From an AP Fact Check story today:
A recent report by House GOP leaders says “independent analyses have determined that the health care law will cause significant job losses for the U.S. economy.”
It cites 650,000 lost jobs as Exhibit A, and the nonpartisan Congressional Budget Office  as the source of the analysis behind that estimate. But the budget office, which referees the costs and consequences of legislation, never produced that number.
What CBO actually said is that the impact of the health care law on supply and demand for labor would be small. Most of the lost jobs would come from people who no longer have to work, or can downshift to less demanding employment, because insurance will be available outside the job.