PORTLAND — A Maine nurses group on Monday said President Barack Obama’s signature healthcare law, which is criticized by conservatives as overreaching, doesn’t go far enough toward universal health coverage.

The Maine State Nurses Association held Monday afternoon health screenings and an evening “town hall” event at the First Parish Church on Congress Street in Portland to advocate for the expansion of the federal Medicare program to cover all Americans, regardless of age.

The organization is planning to hold a second wave of screenings and another town hall event Tuesday afternoon and evening at the Bangor Public Library.

Currently, Medicare covers Americans age 65 or older, as well as some younger people with certain disabilities. Medicaid, which is a program run jointly by state and federal governments, provides health insurance coverage for qualifying low-income individuals.

But those safety nets miss thousands of Mainers who don’t qualify for government help and can’t afford health insurance, said advocates at the Monday event.

The president’s Affordable Care Act, which requires most Americans to buy health care plans in an effort to use market forces to drive down insurance prices for those least able to afford them, is a step in the right direction, but too complicated, Dr. Philip Caper said Monday.

Caper is a founding board member of the organization Maine AllCare and a Bangor Daily News columnist.

“Even under the best of circumstances, ‘Obamacare’ will leave 30 million people uninsured,” he said. “I think Obamacare is a step in the right direction … but I don’t think it does the job. The financing should be public, just as we finance our roads and our libraries and our judiciary.”

Liz Faraci, a nurse with Downeast Community Hospital in Machias, helped with the Portland screenings Monday. She said a universal, single-payer system in America would ensure that hospitals are reimbursed for all care given because all patients would be insured by the federal government.

Caper said his organization is pushing for Maine to adopt a universal health coverage plan before the federal government does. He said U.S. doctors carry four times the administrative staff as their counterparts in Canada, where the universal health coverage is offered, because of the complications of dealing with insurance companies and piecemeal government programs in place today.

“In all other wealthy countries, when people get sick, they don’t worry about how to pay for it,” he said. “Healthcare costs are the largest single cause of personal bankruptcy in our country.”