An advocacy group for public hospitals plans to lobby its members to continue explaining to state leaders the importance of Medicaid expansion under the federal healthcare reform law.

HHS clarified in a letter issued Monday that it will cover all costs of expanding Medicaid enrollment, as authorized by the Patient Protection and Affordable Care Act, only in states that undertake an expansion of Medicaid eligibility to 133% of the federal poverty level, or as high as 138% of the federal poverty level. Some state political leaders had asked whether they could partially expand eligibility and still receive the federal funding.

The National Association of Public Hospitals and Health Systems, representing many of the safety net hospitals facing some of the biggest effects of state decisions on Medicaid expansion, will urge its members to take up the cause of expansion in their states, said Beth Feldpush, the association's vice president for advocacy and policy.

"It's a little too early to see how it plays out, but I think states will definitely be considering that cost question as they make their decisions," said Feldpush.

At least one member of Congress said Tuesday that he doubted state officials ultimately will refuse to expand their programs.

"My guess is that in a lot of these states that have walked away from expanding Medicaid, their people are going to discover that they are being cut off of very basic stuff, and then they are going to get very angry and then those governors are going to come running back," Sen. Jay Rockefeller (D-W.Va.) said during a news conference.