Federal Guidelines
CMS Transmittal 1530 – Critical Care Visits and Neonatal Intensive Care (Codes 99291 - 99292) 
ICD-9-CM Official Guidelines for Coding & Reporting
Medicare Transmittal 1776/Shared E&M Billing
Federal Regulations for Teaching Physician Services (42 C.F.R. Part 415, Subpart D)
Medicare Claims Processing Manual, Chapter 12, Sections 100-100.2 - Teaching Physician Services
1995 Evaluation and Management Documentation Guidelines
1997 Evaluation and Management Documentation Guidelines
Draft 2000 Evaluation and Management Documentation Guidelines