Mizeur, who represents Takoma Park and Silver Spring in the state House of Delegates, confirmed she will make the announcement at American Legion Post 41 in Silver Spring. She did not disclose who her running mate is.
The Montgomery County Democrat will face Attorney General Doug Gansler and Lieutenant Gov. Anthony Brown in the state Democratic primary in June.
Gansler last month tapped state Del. Jolene Ivey (D-Prince George’s County) as his running mate. Howard County Executive Ken Ulman in June joined Brown’s campaign after he abandoned his own gubernatorial bid.
Mizeur could become the country’s first openly gay governor if Maryland voters elect her to succeed Gov. Martin O’Malley.