Application activity for the state’s health insurance exchange has skyrocketed this week, with close to 1,000 people signing up for coverage each day.

That compares to a previous peak of 3,544 enrollees for the entire week before Thanksgiving.

“The surge is now,” said Peter Van Loon, chief operating officer for the exchange, known as Access Health CT. He noted that the exchange’s call center has been getting an average of 2,400 calls per day this week.

As of Wednesday, 22,904 people had signed up for coverage through Access Health’s individual market since it opened Oct. 1, and 100 small employers with 536 workers had applied. Enrollment in Access Health includes people buying insurance sold by private carriers, who represent 60 percent of customers so far, and those enrolling in Medicaid.

Exchange officials are anticipating a busy month, and hope to have 60,000 to 65,000 members by the end of December. The open enrollment period for exchange insurance runs through March 31, but people who want coverage that takes effect Jan. 1 must sign up by Dec. 23.

Of the 60 percent of enrollees signed up for private insurance, 41 percent are over age 55, while 26 percent are under age 35. Van Loon said exchange officials hope the proportion of young people will increase. The age distribution is considered important because younger members, who generally use fewer medical services, typically balance out the costs of older members. But Access Health CEO Kevin Counihan noted under the health law, that there are federal financial protections for health insurers that enroll an unusually high-cost population or experience losses in their exchange plans.

In the figures it reports, Access Health counts someone as enrolled if he or she has been declared eligible for Medicaid or selected a health plan to buy, even if the person hasn’t yet paid the first month’s premium.

Other enrollment trends have remained similar to those in previous months.

Plans are divided into “metal” tiers based on their premiums and out-of-pocket costs. Twenty-nine percent of the private insurance customers have picked “gold” plans, which have the highest premiums but the lowest deductibles and other cost-sharing. Fourteen percent have chosen bronze plans, which have cheaper premiums but higher out-of-pocket costs when members get care, and 2 percent picked catastrophic plans, which are available to people under 30 and have the lowest premiums but high out-of-pocket costs.

Mid-level silver plans have been the most popular, with 55 percent of the customers. But many of those customers will actually face among the lowest out-of-pocket costs when they get care because their incomes are low enough to qualify for federal subsidies to reduce their deductibles and copayments. Van Loon said 36 percent of the exchange’s private-insurance enrollees qualify for the cost-sharing reductions, which are available to people earning below 250 percent of the poverty level.

The cost-sharing subsidies are in addition to federal subsidies to help people pay premiums if they earn below 400 percent of the poverty level. About 70 percent of the exchange’s private-insurance enrollees are buying plans with subsidies.

Anthem Blue Cross and Blue Shield, the state’s largest insurer, continues to dominate the exchange market, with 62 percent of the customers. Thirty-six percent of the enrollees picked plans offered by ConnectiCare, while HealthyCT, a new nonprofit insurer created by funds made available by the federal health law, has 2 percent of the enrollees.

The vast majority of members have signed up online, defying officials’ expectations.

Before the exchange launched, Counihan projected that 30 percent to 40 percent of the applications would come in on paper, something he tried to discourage, since paper applications take longer to process and require information to be manually entered into the system, making errors more likely.

So far, 2 percent of applications have been submitted on paper. Another 22 percent have come through the call center. The 76 percent of applications submitted online includes those handled through brokers and people designated by Access Health to assist people in signing up.

Exchange officials hope to enroll 100,000 people in coverage — private insurance and Medicaid — for 2014, including 60,000 to 65,000 by the end of this month. Counihan said he thinks the state’s rate of uninsured residents can be reduced from about 9.1 percent to 8.6 percent or 8.8 percent by next month.

Counihan said the goal has been to reduce the number of people without health insurance by a third in the first year. The state has just under 350,000 people without health insurance, so signing up 100,000 people would get close to that goal. But some of the exchange’s customers are likely to be people who currently have insurance but have had their plans discontinued or prefer an exchange plan, so the number of exchange customers won’t necessarily correspond directly to a reduction in the number of uninsured.