Question: What is meant by the review of systems (ROS) levels? California Subscriber Answer: Four ROS levels contribute to the level of history selected for an E/M service code. ROS progresses from -nonavailable- or -nonapplicable- to -problem-pertinent- to -extended- and -complete.- In a problem-pertinent ROS, your orthopedist asks questions about the system directly related to the problem identified in the history of present illness (HPI). When the physician asks about a limited number of additional systems, he meets the criteria for an extended ROS. Important: Extended ROS documentation must include positive responses and pertinent negatives for two to nine systems, according to both the 1995 and 1997 Documentation Guidelines for E/M Services. A complete ROS requires inquiring about all organ systems. The physician must review at least 10 organ systems and individually document those systems with positive responses and pertinent negatives. Tip: For the remaining systems, the orthopedist can use a notation to indicate that all other systems are negative. Without such a notation, he must individually document at least 10 systems for the documentation to support a complete ROS.