Inclusion Criteria:

* Participants must meet all the following criteria:

* Written informed consent and HIPAA authorization obtained prior to any study-related data collection.
* Age ≥18 years at the time of enrollment.
* Recipient of a kidney transplant, including:
* Primary or repeat kidney transplantation
* Living-donor or deceased-donor transplantation
* At 1 month post-kidney transplant at the time of enrollment.
* Receiving maintenance immunosuppressive therapy per institutional standard of care.
* Selected by the treating provider to undergo TRAC testing as part of usual post-transplant clinical monitoring.

Exclusion Criteria:

* Recipient of a combined organ transplant involving a non-renal solid organ (e.g., kidney-liver, kidney-heart) and/or islet cell transplantation.
* History of prior non-renal solid organ transplantation or islet cell transplantation.
* Known pregnancy at the time of enrollment.
* Known active viral infection at enrollment with any of the following:
* Hepatitis B surface antigen (HBsAg)-positive
* Hepatitis B virus (HBV) nucleic acid testing (NAT)-positive
* Human immunodeficiency virus (HIV) infection or HIV NAT-positive
* *Known active BK virus-associated nephropathy (BKVAN) or CMV disease at the time of enrollment.
* Medical, psychiatric, or social condition that, in the opinion of the Investigator, would interfere with the participant's ability to provide informed consent or comply with study procedures.
* Concurrent participation in another investigational biomarker study designed to evaluate clinical utility of post-transplant molecular diagnostics.

* Participants with asymptomatic or low-level viral replication detected during routine clinical monitoring are eligible, provided there is no evidence of established CMV disease or BK virus-associated nephropathy at enrollment.

Note: Other protocol defined Inclusion/Exclusion Criteria may apply.

Eligibility last updated 03/23/2026. Questions regarding updates should be directed to the study team contact.