Recent research finds that doubts about the integrity of the secret ballot as an institution persist among the American public. We build on this finding by providing novel field experimental evidence about how information about ballot secrecy protections can increase turnout among registered voters who had not previously voted. First, we show that a private group’s mailing designed to address secrecy concerns modestly increased turnout in the highly contested 2012 Wisconsin gubernatorial recall election. Second, we exploit this and an earlier field experiment conducted in Connecticut during the 2010 congressional midterm election season to identify the persistent effects of such messages from both governmental and non-governmental sources. Together, these results provide new evidence about how message source and campaign context affect efforts to mobilize previous non-voters by addressing secrecy concerns, as well as show that attempting to address these beliefs increases long-term participation.