The 555-foot-high (170-metre) marble and granite obelisk sustained cracks, loosened stones and lost mortar during a 5.8-magnitude earthquake in August 2011. The worst damage was at the top of the four-sided structure.
A reopening ceremony will be hosted by NBC "Today" show weatherman Al Roker. It will include remarks by Secretary of the Interior Sally Jewell and other officials, the National Park Service said in a statement.
Music will be provided by "American Idol" winner Candice Glover, the Army's Old Guard Fife and Drum Corps, the Navy Band and a children's choir.
Congress appropriated $7.5 million to repair the earthquake damage. The amount was matched by billionaire David Rubenstein, a Washington philanthropist.
The monument will be open for public touring after the ceremony, the statement said.
The monument to the first U.S. president, George Washington, was completed in 1884. It receives about 600,000 visitors a year.