BACKGROUND: Tuberculosis infection (TBI) and chronic hepatitis B virus (HBV) infection disproportionately affect non-US-born persons. Early identification and treatment are critical to reduce transmission, morbidity, and mortality, but little is known about screening in the United States. METHODS: We conducted a cross-sectional study in a large integrated California health system in September 2022 assessing TBI and HBV screening among persons aged ≥18 years who were born in countries with high TB burden (TB disease incidence rates ≥20/100 000 population) and/or HBV burden (hepatitis B surface antigen seroprevalence >2%). RESULTS: Of 510 361 non-US-born persons born in countries with high TB burden, 322 027 (63.1%) were born in countries with high HBV burden and 188 334 (36.9%) in countries with only high TB burden. Among persons born in countries with high TB and HBV burden, 29.6% were screened for TBI, 64.5% for HBV, and 23.4% for TBI and HBV; 9.9% had TBI and 3.1% had HBV infection. Among persons born in countries with high TB burden only, 27.9% were screened for TBI and 7.5% had TBI. CONCLUSIONS: Among non-US-born persons from countries with high TB and HBV burden, we found low screening rates and elevated prevalence of TBI and chronic HBV infection. Cotesting for TBI and HBV infection in non-US-born persons from countries with high TB and HBV burden might improve outcomes by identifying persons who warrant TBI treatment, HBV treatment, or HBV vaccination. Increased screening is the first step in reducing health inequities and overall disease burden.