On November 26, 2019, the US Court of Appeals for the Fifth Circuit held in Ultra Petroleum Corp. v. Ad Hoc Committee of Unsecured Creditors of Ultra Resources1 that the US Bankruptcy Code limits in certain respects the right of creditors to enforce contractual claims for a “make-whole” premium owed under a note agreement as the result of the debtor’s prepayment of the notes. The Ultra Petroleum case may ultimately lead to a decision addressing the unresolved questions of whether, and in what circumstances, a claim for a make-whole premium must be disallowed as “unmatured interest” under Section 502(b)(2) of the Bankruptcy Code.