About 6.6 million U.S. taxpayers paid a penalty, imposed for the first time this year, for not having health insurance. That’s about 10 percent more than the Obama administration had estimated — although a portion didn’t need to,Bloomberg reported.

The penalty of as much as 1 percent of income was implemented under the Patient Protection and Affordable Care Act, and was meant to encourage people to sign up for health insurance. The Treasury Department had estimated in January that as many as 6 million taxpayers would pay the fine.

The average penalty was $190, the Internal Revenue Service said Wednesday in a report, which also detailed abysmally poor customer service by the IRS,USA Today reported. About 300,000 taxpayers overpaid the penalty, with overpayments totaling about $35 million. Most should have been exempt for their low income, according to the agency. The average overpayment was a little more than $110. The IRS hasn’t decided yet whether to issue a refund for the overpayments.