99213, S39.012A, W01.0XXA, Y92.030
Rationale: The patient is an established patient. In the CPT® Index look for Established Patient/Office and/or Other Outpatient/Office Visit. You are referred to 99211-99215. An established patient visit requires 2 of 3 key components. The provider documents an Expanded Problem Focused History (brief HPI, pertinent ROS, and no PFSH), a Problem Focused Exam (1 affected organ system, musculoskeletal) and Low MDM (New Problem to examiner, no additional work-up, 0 data points, and acute complicated injury, e.g., simple sprain). Review codes to choose the appropriate level of service. Code 99213 is the correct code. Lower Back Muscle Strain was the provider's diagnosis. In the ICD-10-CM Alphabetic Index look for Strain/low back. You are referred to S39.012-. Tabular List shows that a 7th character is reported. A is reported for the initial encounter. Next go to the External Cause of Injuries Index. Look for Slipping (accidental) (on same level) (with fall)/on/surface (slippery) (wet) NEC. You are referred to W01.0-. In the Tabular List placeholders of X are needed for the 5th and 6th characters. The 7th character is reported with A to indicate initial encounter. Next look for Place of occurrence/residence/apartment/kitchen. You are referred to Y92.030. Review the code in Tabular List to verify accuracy.