Based on the care provided in an office visit, a physician or other qualified healthcare provider uses evaluation and management (E/M) coding, also known as level of service (LOS), for reimbursement.1 A higher level of service means greater reimbursement. As of January 1, 2021, criteria for E/M coding changed across office visits to decrease documentation burden, simplifying criteria for medical decision making and enabling physicians to code based on visit time or degree of medical decision making required.2 In addition to the simplification and flexibility added, LOS 1 was removed as an available billing code for new patient visits.3 To determine how these coding criteria changes have influenced the proportion of office visits coded at each LOS, we reviewed 368 million office visits that occurred between January 1, 2017, and June 30, 2023.
For new patient visits, we found that, after the implementation of E/M changes on January 1, 2021, there was a decrease in the percentage of visits coded with LOS 2, from 13.1% in December 2020 to 4.5% in June 2023. The greatest percentage increase since the E/M coding changes was in visits coded at LOS 4, which increased from 33.3% to 45.1% of new patient office visits over the same period.
For established patients, we found there has been a steady increase in higher LOS code use since 2017, as shown in Figure 2. LOS 4 had the greatest change, going from 39.3% in January 2017 to 47.0% in December 2020 and then up to more than half of visits (50.3%) in June 2023. LOS 3 had the greatest decline in use, going from 48.3% of established patient visits in January 2017 to 42.9% in December 2020 and further decreasing to 39.7% in June 2023.