Background: Current real-world data on healthcare utilization (HCU) and costs of common first-line (1L) follicular lymphoma (FL) regimens, including obinutuzumab (G), remain limited. The aim of this study was to examine real-world HCU and costs for the most common National Comprehensive Cancer Network (NCCN)-recommended 1L FL treatments. Methods: This was a retrospective cohort study using administrative claims data from the IQVIA PharMetrics Plus and IBM MarketScan Commercial and Medicare Supplemental databases. We identified patients (pts) ≥18 years, who had ≥1 inpatient claim or ≥2 outpatient claims, with a diagnosis of FL from February 1, 2015 to March 31, 2020, and had received 1L FL treatment (per NCCN guidelines) between February 1, 2016 and September 30, 2019. The first claim for FL treatment was the index date. All pts had ≥12 months of pre- and ≥6 months of post-index continuous enrollment in medical and pharmacy benefits. Pts with other primary cancers, FL treatment, or stem cell transplant during the pre-index period, and clinical trial participation or end-stage renal disease during the study period were excluded. All-cause HCU and costs (2020 USD) per pt during the 6-month post-index period were reported for the five most common 1L FL regimens (only complete NCCN regimens were considered). Results: Overall, 1991 pts met the eligibility criteria, and 53% were male. The mean (standard deviation [SD]) age and Charlson Comorbidity Index at index were 58 (10.4) years, and 1.7 (1.0), respectively. The most common 1L regimens were rituximab-bendamustine (R-benda; n=818 [41.1%]), R-monotherapy (R-mono; n=592 [29.7%]), R-CHOP (n=461 [23.2%]), G-benda (n=86 [4.3%]), and R-CVP (n=34 [1.7%]). The proportion of pts who had ≥1 hospitalization or an emergency room visit was highest with R-CHOP (26.7% and 33.6%, respectively) and lowest with R-mono (11.3% and 18.1%, respectively). Mean (SD) all-cause total healthcare costs were highest with R-benda and G-benda, followed by R-CHOP, R-CVP, and R-mono (Table). Mean (SD) all-cause medical and FL treatment costs (drug and administration) were highest for R-benda ($174,407 [$110,520]; $135,520 [$96,492]) and lowest for R-mono ($87,368 [$83,910]; $54,271 [$40,433]). Conclusions: This real-world study provides an update on HCU and costs among pts initiating current NCCN-recommended 1L treatment for FL. Unadjusted 6-month total healthcare costs were highest with R-benda, followed by G-benda, while the lowest costs were seen with R-CVP and R-mono. Future studies with adjustment for pt characteristics are needed to compare HCU and costs between FL regimens.