Drat. I was off by 0.3% this time...

ACA Signups February Enrollment Projection, 3:48pm today:

#ACASignups With #NY update, new Feb. projection is 870K QHPs for 4.17M total by 3/1 http://t.co/MYSDQWQTVC @LOLGOP @Eclectablog

— Charles Gaba (@charles_gaba) February 25, 2014

• February 2 - February 24 = 23 days
• 23 days / 28 days) = 82.1%
• 82.1% x 870,000 = 714,270 enrollments from 2/02 - 2/24

714,270 + 3,299,492 = 4,013,762

The Huffington Post, 5:59pm:

WASHINGTON -- Approximately 4 million individuals how now signed up for health care plans under the newly created Obamacare insurance exchanges, a senior administration official told The Huffington Post on Tuesday.

UPDATE: Confirmation from the official HHS Dept. blog:

As we head into the last five weeks of this historic open enrollment period, millions of Americans are taking advantage of the new choices they now have to access affordable, quality health care thanks to the Affordable Care Act.  The most recent data indicate that approximately 4 million people have now signed up for a private health insurance plan through the Federal and State-based Marketplaces since October 1.  A full enrollment report for February will be released in mid-March.