This multi-center study aims to enroll 100 patients (10-15 at Fairview-University Medical Center) and is designed to test the safety, tolerance, efficacy, and concentration of drug in the blood after dosing of investigational mycophenolate mofetil (MMF) oral suspension in pediatric kidney transplant patients. Children who are at least 3 months of age and weigh 5.4 or more kilograms and who have received a first or second kidney transplant will be eligible for this study. Participants will receive oral study medication twice daily for 36 months.