A federal court has dismissed an unjust enrichment claim against Aetna Life Insurance Co., finding the health insurer can’t be held accountable for costs without an official agreement in place.

Even if Aetna, represented by Elliott Greenleaf, had told health care provider group United Medical as alleged that it was planning to work toward an agreement that would involve Aetna paying United to keep health care costs down, that’s not the same as actually having entered into an agreement, wrote Judge Stephanos Bibas of the U.S. Court of Appeals for the Third Circuit, sitting by designation on the District of Delaware case.