In Neder v. United States, 527 U.S. 1 (1999), the Supreme Court held that proof of materiality is required for convictions under the federal mail, wire and bank fraud statutes. During the past 20 years, the federal courts have endeavored to apply the complex common law concept of materiality to the federal criminal law context. The Supreme Court’s recent decision in Universal Health Services, Inc. v. United States ex rel. Escobar, 136 S. Ct. 1989 (2016), a civil case involving the False Claims Act, provided the federal appellate courts with an ideal opportunity to reconsider materiality standards in federal fraud cases. In particular, criminal fraud defendants have argued that Escobar’s “subjective” materiality standard should be applied in mail, wire and bank fraud cases involving financial institutions. Thus far, these arguments have failed. Instead, the Courts of Appeals have endorsed an objective materiality standard tethered to what a reasonable bank would do—not the behavior of renegade lenders. This Article explores judicial treatment of materiality in federal criminal fraud cases, and investigates the many challenges that criminal fraud defendants face when they try to undermine the government’s proof of materiality by attacking the imprudent or reckless actions of banks and other lenders.