PurposeParticipants in the 100,000 Genomes Project, a clinical/research initiative delivered through the UK National Health Service, were offered screening for “additional findings” (AFs): pathogenic/likely pathogenic secondary findings in genes associated with familial hypercholesterolemia or a cancer predisposition syndrome. Understanding the psychological and behavioral responses to secondary findings can inform the clinical utility of a search and disclose policy. MethodsThirty-two adult AF recipients took part in semi-structured interviews analyzed using deductive and inductive thematic analysis. ResultsFive themes were constructed: cognitive responses to an AF, emotional and psychological responses, personal control, perceived risk of AF-associated disease, and family implications. Many participants had misunderstood or incompletely remembered consent for AFs, and most were surprised or shocked to receive an AF. Although many ultimately appreciated knowing about the risk conferred, some struggled to make sense of their disease risk, which complicated decision making about risk management, particularly for women with a BRCA AF. Recipients sought control through seeking clinical evaluation and information, and informing relatives. Difficulties with conceptualizing risk and lack of AF-associated disease family history meant that some hesitated to inform relatives. ConclusionGenome sequencing programs offering secondary findings require attention to consent processes. Post-disclosure care should aim to promote recipients’ perceived personal control.