PROVIDENCE — Faced with potentially dramatic changes to the state’s Medicaid program, but few associated details, doctors and health-care groups say they are increasingly worried about that lack of specifics.

“Nobody knows what the fine tuning looks like and that’s the scary part,” said Pawtucket family physician Dr. Michael Fine.

In a groundbreaking experiment of sorts, the Carcieri administration is attempting to reform its health-care safety net for the poor, the elderly and the disabled, by agreeing to limit all spending on Medicaid programs –– which consume about a quarter of the state budget –– for the next five years in exchange for broader flexibility to modify the state’s health-care system.

While the state has promised far-reaching changes that it says will save $67 million in the current fiscal year, it remains mum on many of the details of that plan, including the size of the five-year spending cap.

Carcieri’s team says the silence is partly intentional –– it doesn’t want to tip its hand before it starts formal negotiations with the federal government.

But that absence of particulars has created a growing list of questions and a sense of unrest in the medical community, which says it is difficult to plan financially when the entire $1.8-billion Medicaid program may turn on its head.

“Many [health-care] organizations have not publicly expressed support or opposition to the proposal because there are so many unanswered questions,” said Edward J. Quinlan, president of the Hospital Association of Rhode Island.

Indeed, some in the health-care community refused yesterday to comment on the waiver application, saying they didn’t yet know enough about it.

Broadly speaking, here’s what is known about the proposed change, as outlined in the 91-page waiver application: it would limit the amount of nursing care in this state, instead encouraging more home-based services; it also would change the eligibility and scope of benefits for Medicaid recipients, possibly eliminating certain services including substance-abuse treatment, dental services and mental-health resources, to help bring benefit packages in line with commercial plans.

Additionally, it could alter subsidized transportation programs for the disabled and the elderly and modify prescription-drug coverage for seniors.

But those possibilities seem to generate more questions than they answer. Among them:

Who will care for elderly Rhode Islanders who are no longer placed in nursing homes?

What will happen if low-income residents cannot keep up with increased RIte Care co-payments?

Will doctors and health centers that accept Medicaid be reimbursed at lower rates?

“The policy detail in support of that number is not as analytical as it could be,” said Quinlan. The state proposes “fiscal targets and cost-savings targets without identifying how to achieve those savings …”

The fate of nursing home-bound Rhode Islanders seems to cause the greatest anxiety. The waiver proposal outlines stricter eligibility standards for those wishing to enter nursing homes, saving money while allowing seniors to stay in their own homes.

But it remains unclear who will step in to lend a hand to those who cannot care for themselves. The waiver application suggests that some patients may be placed on waiting lists if services are not immediately available.

“The patients I have [that go to nursing homes] are patients that really need to be there and need services that couldn’t be provided for in another venue,” said Dr. Nitin Damle, a Wakefield internist and governor of the Rhode Island chapter of the American College of Physicians. They’re usually on multiple medications, can be at risk of falling, and could use the socialization of a nursing facility to avoid depression, Damle said.

“The proposed alternatives of having people receive care in their homes doesn’t exist at present and would have to be geared up,” said Dr. K. Nicholas Tsiongas, president of the Rhode Island Medical Society.

The Carcieri administration has promised enough lead time to allow doctors and nursing homes to prepare.

Some in the health-care community have criticized the state for refusing to provide further details, but Department of Health and Human Services Director Gary Alexander said the state has had open biweekly meetings, inviting doctors, nursing-home staffers and even patients to come and learn more about the proposed changes.

“There are still questions of course, but it’s been a very open process,” Alexander said. “We’ve answered a lot of questions on the waiver and the level of care has been spelled out in detail.”

cneedham@projo.com