Abstract Debates about the taxation of business owners often center on the distributional effects of these taxes, particularly the degree to which they affect workers. Drawing on a new linked owner-firm-worker data set created from U.S. administrative tax records, I analyze how an increase in the top marginal tax rate faced by business owners affected the earnings of their employees. I use panel difference-in-differences methods to compare the earnings of workers in similar firms but whose owners were differentially exposed to the tax increase. I estimate that 11–18 cents per dollar of new business income tax liability was passed through to employee earnings. I find no change in employment in response to the tax increase. The responses were generally associated with lower earnings growth, not changes in workforce composition. The burden was not borne equally by all workers. Essentially all of the workers’ share of the burden was borne by those in the top 30% of the earnings distribution, highlighting that the ultimate distributional effects of the policy depend not only on the share of the burden borne by workers but on the shares borne by different types of workers. Furthermore, since the owners bore the majority of the burden, the policy resulted in a decrease in after-tax earnings inequality between top-bracket owners and lower-bracket workers. I discuss the implications of the findings for the mediating labor market mechanisms and for welfare analyses of income taxation using a marginal value of public funds framework.