ImportanceFor patients discharged from the emergency department (ED), timely outpatient in-person follow-up is associated with improved mortality, but the effectiveness of telehealth as follow-up modality is unknown.ObjectiveTo evaluate whether the rates of ED return visits and hospitalization differ between patients who obtain in-person vs telehealth encounters for post-ED follow-up care.Design, Setting, and ParticipantsThis retrospective cohort study included adult patients who presented to either of 2 in-system EDs of a single integrated urban academic health system from April 1, 2020, to September 30, 2021; were discharged home; and obtained a follow-up appointment with a primary care physician within 14 days of their index ED visit (15 total days).ExposuresIn-person vs telehealth post–ED discharge follow-up within 14 days.Main Outcomes and MeasuresMultivariable logistic regression was used to estimate the odds of ED return visits (primary outcome) or hospitalization (secondary outcome) within 30 days of an ED visit based on the modality of post–ED discharge follow-up. Models were adjusted for age, sex, primary language, race, ethnicity, Social Vulnerability Index, insurance type, distance to the ED, ambulatory billing codes for the index visit, and the time from ED discharge to follow-up.ResultsOverall, 12 848 patients with 16 987 ED encounters (mean [SD] age, 53 [20] years; 9714 [57%] women; 2009 [12%] Black or African American; 3806 [22%] Hispanic or Latinx; and 9858 [58%] White) were included; 11 818 (70%) obtained in-person follow-up, and 5169 (30%) obtained telehealth follow-up. Overall, 2802 initial ED encounters (17%) led to returns to the ED, and 676 (4%) led to subsequent hospitalization. In adjusted analyses, telehealth vs in-person follow-up visits were associated with increased rates of ED returns (28.3 [95% CI, 11.3-45.3] more ED returns per 1000 encounters) and hospitalizations (10.6 [95% CI, 2.9-18.3] more hospitalizations per 1000 encounters).Conclusions and RelevanceIn this cohort study of patients in an urban integrated health care system, those with telehealth follow-up visits after an ED encounter were more likely to return to the ED and be hospitalized than patients with in-person follow-up. The use of telehealth warrants further evaluation to examine its effectiveness as a modality for continuing care after an initial ED presentation for acute illness.