Although there has been considerable enthusiasm for public service motivation (PSM) research in recent years, two of PSM's fundamental assumptions have been relatively untested: its impacts on job choice and on job performance. Using panel data from two different studies, we offer stronger observational tests of these core assumptions. The findings provide mixed evidence. When testing PSM's effect on employment choice, we find that PSM measured during a law student's first year predicts the sector in which they are employed after graduation three years later. In a separate study investigating PSM's effect on job performance, we find that government employee PSM does not predict employee absenteeism or supervisor assessments of their in-role and extra-role performance. Our findings support recent calls for a more nuanced theory and analyses of PSM to help better understand its implications for recruiting, retaining, and motivating the workforce used to provide public goods and services.