UnitedHealthcare will not offer any health plans on Georgia’s insurance exchange in 2017, state officials say.

The giant Minnesota-based health insurer also said this week that it will pull out of Arkansas’ exchange for next year.

The insurer, whose parent company is UnitedHealth Group, could not be immediately reached for comment Friday afternoon.

UnitedHealthcare is the only company so far that has informed Georgia’s insurance department that it won’t be participating in the exchange next year, Glenn Allen, a department spokesman, said Friday.

The company is one of nine offering plans in Georgia’s exchange this year. Under the Affordable Care Act (ACA), all states have exchanges — most of which are federally run — that help consumers find and buy health coverage.

May 11 is the federal deadline for insurers to inform the government of their exchange plans for 2017.

Despite United’s decision to pull out of the Georgia exchange next year, Allen said Harken Health, an independent subsidiary of United, will be a participant.

United, citing financial losses, had warned weeks ago that it might pull out of the exchanges.

It said in January that it had lost $720 million nationally on its individual-market health plans in 2015, the first year the company participated in health insurance exchanges.

The insurer said the losses stemmed from sicker-than-average consumers enrolling in its health plans and a surplus of people signing up beyond the regular enrollment period. The insurer ended last year with about 500,000 enrollees in exchange plans.

Other insurers also have criticized exchange enrollment rules for people who sign up outside the annual “enrollment window” — in other words, beyond the sign-up deadline.

The ACA allows customers to buy coverage outside the standard time frame if they lose a job, get divorced or have a child, among other reasons. But insurers want the federal government to take a closer look at such people, to find out whether some of them truly qualify for exemption from the time rules.

The law established an enrollment window, officially known as an open enrollment period, to prevent people from simply waiting until they became sick before they bought insurance. But insurers say it has become too easy for customers to sign up past the proper deadline.

The federal Centers for Medicare and Medicaid Services recently outlined several changes it said it was making to help shore up exchange enrollment windows.

Bill Custer, a health insurance expert at Georgia State University, said Friday that United “obviously is making a business decision on where to put their resources.”

The company and other insurers feel that the enrollment rules are “too easy to game the system,” he said.

Health insurance markets in general — and the exchanges specifically — are in flux, Custer said. “The model is changing for all insurers.”

United’s pullout is a blow to the Georgia exchange, he said. “Any time consumers lose choice in the exchange, it’s a setback.’’

But he said it’s difficult to believe that United, the nation’s largest health insurer, will remain out of the exchange market forever. “The ACA has created a market that insurers will have to adapt to,’’ he said.

Georgians may also lose other insurance exchange options if the pending mergers of Aetna and Humana, and Anthem and Cigna, are approved by regulators.

More than 580,000 Georgians signed up for coverage in the insurance exchange for this year.

The total of 587,845 during the sign-up period, which ended Jan. 31, was a 9 percent increase over last year’s Georgia total of 536,929 at the end of open enrollment.

Georgia’s enrollment total trailed that of Florida, Texas and North Carolina among states using the federally run exchange.