NEW YORK (Reuters) - Enrollment in 2016 individual insurance through the HealthCare.gov website is higher than it was a year ago at this time, with 1 million new customers signed up, U.S. government health officials said on Wednesday.

The officials cited the latest enrollment data as a reason for confidence in the long-term stability of HealthCare.gov, which was created under President Barack Obama's national healthcare law and sells individual insurance plans in 37 states.

Private insurers including Anthem Inc, Aetna Inc and UnitedHealth Group Inc are among private insurers selling plans on HealthCare.gov, and who have said they are losing money on the business.

A top health official said during a conference call with reporters that the market is robust, with more than 100 insurers selling plans there.

"I would caution you not to be overly swayed by any one or a handful of companies and whether they are making money or not," said Andy Slavitt, acting administrator of the Centers for Medicare and Medicaid Services division of the U.S. Department of Health and Human Services.

More than 9 million people have insurance purchased through the government exchanges, with many of them receiving subsidies aimed at making monthly premiums more affordable. By the end of 2016, the government estimates about 10 million people will have this type of insurance, which was first sold in 2014. That number is far short of the 20 million that had been forecast by the Congressional Budget Office for 2016.

In addition to the 1 million people who have signed up since enrollment opened on Nov. 1, about 1.8 million customers have renewed their plans. Enrollment closes on Dec. 15 for coverage effective Jan. 1 and on Jan. 31 for 2016 coverage.

The government said earlier this week that the special enrollment period that had been open around the income tax deadline would not be available this year.

UnitedHealth said last month that it would reconsider the extent of its role on the exchanges, through which it now sells plans in about two dozen states. The company said that patients, particularly those who were signing up during special enrollment periods, had higher medical costs than expected and that it had lost money. Insurers also said that the cut in 2016 enrollment expectations would hurt profits.