We examine the staggered adoption of additional educational requirements (“150‐hour rule”) for Certified Professional Accountants (“CPAs”) to understand the effects of occupational licensing on minority participation in professional labor markets. The 150‐hour rule increased the educational requirement for CPAs from 120 to 150 credit hours, effectively adding a fifth year of study. We find a 13% greater entry decline following the requirement's enactment for minority than nonminority CPA candidates. Our analyses of parental income and financial aid availability point to a socio‐economic status channel explaining the differential entry declines. Studying exam passing patterns, professional misconduct, and job postings we find a deterioration, or at best, no change in CPA quality following enactment.This article is protected by copyright. All rights reserved