Chart review was performed to identify patients with cancer who met the following pathology-based Kaiser Permanente Northern California guidelines for referral for genetic counseling: invasive breast cancer, younger than age 40; nonmucinous epithelial ovarian, fallopian tube, or peritoneal cancer, younger than age 60; women with synchronous or metachronous primary cancers of the breast and ovaries; and male breast cancer. We assessed compliance with referral guidelines