PURPOSE: To evaluate evidence on germline and somatic genomic testing for patients with metastatic prostate cancer and provide recommendations. METHODS: A systematic review by a multidisciplinary panel with patient representation was conducted. The PubMed database was searched from January 2018 to May 2024. Articles were selected for inclusion if they reported on patients with metastatic prostate cancer who received a germline or somatic genomic test and/or made comparisons between those tests, reported detection rates, prognostic information, or treatment implications. RESULTS: A total of 1,713 papers were identified in the literature search. After applying the eligibility criteria, 14 remained: eight systematic reviews and six clinical trials. RECOMMENDATIONS: Patients with metastatic prostate cancer should undergo both germline and somatic DNA sequencing using panel-based assays. These tests can guide the use of poly(ADP-ribose) polymerase inhibitors, which have a survival benefit in metastatic castration-resistant prostate cancer. In addition, germline testing may have screening implications for additional cancers for patients and cascade testing implications for family members. The data supporting when to perform repeat testing and optimal tissue type to use (eg, primary tumor