Moody's Corporation (NYSE:MCO) downgraded the outlook of the U.S. health care sector from stable to negative on Obamacare concerns. The constant negative news about the implementation woes of the Affordable Care Act is creating a lot of uncertainty in the healthcare insurance markets. Healthcare.gov, the official federal insurance marketplace is still facing technological glitches on the back end and official enrollment numbers are not clear. March is expected to be the month that delivers a true assessment of the impact of the law. For example, final enrollment numbers, health insurance costs, and assessments of the websites back end problem will all be known in March. If everything is working well in March, Moody’s will reverse or reaffirm the downgrade.