The government could improve Medicare oversight by creating a more uniform and unified post-payment review system, according to a report from federal officials.

The Government Accountability Office reviewed how thoroughly the Centers for Medicare & Medicaid Services implemented past recommendations for preventing and recouping improper payments. CMS has “made progress” but “further action is needed,” according to the report released Tuesday.

For example, CMS has implemented a predictive analytics program to detect potentially “aberrant” Medicare claims. The GAO previously recommended that this system be synced with the payment-processing system, so that payments for flagged claims are withheld until Zone Program Integrity Contractors can investigate. In April 2014, CMS reported that it had integrated the system; however, it still cannot stop payments of suspicious claims, according to the GAO.

CMS also has not yet narrowed differences in how its four different types of contractors carry out reviews, the report states. Doing so — for example, by creating a uniform guideline for how quickly providers have to comply with an additional documentation request — could improve efficiency and effectiveness, according to the GAO.

CMS also could take steps to improve prepayment reviews, such as by disseminating information about various contractors’ best practices, the report states.

GAO emphasized it will continue to investigate Medicare program integrity efforts, including the provider appeals process that has led to a huge backlog. Concerned Congressional lawmakers pressed a GAO official and other witnesses on this issue at a hearing earlier this week. Yesterday, the American Hospital Association filed a lawsuit in the matter.