Introduction: Adult hepatitis B vaccination coverage in the United States remains low despite updated national recommendations supporting universal adult immunization. Many adults remain unaware of their susceptibility to hepatitis B virus (HBV) infection. This quality improvement (QI) study evaluated a stepwise “Offer–Offer–Test–Vaccinate” workflow designed to improve hepatitis B vaccine uptake among vaccine-hesitant adults in a primary care setting. Methods: This retrospective QI study was conducted at a single primary care clinic in Rochester, Minnesota. Adult patients (≥19 years) seen between October 1, 2022, and October 1, 2024, were routinely offered hepatitis B vaccination during rooming. Two participating physicians implemented an enhanced workflow in which patients who declined vaccination were counseled and then offered serologic screening using the 2023 CDC-recommended triple panel (HBsAg, anti-HBs, and total anti-HBc). Patients with negative serology were notified via the patient portal and reoffered vaccination along with a link to the CDC Vaccine Information Statement. The primary endpoint was initiation of the hepatitis B vaccine series following receipt of negative serology results. Preliminary series-completion data through October 1, 2025, were also assessed. Results: Among 501 eligible adults, 104 (20.8%) accepted vaccination at the initial offer. Of the 397 who declined, 106 (26.7%) agreed to serologic testing; 91 (85.8%) were seronegative. Among seronegative patients, 41 (45.1%) subsequently accepted vaccination. Integrating serologic testing increased overall vaccination uptake from 20.8% to 28.9%, an absolute increase of 8.2 percentage points and a relative increase of 39.4%. Approximately 2.6 serologic tests were required to generate 1 additional first-dose vaccination. Preliminary series-completion rates were 74.0% among those vaccinated at the initial offer and 87.8% among those vaccinated following serologic testing. Discussion: In this primary care setting, incorporating serologic testing into the workflow was associated with modestly improved hepatitis B vaccination uptake among vaccine-hesitant adults. Serologic results may help re-engage patients by providing personalized immunity information. Implementation considerations include staffing needs, laboratory access, patient portal engagement, and insurance coverage. Conclusion: The “Offer–Offer–Test–Vaccinate” strategy was associated with a modest increase in hepatitis B vaccine uptake among hesitant adults. This EMR-integrated, stepwise approach may offer a feasible and scalable strategy to reduce missed vaccination opportunities and support HBV prevention in adult primary care.