According to a statement, President Bush was admitted to Houston Methodist Hospital last Friday for observation due to a persistent cough.
"It was subsequently determined he had a mild case of pneumonia, which has been treated and resolved," the statement said.
McGrath also added that the 41st president is "going to be fine."
Full statement released to ABC7NY:
"President George H. W. Bush was admitted to Houston Methodist Hospital on Friday for observation due to a persistent cough that prevented him from getting proper rest. It was subsequently determined he had a mild case of pneumonia, which was treated and has been resolved. President Bush is in very good spirits and is being held for further observation while he regains his strength."
In January, President Bush was admitted to the ICU at Houston Methodist Hospital with an acute respiratory problem.
He was released from the hospital on Jan. 30 after receiving treatment for more than two weeks. President Bush was joined in the hospital by his wife, Barbara, who also received treatment for bronchitis.
PHOTOS: Former President George H.W. Bush through the years