To counter such sentiment, the Obama administration had repeatedly noted that more than 80 percent of ACA customers qualify for financial aid to help pay for their monthly premiums, and that more than half get additional aid to offset out-of-pocket expenses.
And federal officials have pointed out that more than 7 in 10 returning customers this year will be able to buy a plan that would cost less than $75 per month in premiums.
The administration earlier this week revealed that HealthCare.gov, the federal insurance marketplace, through mid-December had seen 8.2 million people in 38 states select plans for 2016, a marked increase over the 6 million plan selections at the same time last year. That doesn't include sign-ups on state-run exchanges, where interest is likely to be just as high as on HealthCare.gov.
The surge of sign-ups could mean that federal officials will easily beat their target of having 10 million paying Obamacare customers as of the end of 2016.
"Millions of Americans will start 2016 with the quality and affordable health coverage they want and need to keep their families healthy and financially secure," Health and Human Services Secretary Sylvia Burwell said Tuesday.
But not even the biggest ACA booster expects enrollment will hit the 21 million predicted by the Congressional Budget Office for 2016.
The Urban Institute/Robert Wood Johnson Foundation report concludes by noting that making several changes to the ACA could "improve the affordability of marketplace coverage," and in turn boost enrollment.
One suggestion the report makes is to link the premium subsidies that most Obamacare customers get to the price of "gold" plans, instead of to the price of the less expensive "silver" plans. Obamacare plans are designated by metal tiers — platinum, gold, silver and bronze. Platinum plans cost the most in terms of premium, but cover the biggest share of health costs. The others cost less, but cover fewer health costs.
The report also suggests that low-income customers could get higher amounts of assistance paying their out-of-pocket costs.
A third suggestion is to put a cap on the percentage of income that people who earn more than four times the poverty level would have to pay for Obamacare plans.
"It's not a great deal of money" to fund those suggestions relative to other federal spending, Holahan said. But it would be difficult to get Congress to appropriate more spending on Obamacare given the current political climate, he said.