Adults more than and equal to (≥) 18 years of age at index date.
Diagnosis of comorbid ESRD or comorbid severe CKD prior to the index date.
* If ESRD (including participants on peritoneal dialysis or hemodialysis): participant diagnosed with ESRD confirmed by an estimated glomerular filtration rate (eGFR) less than (\<) 15 milliliters per minute per 1.73 square meters (mL/min/1.73m\^2).
* If severe CKD: participant diagnosed with severe CKD confirmed by an eGFR of 15 to \<30 mL/min/1.73m\^2 at index.
Participant has undergone solid organ transplant (SOT) or hematopoietic stem cell transplantation (HSCT) before index date.
Participant was diagnosed with refractory (with or without resistance) CMV during the latest post-transplant period.
Participant initiated treatment with maribavir in routine practice within the eligibility period and received at least 1 dose of maribavir.
Informed consent provided (where required by local regulations) before data collection commences.
