Administrative law judges had a 936% increase in Medicare claims between fiscal years 2010 and 2014, a new government report finds.

Despite attempts from government agencies to address the growing number of Medicare appeals, the backlog “will likely persist,” according to a Government Accountability Office report, released Thursday.

The Medicare claims appeals process has four administrative review levels within the Department of Health and Human Services, and a fifth level where appeals are reviewed by federal courts. While Level 3 is administrative law judges, the appeals filed at the other levels also grew significantly, the report said. The total number of claims appealed to the Office of Medicare Hearings and Appeals has grown 1,000% over the last six years.

Factors include a renewed focus by the Centers for Medicare & Medicaid Services to expand program integrity and crack down on improper payments. As more claims are denied through enforcement, more providers file appeals.

The GAO report acknowledges that federal agencies have taken “several actions” to reduce the total number of appeals filed and cut down on the backlog. One such action is a move made by CMS in 2014 to pay a portion of some denied hospital claims with the condition that any pending appeal associated with those claims is withdrawn. The FY 2017 President’s Budget also includes legislation to create a refundable claim filing fee that HHS would use to “improve responsiveness and efficiency” of the appeals process.

Officials have tried to address the backlog through court orders, legislation and additional funding in a recently approved Senate appropriations bill.

The GAO recommends HHS create a more efficient way of handling appeals linked to “repetitious” claims, and improve the “completeness and consistency” of the data it uses to monitor appeals.

Click here to read the full GAO report on improving the Medicare fee-for-service appeals process.