IMPORTANCE While telehealth use in surgery has shown to be feasible, telehealth became a major modality of health care delivery during the COVID-19 pandemic.OBJECTIVE To assess patterns of telehealth use across surgical specialties before and during the COVID-19 pandemic.

Given the US health care system mandates to minimize patient and clinician exposure to COVID-19, telehealth use across all specialties increased dramatically in the COVID-19 pandemic. Telehealth for preoperative and postoperative surgical follow-up patient visits had started to occur at low levels before the pandemic. The extent to which different surgical specialties were able to adjust to telehealth as the major modality of health care delivery remains unclear.This statewide cohort study aimed to determine how telehealth use patterns changed across surgical specialties before and during the COVID-19 pandemic. For the primary analysis, new adult outpatient visits with a surgeon (including colorectal surgery, general surgery, neurosurgery, obstetrics and gynecology, ophthalmology/ear, nose, and throat, orthopedics, plastic surgery, thoracic surgery, and urology) between January 5 and September 5, 2020, were identified from a large commercial insurance payer in Michigan. Patient visits were categorized as in-person office visits or telehealth visits using appropriate telehealth modifier codes. The pandemic was stratified into 3 periods based on national and state regulations, as well as trends in raw data: period 1 (pre-COVID-19 pandemic, January 5 to March 7), period 2 (early pandemic, March 8 to June 6), and period 3 (late pandemic, June 7 to September 5). The primary study outcome was telehealth conversion in 2020. This outcome was defined as the rate of new patient telehealth visits per week divided by the mean weekly new patient visit volume in 2019