TALLAHASSEE -- As lawmakers decide how — or whether — to move forward with parts of the federal Affordable Care Act, House and Senate select committees plunged Monday into issues such as a potential expansion of the Medicaid program and the law’s effects on Florida businesses.

In back-to-back meetings, lawmakers heard testimony from people with far-different perspectives about the controversial health overhaul, which Florida Republican leaders resisted for more than two years.

Backers, including two physicians, urged the committees to carry out important parts of the law, including expanding Medicaid eligibility to hundreds of thousands of additional people. Trying to put a face on the state’s uninsured population, Palm Beach Gardens resident Arie Strobel told lawmakers that she and her daughter have been unable to get coverage since her husband died suddenly in 2009, creating worries and causing her to forgo doctors’ visits.

"There’s that fear in the middle of the night, what am I going to do when I have something or when she has something? How are we going to handle this? And I kind of just close my eyes,’’ Strobel, 53, said.

But the Senate select committee also heard concerns from employers about how coverage requirements and penalties in the law could drive up costs for businesses. The concerns center, at least in part, on small businesses that have struggled in recent years with increasing health-insurance premiums.

"I’ve got to tell you that I’m thoroughly confused,’’ said Kim Williams, president of Marpan Supply Co., a Tallahassee recycling business that has 74 employees. "I don’t know what it’s going to cost me next year."

The meetings came as lawmakers prepare to make decisions during the upcoming legislative session about a series of major issues stemming from the law, better known as Obamacare. Unlike a boisterous Senate meeting last month that drew tea-party activists and other Obamacare opponents, Monday’s discussions were relatively low key.

It appears clear, however, that lawmakers are focusing on a few big Obamacare-related issues heading into the session, which starts in March. They include whether to expand Medicaid eligibility, whether to take part in operating a health-insurance exchange and how to deal with changes in insurance regulations.

Gov. Rick Scott, a longtime critic of the health law, became embroiled in a controversy last week after he repeatedly said expanding Medicaid eligibility would cost the state an estimated $26 billion over 10 years. After it became public that state budget analysts had questioned the validity of that estimate, the Agency for Health Care Administration revised it to as low as $3 billion.

Sen. Joe Negron, a Stuart Republican who chairs the Senate select committee, said the range of estimates is too "expansive" and that it needs to be narrowed. He said the state will work to have the best estimates it can.

"We’re never going to have a perfect number,’’ said Negron, who also is chairman of the Senate Appropriations Committee.

During a presentation about various elements of Obamacare, House staff director Christa Calamas said part of the complexity of the law is that it depends on hard-to-predict human behavior.

"It’s very difficult to anticipate what the effects will be,’’ Calamas said at one point.