Federal health officials are banning certain types of Medicare and Medicaid providers in three high-fraud cities from enrolling in the programs for the next six months.

The Centers for Medicare and Medicaid Services said the moratoriums will start Tuesday.

They will target home health care providers in eight counties in the Miami and Chicago areas. They also will target all ambulance providers in eight counties in the Houston area.

The ban also will extend to Children's Health Insurance Program providers in the same areas. The moratoriums were first reported by The Associated Press.

It's unclear how many providers will be shut out of the programs.

Top Senate Republicans criticized the agency in 2011 for not using moratoriums to combat an estimated $60 billion a year in Medicare fraud.