Most people who got tax credits to buy insurance under the federal health law will be repaying part of them for the second year in a row, according to a leading tax preparer.

H&R Block Inc. executives said Tuesday that, to date, 60% of 2015 tax filers with the credit have found that they owe the government money because they had been credited too much. That is up from 52% last year, the first year in which filers had to reckon with reporting the credit and figuring out if their income projections had been accurate.

On average, tax filers were repaying almost $580 each for excessive credits, up from $530 for overpayments during the 2014 filing year.