Washington (CNN) - Time is running out for millions of Americans who still haven't gotten stimulus checks -- and they're likely the people most in need.
The Internal Revenue Service is racing to reach these last recipients before a 2 p.m. Saturday deadline, sending out nine million letters in September to people that may have potentially missed out on the $1,200 payments authorized by Congress earlier this year.
While most eligible Americans received the money automatically during the spring and summer, very low-income people who don't normally file tax returns have to register online so the Internal Revenue Service knows how to reach them.
Roughly 12 million people fell into this category and it's unclear how many of them still haven't received their money. More than eight million people had registered online through October, but the Internal Revenue Service declined to say how many payments have gone out to non-filers or how many more have registered since it ramped up outreach.