Today, the Supreme Court refused to hear an Obamacare case.

When federal district court judge Reed O'Connor held that Obamacare was unconstitutional in December 2018, health insurance stocks crashed hard. Molina Healthcare (MOH 1.44%) dropped 8.9%. Tenet Healthcare (THC 1.99%) lost 6.8%; Cigna (CI) fell 3.3%.

Last month, a federal court of appeals partially reversed the district court's opinion, sending the case back down to be reheard. That news left the Affordable Care Act in place for the time being, and health insurance shareholders were happy again. Centene (CNC 1.15%) jumped up 4% and Molina rose 3%. Shares of Wellcare (WCG) went up over 2%. 

judge's gavel

Image source: Getty Images

Democrats tried to argue that this Obamacare case is an emergency and the Supreme Court needed to hear it right away. Not surprisingly, the Supreme Court decided it's not an emergency, and in a one-sentence ruling declined to hear the case now. (This ruling does not affect the Supreme Court's authority to hear the case down the road).

In 2012, the Supreme Court upheld the constitutionality of Obamacare's individual mandate, holding that Congress has the authority to pass this legislation under its power to tax. Congress since voided the tax provision that was the basis of the individual mandate, inspiring more litigation. 

In December, the federal court of appeals ruled that the individual mandate in Obamacare is now unconstitutional because without a tax provision, Congress has no authority to force people to be covered by health insurance. 

Since the Supreme Court refused to hear the emergency appeal, it's up to Judge O'Connor to decide if any part of Obamacare remains valid. The market didn't expect the Supreme Court to grant an emergency review, so health insurance stocks remain mixed on today's news.