ALBANY -- Gov. David Paterson says New York is joining several other states suing the federal government over a new federal Medicaid rule.

Paterson says the new Centers for Medicare and Medicaid Services rule will sharply limit New York's ability to provide case management to vulnerable populations throughout the state.

The new rule revises existing regulations and could eliminate federal funding currently available for certain services. It would require states to make costly changes in their billing and reimbursement systems.

Maine, Maryland, Oklahoma and New Jersey are the original states to sue. The lawsuit was filed weeks ago in federal court in Washington, D.C. Since then, Kentucky and Tennessee have also joined the suit.