandatory a one-year "probationary" period before you can be a fully-admitted member of the medical staff (used to be 3 months). I had to do this on a guy we hired despite the fact that he's been practicing without issues since the late 1990s.
http://healthaffairs.org/blog/2012/...d-licensure-systems-and-hospital-peer-review/
http://www.medpagetoday.com/PracticeManagement/PracticeManagement/39487
This is a double-edged sword. You're sticking your neck out (positive or negative) for someone you don't really know. People can fly under the radar in various ways and for a long time before real performance issues surface. And putting your name on a peer evaluation may have significant ramifications for yourself.
Caveat emptor.