But it is not making the change because of privacy issues or safety, the two main complaints that have plagued the machines and the agency since they were introduced in 2010.
The reason for the move, said the TSA, is operational efficiency.
"TSA is strategically reallocating backscatter advance imaging technology units in order to allow for expanded use of advance imaging technology units at other airports," said TSA spokesman David Castelveter.
The machines with backscatter technology are being removed from Los Angeles International, New York's John F. Kennedy and LaGuardia airports, Boston Logan, Charlotte Douglas and Orlando International, and relocated to smaller airports, Castelveter said. He said it was yet to be determined which smaller airports would get them.
The millimeter wave units that are arriving in the larger airports use a different type of technology. The machines do produce different types of images, but the customer experience is the same. Millimeter wave produces a generic outline of the passenger being scanned, while backscatter is more specific. The TSA maintains that with backscatter technology, the officer doing the screening cannot identify the person being scanned and the image is immediately discarded.
"It's not feasible to have the two different types of machines in the same airport," Castelveter said. The two machines require different training and maintenance. While the agency has additional millimeter wave machines to deploy, it does not have additional units using the backscatter technology.
No matter the technology, the machines still have their detractors.
"It seems that the TSA is wasting millions of dollars on fancy equipment that could be better served deploying more effective security screening techniques," said Brandon M. Macsata, Executive Director of the Association for Airline Passenger Rights. He said that his organization is planning a "major campaign" against TSA's "one-size-fits-all" approach.
Body scanners were first introduced in 2010 following the failed Christmas Day 2009 bombing attempt on a Northwest Airlines flight headed for Detroit.