The company said it will add 15 new employees in the 2,500 square-foot section of the campus.
Staff at headquarters has nearly doubled since 2007, when the company relocated to Chantilly, according to Citizant President Alba Aleman.
More than 40 new employees joined last year and the company expects to hire 25 more workers this year, it said in a release.
The company holds prime positions on information technology vehicles for the departments of Justice and the Treasury.
Last month, Citizant promoted Frank Nigro as vice president of its civilian agencies group.