David Letterman is gearing up for a visit to pal Regis Philbin.

Letterman will appear on “Live with Regis & Kelly” April 30, the first day of the all-important May sweeps period.

It will be Letterman’s first visit to “Live” (9 a.m./Ch. 7) in three years, when he appeared on the show the day Philbin returned from heart-bypass surgery.