Chapman said he is receiving dialysis treatments and will continue to play Grizzwald on the NBC sitcom. He and Kevin Brown, as the character Dot Com, appear as the two-man entourage for a hapless comedian played by Tracy Morgan.
Chapman, 35, is married and has two children. He is scheduled to appear on "The Dr. Oz Show" Tuesday to discuss his health.
Chapman said Monday he was diagnosed a decade ago with high blood pressure and learned two years ago that he was suffering from kidney disease. He gets dialysis treatments three times a week.
The actor said he will have the organ transplant when a match is found and he's at an acceptable weight.
"I'm a little nervous about the process, but I'm definitely willing and able," Chapman said from New York.