Medicaid supplemental payments exist outside the fee-for-service and managed-care models.
The GAO report dealt with one type — non-disproportionate-share-hospital (DSH) payments — which are funded jointly by the states and the federal government and may go to a variety of healthcare providers in Medicaid.
Auditors with the GAO contrasted oversight of non-DSH payments, which they found lacking, with the government's fuller understanding of DSH payments, which reimburse some hospitals for uncompensated costs related to serving a large population of low-income or Medicaid patients.
"Without information on allocations of non-DSH payments to individual providers, [the Medicare-Medicaid agency] and others are unable to identify or assess total Medicaid funding received by individual providers and how Medicaid payments relate to providers' Medicaid costs," the GAO wrote.
Hatch said the lack of information on non-DSH payments allows taxpayer dalliers to "fall by the wayside."
"It’s past time we act to restore the fiscal integrity of the Medicaid program and work to create aggressive oversight policies that will guarantee the transparency and accountability American taxpayers deserve," he said in a statement.