"The court ruled in February that the formula is arbitrary and capricious because CMS did not adequately justify key assumptions. The court left open that the formula may be allowed, if justified through notice and comment rulemaking.... CMS could have waited for the court to issue an opinion on a motion to reconsider the decision ... then appeal and request a stay to keep the formula in place through the appeals process. Reversal on appeal may not be a long shot given that a court in Massachusetts upheld the formula in a similar case."