The officials said the four dead in Wednesday's shooting include the shooter.
One of the officials, citing official internal Justice Department updates, says 14 others were hurt.
The officials spoke on condition of anonymity because they were not authorized to release information by name.
The Texas Army base was the scene of a mass shooting in 2009. Thirteen people were killed and more than 30 wounded in what was the deadliest attack on a domestic military installation in history.