We study the incidence of Social Security taxes on teacher wages and employment. On average, we estimate teachers with Social Security coverage take home 9.6 percent less in wages than observationally similar teachers in similar districts without Social Security coverage. This accounts for about three-fourths of the 12.4-percent total Social Security tax. Moreover, our analysis suggests this is likely a lower-bound estimate of the true incidence of Social Security taxes – under reasonable assumptions, we cannot rule out full (100%) tax incidence on teacher wages. We find no evidence of tax incidence on teacher staffing levels.