Introduction: Routine follow-up (f/u) leads to better BP control and CV outcomes in individuals with hypertension (HTN). Guidelines suggest newly treated patients f/u within 1-2 months after initiating treatment. Few real-world studies have assessed the timing of actual f/u care and concordance with guidelines. Methods: We performed a cohort study of adult Florida Medicaid (2012-2021) or Medicare (2012-2017) recipients with newly treated HTN in the OneFlorida+ Consortium. Patients were aged ≥18 y, diagnosed with HTN, who filled ≥1 first-line antiHTN drug with no evidence of antiHTN use in the year prior, and had ≥1-year of continuous insurance enrollment prior to first antiHTN fill (index date). Occurrence and timing of f/u were determined by identifying post-index outpatient encounters with a HTN diagnosis. Cox regression models were used to assess association of age-adjusted sex and race with time-to-first f/u, separately in Medicaid and Medicare recipients. Results: We identified 52,712 new antiHTN users in the Medicare population (mean ± SD age, 72 ± 19.4 y; 53.4% women; 15.4% Black). Among the 14,608 (27.7%) patients who had a f/u visit, median time-to-f/u was 100 (IQR: 21, 145) days. Among 64,586 new antiHTN users who were Medicaid recipients (age, 47 ± 14.3 y; 59.9% women; 30.4% Black), 28,304 (43.8%) had a f/u visit with median time of 56 (IQR: 32, 231) days. Among Medicare-insured, Whites were 11% (HR 1.11; 95% CI, 1.07-1.16) more likely to have a f/u visit than Black individuals, and among Medicaid-insured, Whites were 5% (HR 1.05; 95% CI, 1.02-1.08) more likely; sex was not associated with likelihood of f/u in either cohort after age-adjustment. Conclusions: Few patients had a f/u within 1 year of initiating antiHTN therapy, and, of those with a visit, fewer than half did so within 2 months, even when using a liberal definition of f/u (i.e., any outpatient encounter with HTN diagnosis). Such delays in care may prevent rapid BP control and expose individuals to higher CVD risk. We also observed small, but significant disparities among White and Black individuals. These findings may help explain well-known disparities in BP control and related adverse sequelae of uncontrolled HTN.