Systematic efforts are needed to prepare persons newly diagnosed with acute or chronic HIV infection to cope. We examined how patients dealt with this news, looking at how readiness to accept an HIV diagnosis impacted treatment outcomes, prevention of transmission, and HIV status disclosure. We examined vulnerability and agency over time and considered implications for policy and practice. A qualitative sub-study was embedded in the Tambua Mapema ("Discover Early") Plus (TMP) study (NCT03508908), conducted in coastal Kenya between 2017 and 2020, which was a stepped wedge trial to evaluate an opt-out HIV-1 nucleic acid testing intervention diagnosing acute and chronic HIV infections. Diagnosed participants were offered antiretroviral therapy (ART), viral load monitoring, HIV partner notification services, and provision of pre-exposure prophylaxis (PrEP) to their uninfected partners. Data were analyzed using thematic approaches. Participants included 24 individuals who completed interviews at four time points (2 weeks and 3, 6, and 9 months after diagnosis), including 18 patients (11 women and 7 men) and 6 partners (1 woman, 5 men, of whom 4 men started PrEP). Acceptance of HIV status was often a long, individualized, and complex process, whereby participants' coping strategies affected day-to-day issues and health over time. Relationship status strongly impacted coping. In some instances, couples supported each other, but in others, couples separated. Four main themes impacted participants' sense of agency: acceptance of diagnosis and commitment to ART; positive feedback after attaining viral load suppression; recognition of partner supportive role and focus on sustained healthcare support whereby religious meaning was often key to successful transition. To support patients with acute or newly diagnosed chronic HIV, healthcare and social systems must be more responsive to the needs of the individual, while also improving quality of care, strengthening continuity of care across facilities, and promoting community support.