Purpose Multigene panels (MGPs) are increasingly being used despite questions regarding their clinical utility and no standard approach to genetic counseling. How frequently genetic providers use MGP testing and how patient-reported outcomes (PROs) differ from targeted testing (eg, BRCA1/2 only) are unknown. Methods We evaluated use of MGP testing and PROs in participants undergoing cancer genetic testing in the multicenter Communication of Genetic Test Results by Telephone study (ClinicalTrials.gov identifier: NCT01736345), a randomized study of telephone versus in-person disclosure of genetic test results. PROs included genetic knowledge, general and state anxiety, depression, cancer-specific distress, uncertainty, and satisfaction. Genetic providers offered targeted or MGP testing based on clinical assessment. Results Since the inclusion of MGP testing in 2014, 395 patients (66%) were offered MGP testing. MGP testing increased over time from 57% in 2014 to 66% in 2015 ( P = .02) and varied by site (46% to 78%; P < .01). Being offered MGP testing was significantly associated with not having Ashkenazi Jewish ancestry, having a history of cancer, not having a mutation in the family, not having made a treatment decision, and study site. After demographic adjustment, patients offered MGP testing had lower general anxiety ( P = .04), state anxiety ( P = .03), depression ( P = .04), and uncertainty ( P = .05) pre-disclosure compared with patients offered targeted testing. State anxiety ( P = .05) and cancer-specific distress ( P = .05) were lower at disclosure in the MGP group. There was a greater increase in change in uncertainty ( P = .04) among patients who underwent MGP testing. Conclusion MGP testing was more frequently offered to patients with lower anxiety, depression, and uncertainty and was associated with favorable outcomes, with the exception of a greater increase in uncertainty compared with patients who had targeted testing. Addressing uncertainty may be important as MGP testing is increasingly adopted.