McKinsey surveyed 1,300 employers to gauge the effect the Affordable Care Act (ACA) might have on benefits -- 30% said they will "definitely" or "probably" stop offering employer-sponsored insurance after most of the major provisions of the act go into effect in 2014.
Between 45% and 50% of employers said they will "definitely" or "probably" pursue an alternative to employer-sponsored insurance, which could also include asking employees to contribute more to their coverage or offering coverage only to certain employees.
The findings differed drastically from those of the nonpartisan Congressional Budget Office, which projected that about nine or 10 million people, or about 7% of employees who are currently covered by employer-sponsored plans, would have to switch to a plan offered in the health insurance exchanges.
Senate Finance Committee Chairman Max Baucus and nine House Democrats want to know why the difference.
On Thursday they sent letters to McKinsey calling on the company to release the methodology of the survey; what specific questions were asked; how they were asked; who funded the survey; and whether McKinsey stands to gain financially from the survey.
In a letter to McKinsey managing director Dominic Barton, Baucus pointed out that the decision to stop providing employee health insurance "is a major business decision that will be made by more than one person" and asked how the survey accounted for that.
The findings are "so markedly out of sync with other assessments that it has raised legitimate questions about the product, including how and why it was created," wrote the House Democrats, which included Rep. Henry Waxman of California and Rep. John Dingell of Michigan.
"Honest public discourse requires a standard level of transparency -- one McKinsey simply has not met," said Baucus in a press release. "The conclusions
McKinsey reached differ sharply from results of other reputable, transparent research on the subject ... We all want the most accurate information and the ability to evaluate its integrity, which is why McKinsey should answer these basic questions."