Bare-bones health insurance could cost just $11 a month for a family of four in Indianapolis on the federal government's new exchanges, which start serving customers next week.
A similar family in New Orleans might pay as little as $23 a month, although they'd have to shell out $282 for a more generous "silver" plan, the Health and Human Services Department estimates.
And, on average, people will have more than 50 different health plans to choose from if they live in states where the federal government is running the exchanges, HHS says in a report issued Wednesday.
(Read more: Questions about Obamacare you were afraid to ask)
HHS has analyzed the plans that have been approved to go on offer starting Tuesday and finds that in most states, there's plenty of choice with reasonable prices. That gives the administration ammunition against critics who have been warning that health insurance will cost more in the exchanges than it does now.
"In many cases, premiums will cost significantly less than what was originally projected," Health and Human Services Secretary Kathleen Sebelius told reporters on a conference call. The report finds that 95 percent of Americans live in states where the premiums for individually purchased health insurance will be less than what had originally been expected.
The health insurance exchanges are one of the supporting pillars of the health reforms called for under the 2010 Affordable Care Act. The law, widely known as Obamacare, is meant to get more Americans covered by health insurance so they'll take better care of their health.
More from NBC News:
The administration has been fighting a pitched battle against Republicans who oppose the health reforms, and who have been making a show of the law down in Congress -- although they are unlikely to win out against a Democratic-controlled Senate and President Obama.
Most Americans -- about 55 percent, or 157 million people -- get health insurance through an employer, and 30 percent more get Medicare, Medicaid or some other government insurance, with just a few buying their own insurance privately. The U.S. Census Bureau says 15 percent of Americans don't have insurance at all.