Nearly 100,000 South Carolinians enrolled in a health insurance policy on between Oct. 1 and March 31, the director of the state's insurance department said Monday.

But only some of those 97,387 individuals - about 57 percent - have paid their first month's premium, Director Ray Farmer said.

The number of people actually enrolled may go up or down through May 1 - the deadline by which that first payment must be made.

Data released Monday by the S.C. Department of Insurance shows a sharp increase in Obamacare enrollment in South Carolina during the second half of March. Approximately 30,000 people in this state signed up for a plan during the last two weeks of open enrollment.

"There was a big push between March 15 and March 31 for people to pay attention and sign up and they did," Farmer said.

The average age for South Carolina consumers who selected a plan was 44, Farmer said, and 89 percent of the shoppers qualified for a federal subsidy to lower the costs of their insurance.

The federal government estimates 7.1 million Americans enrolled in an Affordable Care Act policy between Oct. 1 and March 31. It has not released state-specific enrollment reports yet.

Open enrollment for health insurance ended March 31 and will not reopen for 2015 plans until Nov. 15. The Obama administration extended the deadline through mid-April for some customers who started the enrollment process but encountered problems signing up.

"Those folks can still go on and access assistance through the phone, online or in person," said Shelli Quenga, programs director for the nonprofit Palmetto Project, which has helped Lowcountry residents enroll in health insurance plans.

Farmer said his department has not yet determined how many of the 97,387 enrollees are newly insured, because some of those customers may have simply switched from one insurance plan to another.

In 2011, the U.S. Census estimated more than 700,000 residents in this state had no health insurance.

Nationally, a new Gallup poll published Monday suggested the Affordable Care Act has helped reduce the number of uninsured adults. The percentage of adults in the U.S. who were uninsured during the first quarter of 2014 was 15.6 percent, compared to 17.1 percent during the last quarter of 2013.

Reach Lauren Sausser at 937-5598.