Although the physician assistant (PA) profession was created to bolster the primary care workforce, PAs have assumed increasing roles in subspecialties. This paper compares specialty prevalence between physicians and physician assistants, analyzes trends in PAs' specialty choices from 1997 to 2006, and suggests options for influencing these specialty choices in the future. The number of PAs is growing more rapidly in surgical and medical subspecialties than in primary care. Salaries loosely correlate with specialty choice, especially among specialties with the highest income. If there is a societal interest in encouraging PAs to practice in primary care, new economic or educational policies may be required.