RecruitingDiagnostic testValidation of Donor-Derived Cell-Free DNA (Dd-cfDNA) for Kidney Transplant MonitoringThe goal of this observational study is to learn if the donor-derived cell-free DNA (dd-cfDNA) test can assess rejection in kidney transplant recipients. Participants will have blood and urine collected at their study visit. Researchers will compare results of the GraftAssureDx to rejection detected by standard-of-care graft biopsies.