NEW YORK, Sept 10 (Reuters) - One in seven Americans

have signed up for health insurance coverage through Affordable

Care Act marketplaces since their 2014 launch, according to data

released on Tuesday by the U.S. Department of the Treasury.

A total of 49.4 million Americans have signed up for the

plans, often referred to as Obamacare, with enrollment reaching

a high of 20.8 million people in 2024, the agency said.

The insurance plans, run by companies including CVS Health's ( CVS )

Aetna and UnitedHealth Group ( UNH ), provide

income-based subsidies and are sold on the federally-run

Healthcare.gov website or are offered directly by states that

run their own sites.

Marketplace coverage since 2014 has been higher in states

that have not expanded Medicaid programs under the ACA or did so

later, the report said.

Typically, people with annual incomes between 100% and 138%

of the poverty level - currently set by the government at

$15,060 for individuals and $31,200 for a family of four - are

covered by the ACA Marketplace in non-expansion states, versus

Medicaid in expansion states.

Florida, Utah and Georgia, for instance, topped marketplace

enrollment by percent of population with an average of 20% of

residents, compared with 12% of residents in states that

expanded Medicaid coverage. Data cited in the release was

collected by the Internal Revenue Service from tax forms and

other sources.

The average cost of premiums for a year of enrollment in a

marketplace health plan fell to $800 through the Biden

administration's four years, a senior administration official

said.

"Marketplace enrollment has surged under the

(Biden)Administration, which has especially helped American

families with their monthly bills and entrepreneurs who are

looking for coverage as they start new businesses," said U.S.

Secretary of the Treasury Janet Yellen in a statement released

on Tuesday.