South Carolina leaders may or may not choose to expand Medicaid eligibility to more low-income residents — it seems like they’re leading toward not — but one thing’s for sure: In 2014, the federal government will help pay for health insurance for hundreds of thousands of residents here.

A new study commissioned by an advocacy group shows that 418,000 South Carolinians who make 100 percent to 400 percent of the federal poverty level will qualify for some level of federal tax credit to help lower the cost of health insurance under the Patient Protection and Affordable Care Act.

For a single adult, 400 percent of the federal poverty level is approximately $46,000 in annual income. For a family of four, 400 percent of the federal poverty level is about $94,200, said Ron Pollack, executive director of Families USA, the health care group that commissioned the study.

The tax credits will be available to qualified residents throughout the country who shop for a health insurance plan through a state or federal health insurance exchange. The credits are intended to help lower-to-middle-income Americans pay for health insurance.

A separate part of the federal health care law will expand Medicaid to individuals who make up to 138 percent of the federal poverty level. States can choose to opt out of that expansion though, because each state will eventually be required to pay for 10 percent of the Medicaid expansion costs by 2020.

Many conservative state leaders in South Carolina, including Gov. Nikki Haley and Medicaid Director Tony Keck, are opposed to expanding Medicaid. They say the program is already too expensive and isn’t improving health outcomes.

Keck said the Families USA projection is close to the projection by the state, which estimates 433,000 individuals will qualify for the tax credit.

“It is confirmation of our argument that hundreds of millions of new profits from federal subsidies will pour into South Carolina hospitals each year even without Medicaid expansion,” Keck said.

Last month, the state House voted against expanding Medicaid. The Senate could take up the issue before the General Assembly session ends in June.

Families USA is a pro-Medicaid expansion group.

“My own view is that it’s a no brainer,” Pollack told reporters in a press call on Wednesday.

The Families USA study found that 89 percent of individuals qualifying for the tax credit in South Carolina will be part of working families and “young adults are the likeliest age group to be eligible for premium tax credits, making up approximately 34 percent of all those who will be eligible.”