In recent years, the department has been using the False Claims Act to more aggressively go after hospitals, doctors and other health care providers that are over-billing or providing unnecessary medical services.
Hospitals have responded by saying they have been unfairly targeted by an overzealous agency. That prompted the Justice Department to issue guidance to its offices on the proper use of the law.
In a report released Tuesday, the GAO, Congress' investigative arm, reported that work groups in the department "have made further progress" in issuing guidance around four national initiatives; each targets a specific type of payment, such as those to laboratories.
However, GAO said, the process for assessing progress on the guidelines "may be superficial," because it simply involves reviewers asking supervisors what they have done.
"We are recommending that [the department] take additional steps to improve its oversight of national health care initiatives," the report said.
GAO also found the implementation of guidelines varied across the country. In some offices, the report said, officials were not acting in accordance with the rules. In several offices, government attorneys were sending hospital labs threatening letters even though they did not yet have evidence of wrongdoing.
Still, GAO reported that hospital concerns about use of the False Claims Act had diminished since establishment of the guidelines.