Three relatives charged with helping a former city consultant launder $25 million in kickbacks in the massive CityTime payroll-system scam will plead guilty, court documents filed yesterday show.

Mark Mazer’s wife, Svetlana Mazer; mother, Larisa Medzon, and cousin, Anna Makovetskaya, are scheduled today to admit to their roles in the $500 million overbilling scheme, Manhattan federal prosecutors wrote.