PURPOSE:Little is known about the factors that influence patients' preferences for the return of incidental findings from genome sequencing. This study identified attributes of incidental findings that were important to patients and developed a discrete-choice experiment instrument to quantify patient preferences. METHODS:An initial set of key attributes and attribute levels was developed from a literature review and in consultation with experts. The attributes' salience and communication were refined using focus group methodology (n = 12) and cognitive interviews (n = 6) with patients who had received conventional genetic testing for familial colorectal cancer or polyposis syndromes. The attributes and levels used in the hypothetical choices presented to participants were identified using validated experimental design techniques. RESULTS:The final discrete-choice experiment instrument incorporates the following attributes and levels: lifetime risk of disease (5, 40, 70%); disease treatability (medical, lifestyle, none); disease severity (mild, moderate, severe); carrier status (yes, no); drug response likelihood (high, moderate, none); and test cost ($250, $425, $1,000, $1,900). CONCLUSION:Patient preferences for incidental genomic findings are likely influenced by a complex set of diverse attributes. Quantification of patient preferences can inform patient-provider communication by highlighting the attributes of incidental findings that matter most to patients and warrant further discussion.