When a patient is seen by a physician extender without the direct involvement of the supervising physician, the visit is reimbursed at 85% of the physician fee. If, however, there is a DOCUMENTED "face-to-face" encounter between the physician and patient (ie "I have seen the patient and agree with the documented findings") then the visit is reimbursed at 100% of the physician fee.
Source
Mattu, A. et al. "Understand the Documentation Requirements of Midlevel Practitioners" Avoiding Common Errors in the Emergency Department