Bush spokesman Jim McGrath said Tuesday that the 92-year-old Bush is sitting up, talking with physicians, staff and visitors, and returning phone calls.
The nation's 41st president also is working with physical therapists to help him regain strength.
Bush was admitted to Houston Methodist Hospital on January 14 for breathing difficulties blamed on pneumonia. He later was moved to intensive care when doctors inserted a breathing tube.
He was moved from the ICU on Monday afternoon. Former first lady Barbara Bush was discharged from the same hospital Monday after five days for treatment of bronchitis. McGrath says she returned as a visitor today to be with her husband of 72 years.