Prominent Consumer Credit Scholars And Center For Individual Freedom File Amicus Brief Supporting Plaintiffs In Colorado Opt-out Appeal

On June 2, 2026, Professors Todd Zywicki and Thomas Miller, Jr., together with the Center for Individual Freedom, filed an amicus brief in support of the plaintiff trade associations in National Association of Industrial Bankers, et al. v. Weiser, currently pending before the U.S. Court of Appeals for the Tenth Circuit, sitting en banc. The brief urges affirmance of the district court’s decision enjoining Colorado’s effort to apply its interest-rate caps to loans made by out-of-state, state-chartered banks on the ground that it is preempted by federal banking law.

The amici are well-known scholars of consumer credit markets and financial regulation. Professor Zywicki is a professor at George Mason University’s Antonin Scalia Law School, former Chair of the CFPB Taskforce on Federal Consumer Financial Law, and a leading scholar on consumer finance. Professor Miller holds the Jack R. Lee Chair of Financial Institutions and Consumer Finance at Mississippi State University and has published extensively on consumer lending and small-dollar credit markets. The Center for Individual Freedom is a nonprofit organization focused on economic liberty and limited government. The amici explain that they filed the brief because of the harmful consequences to competition and consumers that would result from a reversal of the district court’s decision.

We recently blogged about an amicus brief we submitted on behalf of a consortium of national and state trade associations of financial institutions in the same case. Our amicus brief describes the issue pending before the Tenth Circuit and the status of it.

Three Principal Arguments

The amici advance three principal arguments.

1. Colorado’s Interpretation Conflicts with the Purpose of Section 521 of DIDMCA

The brief argues that Congress enacted Section 521 of the Depository Institutions Deregulation and Monetary Control Act of 1980 (“DIDMCA”) to place state-chartered banks on an equal competitive footing with national banks after the Supreme Court’s decision in Marquette National Bank v. First of Omaha Service Corp. According to the amici, Congress sought to eliminate discrimination against state-chartered banks by allowing them to export their home state interest rates in their interstate loans in the same manner as national banks.

The amici contend that Colorado’s interpretation of DIDMCA’s opt-out provision would undermine that congressional objective by allowing a single state to impose its interest-rate restrictions on banks chartered in other states. They argue that such a result would effectively negate Congress’s effort to preserve competitive parity between state and national banks and would permit opt-out states to interfere with the banking laws of other states.

2. Colorado’s Reading Is Inconsistent with the Realities of Interstate Lending

The brief next argues that Colorado’s position ignores longstanding principles governing interstate lending. The amici emphasize that consumers historically have been able to obtain credit from lenders located in other states and that the Supreme Court recognized this reality in Marquette. The brief notes that consumers have long crossed state lines to obtain credit unavailable in their home states and that modern technology has simply expanded those opportunities through mail, telephone, and internet-based lending.

According to the amici, treating the borrower’s location as determinative for interest rate ceilings would create substantial operational uncertainty for interstate lending programs, particularly for credit cards and other nationwide products. They argue that a lender must be able to determine where a loan is made based on the location of the issuing bank rather than the location of borrowers, merchants, or individual transactions. Otherwise, the regulatory framework governing interstate banking would become unworkable.

3. Colorado’s Interpretation Would Harm Consumers

The most extensive portion of the brief focuses on consumer welfare and access-to-credit concerns. The amici contend that state-chartered banks play a critical role in serving local communities, small businesses, agricultural borrowers, and consumers who may have difficulty obtaining credit from large national banks. They further argue that partnerships between state-chartered banks and fintech companies have expanded access to credit for underserved and “credit invisible” consumers.

The brief warns that if state-chartered banks are subjected to varying and overlapping interest-rate restrictions imposed by multiple states, many fintech providers may migrate to national bank charters or abandon certain lending programs altogether. The amici argue that such a development would reduce competition, weaken the dual banking system, and diminish access to credit.

The amici also devote significant attention to economic studies addressing interest-rate caps and usury laws. They cite research finding that rate caps reduce credit availability for higher-risk borrowers, particularly subprime consumers, while increasing credit rationing and limiting consumer choice. The brief points to studies involving Illinois, Arkansas, Iowa, New Mexico, and Colorado as evidence that restrictive rate caps reduce access to small-dollar credit products and disproportionately affect consumers with lower credit scores or limited credit histories.

Finally, the amici emphasize that Colorado consumers already experience reduced access to certain forms of credit as a result of the state’s existing regulatory framework. They argue that extending Colorado’s rate-cap regime to loans made by out-of-state state-chartered banks would further reduce competition and make credit less available to Colorado borrowers.

Observations

This amicus brief is noteworthy because it shifts the focus from the statutory text and historical interpretation of DIDMCA to the broader economic and consumer-welfare consequences of the Tenth Circuit panel’s decision. While many of the amicus briefs filed in support of the plaintiffs emphasize congressional intent, federal banking policy, and the structure of the dual banking system, Professors Zywicki and Miller and the Center for Individual Freedom concentrate heavily on the practical effects that Colorado’s interpretation would have on competition, fintech-bank partnerships, and consumer access to credit.

The brief therefore provides the en banc court with a detailed economic-policy framework for evaluating the consequences of allowing a state’s DIDMCA opt-out election to govern loans made by out-of-state state-chartered banks. Together with the other amicus briefs filed in support of the plaintiffs, it reinforces the argument that Congress enacted DIDMCA to preserve parity between state and national banks and that Colorado’s interpretation would upset that balance while reducing credit availability for consumers.

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