The historic increase in U.S. incarceration rates made the transition from prison to community common for poor, prime-age men and women. Leaving prison presents the challenge of social integration--of connecting with family and finding housing and a means of subsistence. The authors study variation in social integration in the first months after prison release with data from the Boston Reentry Study, a unique panel survey of 122 newly released prisoners. The data indicate severe material hardship immediately after incarceration. Over half of sample respondents were unemployed, two-thirds received public assistance, and many relied on female relatives for financial support and housing. Older respondents and those with histories of addiction and mental illness were the least socially integrated, with weak family ties, unstable housing, and low levels of employment. Qualitative interviews show that anxiety and feelings of isolation accompanied extreme material insecurity. Material insecurity combined with the adjustment to social life outside prison creates a stress of transition that burdens social relationships in high-incarceration communities.