The three who face firing are Officer Caesar Goodson, who was driving the van where an autopsy determined Gray suffered fatal injuries; Lt. Brian Rice and Sgt. Alicia White, according to sources with knowledge of the case.
Officers Edward Nero and Garrett Miller, who made the initial arrest of Gray, face five days suspension without pay.
Officer William Porter, who was criminally charged with manslaughter by prosecutors, is not facing any internal discipline.
All six officers were criminally prosecuted last year on charges stemming from the in-custody death of Gray. After a series of mistrials and acquittals, Maryland States Attorney Marilyn Mosby dismissed the criminal charges.
The departmental charges come after investigators from the Montgomery and Howard county police departments finished their review of the case. The Baltimore Police Department asked them to conduct the investigation to avoid a conflict of interest.
All of the officers can accept the recommended punishment, or elect to contest the charges before an internal disciplinary panel, called a "trial board." A new state law makes trial boards open to the public.