If you haven't filed your taxes yet, experts suggest you get it done this week.
It's all because of the possibility of another government shutdown.
But officials say there is already confusion around about the new tax forms, including the 1040. There are no personal exemptions, but the standard deduction is more generous.
"It is now postcard size," said Darla Mercado, CNBC personal finance writer. "But what you need to be aware of there are now six schedules that you need to complete and file that return."
The IRS expects 90 percent of all of returns to be filed electronically this year.