I examine the effects of mandatory occupational licensure on the quality of Certified Public Accountants (CPAs) using the staggered state-level adoption of the 150-hour Rule (the Rule). Although the Rule reduces the number of entrants into the profession, an analysis of labor market outcomes shows that accountants subject to the Rule are more likely to be employed at a Big 4 public accounting firm and specialize in taxation. However, accountants subject to the Rule have the same likelihood of promotion, the same duration until promotion, and exit public accounting at faster rates than their non-Rule counterparts. Moreover, Rule accountants earn a wage premium relative to non-Rule accountants. These findings suggest that restrictive licensing laws reduced the supply of new CPAs and increased rents to the profession without drastically improving quality in the labor market.