Congress, anxious to keep down the program's soaring cost, decided the states should pay 90 percent of the expense for senior citizens who qualify for both Medicaid and Medicare, Stateline.org reports.
"What had been expected to bring relief to state budgets has instead turned out to be an unmanageable and uncontrollable cost to state budgets," said Diane Rowland, executive director of the Kaiser Commission on Medicaid and the Uninsured.
Kentucky has already announced plans to sue over the "clawback" and Gov. Rick Perry of Texas urges his counterparts simply not to pay.
To add insult to injury, Stateline says that among the states likely to be hurt the worst are those that have done a good job of bringing down drug costs. That's because the state reimbursements are based on 2003 expenditures, a time when drug prices were at their peak.