Do social transfer programs boost entrepreneurship among low-income populations? We address this question by examining Brazil's Bolsa Família---the world's largest cash transfer program---and its effects on entrepreneurial entry, performance, and economic mobility. Using administrative data covering 2.3 million sole-proprietorships, we track entrepreneurs through the complete business lifecycle---from entry through performance to post-failure employment. We address selection combining instrumental variables---exploiting bunching across program eligibility thresholds---with matching and granular fixed effects. We first show that cash transfers increase transitions into entrepreneurship from both non-employment and wage employment, increasing beneficiaries' representation among entrepreneurs. We then identify systematic performance disadvantages: cash-transfer entrepreneurs exhibit lower survival, business growth, employment creation, and credit access, eventually facing higher rates of tax violations and debt collection proceedings. Performance gaps appear to reflect two mechanisms: managerial constraints---evident in hiring less-educated workers at higher wages with stable employment---and dependency effects revealed by income bunching to maintain eligibility. Yet these same hiring patterns, along with stronger recruitment of racial minorities, produce positive spillovers extending beyond cash-transfer recipients. Examining post-entrepreneurship trajectories, we find that cash-transfer entrepreneurs secure worse jobs after business failure---lower occupational attainment and reduced earnings. However, their wage losses are 61% smaller than those of other failed entrepreneurs---suggesting the entrepreneurial experience builds human capital that disproportionately benefits cash-transfer participants. Our analysis---the first to track cash-transfer entrepreneurs through entry, performance, and post-failure outcomes---reveals that while these programs succeed at poverty alleviation, the businesses they create remain trapped in subsistence, generating neither growth nor pathways to economic mobility.