The ratio could still change though, with less than two weeks in open enrollment. The most recent HHS data comes from the end of February, and the final weeks of the White House's enrollment push has largely focused on reaching young adult men.
Why is this happening?
Karen Davenport, who heads health policy for the National Women’s Law Center, said she had expected to see more balance in the signups. She offered a couple of reasons for why women are signing up at faster rates, but she stressed they were speculative.
For starters, women have more experience making health care decisions than men do, Davenport said. Secondly, new individual policies now have to cover preventive services and maternity benefits, which were scarcer before the health care law.
“The insurance that’s available is looking pretty attractive to women,” she said.
A study from NerdWallet issued Wednesday suggests that young women indeed could get a good deal from the health care law. For a little less than the same annual cost of preventive services and oral contraception (about $1,231) for a woman without insurance, a 27-year-old woman earning $25,000 could purchase a bronze exchange plan for on average $1,116 per year. The same woman could buy a silver plan, which has lower out-of-pocket costs, for about$1,740 per year.
Before the Affordable Care Act's major insurance market reforms took effect this year, gender rating was allowed - meaning insurers could charge women more than men. A 2012 report from the National Women's Law Center found that gender rating cost women $1 billion more than men, even before maternity costs were taken into account. The law now requires insurers to ignore gender when they price plans, meaning women will get a better deal. It also means that men, particularly young adults who were already purchasing insurance in the individual market, could face higher costs this year.
A Milliman report prepared for America's Health Insurance Plans last year projected that the ACA's new gender rules would drive down premiums between 13 percent and 19 percent for women younger than 40. The actuarial firm also found men in the same age bracket would see premiums go up 18 percent to 31 percent.
Still, the HHS enrollment figures show that men and women in the 18-34 demographic are signing up at the same pace. Twenty-five percent of women selecting health plans in the 36 states with federal-run exchanges are 18 to 34 years old. The rate is 26 percent for men in the same age bracket. Actually, the breakdown is very similar across other age ranges, too.
The disparity in men and women signups is more pronounced in a few southern states. In Louisiana, 60 percent of those signing up for exchange plans are women. The male-female ratio is the worst in Mississippi, where 61 percent of the 25,500 people who signed up for exchange plans are women.
Roy Mitchell, executive director of the Mississippi Health Advocacy Program, said there's been effective anti-Obamacare messaging targeting men in the state, where Obamacare advocates have limited resources for outreach. In the final weeks, advocates are targeting white, male construction workers for enrollment.
"Eighty-five percent of the uninsured are working people and working families," Mitchell said. "A large percentage of that, we recognize, are construction workers."
David Axene, a fellow with the Society of Actuaries, said he's not surprised by the gender enrollment split. Women tend to be more conscious of their health care needs, and Axene said he hasn't seen the individual mandate as much of a motivator for men.
"The people who say, 'I'm healthy and more than willing to pay the mandate because I'm healthy' – I've seen more men saying that than women," he said.
What will this mean for rates?
If women can no longer be charged more and women are signing up at higher rates, does that mean we can expect an increase in insurance rates next year?
We already know that rates are going up in 2015, just like any other year. How much they'll go up depends on a number of factors beyond gender, including how accurately insurers were able to predict their 2014 enrollment mix. Remember, the health law also includes several premium stabilization programs intended to head off massive rate hikes.
Actuaries I talked with had predicted different gender ratios for the 2014 enrollment period. Milliman's Jim O'Connor, who authored the report for AHIP, said he had expected a 52:48 female-to-male ratio in 2014. He said it's not clear how that will factor into 2015 rates.
"It's hard to say what [insurers] will think," O'Connor said. "The expectation is if young males sat out in 2014, maybe more of them will come in 2015 – especially when they see they're getting the tax penalty for sitting out."
Axene with the Society of Actuaries said he had expected the split to be even higher, with women making up 60 percent of enrollees in 2014. With less than two weeks to go in enrollment, he said he doesn't expect the current 55-45 split to change much.