The delays impact 40 million working poor families claiming the earned income tax credit and the additional child tax credit.
For 2016, the maximum earned income tax credit is from $506 for no qualifying children to $6,269 for three or more qualifying children.
"For most of these people it's the biggest check they are going to get all year," IRS Commissioner John Koskinen told the Associated Press in an interview. "We are sensitive to that."
Under the 2015 PATH Act that goes into effect this year, the IRS must delay these refunds to have more time to screen the returns. Scammers and organized crime syndicates have been filing fraudulent returns and claiming tax payers refunds before they have a chance to file, according to the IRS.
The agency has been reminding taxpayers and prepares about the change in news releases since this summer.
Tax filing starts January 23. The IRS says most direct deposit e-filers usually receive their funds within 21 days. So those filing on day one might see their refund by mid-February. But now the additional processing time will delay those refunds until the end of February, Koskinen said.