The purpose of this study is to compare the difference in medication dosage and total daily dose necessary of Astagraf XL® in order to reach therapy goal, when taken with other medications that are routinely used for kidney transplantation, which may stop the development of a substance that can cause long-term damage to the transplanted kidney. African American kidney transplant patients aged 18 and above who are underwent a kidney transplant are eligible to participate. The duration of the study is 3 months.