One of those concerns the constitutionality of the Independent Payment Advisory Board, the body created by the ACA to review and make recommendations concerning Medicare reimbursement rates. The plaintiffs in Coons v. Geithner, which is currently pending in the District Court for the District of Arizona, contend that the IPAB violates the separation of powers. (The lawsuit also contends that the minimum coverage provision exceeds Congress's enumerated powers. Thus, the matter has been stayed pending the Supreme Court's decision.)
What exactly is the challengers' claim against the IPAB? It is essentially a non-delegation doctrine claim, though it is not grounded simply in a claim that the ACA fails to articulate an "intelligible principle" to guide the Board's exercise of its discretion. Rather, the claim concerns both that discretion and the special rules that Congress imposed on itself on the ACA (much like with the Base Closing Commission) as to how it would enact the Board's recommendations in legislation. Here is the summative paragraph of the challengers' most recent filing:
The creation of IPAB represents the most sweeping delegation of congressional authority in history, a delegation that is anathema to our constitutional system of Separation of Powers and to responsible, accountable, democratic lawmaking. IPAB is insulated from congressional, presidential, judicial and electoral accountability to a degree never before seen. It is the totality of the factors insulating IPAB from our nation‘s system of checks and balances that renders it constitutionally objectionable.I have not spent a great deal of time investigating this, but it does not strike me as a particularly promising claim, especially to the extent that it relies on the parliamentary rules Congress has imposed on itself. Ultimately, Congress never need accept any of IPAB's recommendations; they must be affirmatively enacted by Congress before they become law. So I'm not sure how there could be a non-delegation problem.
But, hey, many of us were saying similar things, about other constitutional claims, in March 2010. You never know.