BACKGROUND: Data on the real-world health care burden of COVID-19 in the United States are limited. OBJECTIVE: To compare health care resource use (HRU), direct health care costs, and long-term COVID-19-related complications between patients with vs patients without COVID-19 diagnoses. METHODS: Using IBM MarketScan Commercial Claims and Encounters and Medicare Supplemental and Coordination of Benefits administrative claims databases (January 1, 2018, to March 1, 2021), this retrospective, matched cohort study compared patients with a recorded COVID-19 diagnosis to control subjects with no recorded diagnosis for COVID-19, personal history of COVID-19, or pneumonia due to COVID-19. To capture typical health care utilization, the control group was analyzed in 2019 (prepandemic); their index date was assigned as 1 year before the index date (first observed COVID-19 diagnosis) of their matched COVID-19 patient. All patients had continuous health plan coverage for at least 6 months pre-index (baseline) and at least 6 months post-index (allowing censoring during month 6). Separately for commercial and Medicare cohorts, COVID-19 and control patients were matched 1:1 using propensity scores, number of followup months, and indicator of age 18 years or older. During each month of the 6-month follow-up, all-cause HRU, health care costs, and COVID-19-related complications were compared between patients with COVID-19 and controls. RESULTS: After matching COVID-19 and control patients 1:1, a total of 150,731 commercial matched pairs and 1,862 Medicare matched pairs were retained; baseline characteristics were similar between patients with COVID-19 and controls. Patients with COVID-19 and controls had mean ages of 38.9 and 39.7 years in the commercial cohort and 74.3 and 75.3 years in the Medicare cohort, respectively. In month 1 of follow-up, patients with COVID-19 relative to controls were significantly more likely to have at least 1 inpatient admission (commercial: 6.9% vs 0.5%; Medicare: 29.1% vs 1.3%; both P < 0.001) and at least 1 emergency department visit (commercial: 37.3% vs 3.4%; Medicare: 26.2% vs 4.1%; both P < 0.001). Total health care costs in month 1 were significantly higher among patients with COVID-19 than controls (mean differences: $3,706 for commercial; $10,595 for Medicare; both P < 0.001), driven by inpatient costs. Though the incremental HRU and cost burden of COVID-19 decreased over time, patients with COVID-19 continued to have significantly higher total costs through month 5 (all P < 0.001 for both commercial and Medicare). During follow-up, patients with COVID-19 had significantly higher rates of complications than controls (commercial: 52.8% vs 29.0% with any; Medicare: 74.5% vs 47.9% with any; both P < 0.001), most commonly cough, dyspnea, and fatigue. CONCLUSIONS: COVID-19 was associated with significant economic and clinical burden, both in the short-term and over 6 months following diagnosis. DISCLOSURES: Jessica K DeMartino is an employee of Janssen Scientific Affairs, LLC. Elyse Swallow, Debbie Goldschmidt, Karen Yang, Marta Viola, Tyler Radtke, and Noam Kirson are employees of Analysis Group, Inc., which has received consulting fees from Janssen Scientific Affairs, LLC. This study was funded by Janssen Scientific Affairs, LLC. The sponsor was involved in the study design, interpretation of the results, manuscript review, and the decision to publish the article.