One of the key provisions of health reform — coverage of pre-existing conditions—takes effect today.

But many states, including New York, are not ready yet to accept applications, and it may be at least several months before qualified applicants can apply for assistance.

The Patient Protection and Affordable Care Act, which President Obama signed into law in March, created a national high-risk insurance pool to pay for temporary health coverage to people with pre-existing medical conditions who have been uninsured for six months.

The program will continue until Jan. 1, 2014, when the reform law requires health insurance companies to cover adults regardless of pre-existing conditions.

A pre-existing condition is a medical condition — such as diabetes, heart disease or mental illness—that existed before someone applies for health insurance. Insurance companies often reject such individuals, charge them high premiums or refuse to cover treatment for the condition until 12 months or 18 months have elapsed.

“We’re hoping to have a program up and running in a couple of months, and our goal is to have it priced lower than what an individual would have to pay for coverage on the open market,” said David Neustadt, spokesman for the state Insurance Department.

In April, Gov. David A. Paterson announced that New York would design its own program, a decision that opened the way for the state to receive $297 million to fund a high-risk pool. Neustadt said the Insurance Department is still designing the program, and a proposal must then be

submitted to federal officials for review.

Congress allocated the program $5 billion, but there are concerns over funding. The Congressional Budget Office estimated that money may be exhausted before 2013 if more than 200,000 people sign up.

The high-risk pools are supposed to cover at least 65 percent of enrollees’ health care costs. At that level of support, the CBO estimated that enrollment could grow to 700,000 nationwide by 2013 and cost $10 billion to $15 billion.

About 35 states already operate high-risk pools for uninsured individuals, according to the National Conference of State Legislatures. The health reform law allows all the states to operate the new pool alongside their existing programs, establish new pools for the temporary federal program or have the federal government create a program.

Most states have opted to operate their own high-risk pools.

Some states, such as New York, require insurers to sell health insurance policies to anyone who applies, although the policies can include clauses that deny coverage of pre-existing conditions for a period of time.

“It’s hard to say how all this will play out here. With guaranteed issue, there are people with insurance who would have to give it up to get into the temporary high-risk pool,” Neustadt said.

One other unknown factor is how much the high-risk pool insurance policies will cost in each state.

There is little doubt that many patients with ailments could use some help.

For instance, a new poll conducted for the American Cancer Society Cancer Action Network found that one in three families under age 65 affected by cancer are having trouble affording nonmedical bills, such as for food and housing.

“We’re hoping the new high-risk pools will help by offering coverage at a rate that isn’t confiscatory,” said Peter Slocum, vice president of advocacy for the society’s eastern division.