With so much riding on the success of the Affordable Care Act, officials in the Obama administration felt it necessary to inflate the number of Americans who had signed up for health insurance.

They tried pulling off this statistical sleight of hand by combining the number of people who had purchased dental coverage on the healthcare exchanges with those buying health insurance.

Somehow, the officials didn’t think anyone would notice … despite the fact they had previously reported the dental and medical totals separately.

In May, the Center for Medicare and Medicaid Services (CMS) reported that 8 million individuals had bought medical coverage and about 1.1 million had signed up for dental insurance. Then in September, CMS reported that 7.3 million people had purchased insurance through Obamacare without specifying that the total included both medical and dental purchases.

A breakout of the data showed about 7 million had bought health coverage and 380,000 dental coverage.

The Department of Health and Human Services (HHS), which oversees CMS, had to backtrack and admit that officials “erroneously” folded sign-ups for the two different plans together. “A mistake was made,” a spokesperson for HHS said in a statement, adding that, in fact, 6.7 million Americans had purchased medical coverage as of October 15.

CMS chief Marilyn Tavenner will have the opportunity to explain when she testifies before the House Oversight Committee on December 9.

-Noel Brinkerhoff

To Learn More:

What ACA Enrollment Numbers Tell Us – and What They Don’t (by Joanne Kenen, Association of Health Care Journalists)

Administration Inflated Obamacare Enrollment Numbers (by Tara Culp-Ressler, ThinkProgress)