The Affordable Care Act requires those who didn’t have insurance last year and didn’t qualify for one of the exemptions to pay a tax penalty, which was widely cited as $95 the first year. But the $95 is actually a minimum, and middle- and upper-income families will actually end up paying 1 percent of their household income as their penalty.

TurboTax, an online tax service, estimated that the average penalty for lacking health insurance in 2014 will be $301.

“People would hear the $95, quit listening, and make an assumption that that was what their penalty was going to be,” said Chuck Lovelace, vice president of affordable care for Liberty Tax Service. “I think that a lot of people will be surprised when they get in there and find out that their penalty is [based] on their household income.”

The penalty is designed to prod Americans to buy insurance and the penalty for not having it is scheduled to rise considerably: to a $325 minimum or 2 percent of income in 2015, and to a $695 minimum or 2.5 percent of income in 2016.