(Source: Avalere Health)
(Source: Avalere Health)

After yesterday's announcement on Obamacare enrollment numbers, the Avalere Health consulting firm this morning projects that 5.4 million people will sign up in exchange plans by the end of open enrollment on March 31. The analysis, based on the enrollment experience in the Medicare prescription drug program, puts enrollment about 600,000 behind the 6 million people the Congressional Budget Office projected.

About 4.2 million had signed up for exchange plans through the end of February. Avalere thinks the administration will bring in 1.2 million more people this month after 940,000 had signed up in February.

A couple of things about the Avalere analysis: It's based on signups and not official enrollment. News reports and insurers have said about 80 percent of those signing up for exchange plans have paid their first month's premium. So, the final enrollment numbers could be smaller. Also, the top-line number doesn't say much about who's actually enrolling.

The administration has downplayed the importance of how many people actually sign up. It's much more important, officials say, that each state have a good mix of healthy enrollees in their individual markets.

On the eve of the Obamacare launch, Health and Human Services Secretary Kathleen Sebelius said success would be 7 million people signed up in exchange plans by the end of March. So, what does the Obama administration now say will be a success in the program's first year? Sebelius was asked that question again this morning during her testimony to the House Ways and Means Committee.

"Success looks like millions of people with affordable health coverage, which will have by the end of March," she said.