This collection contains data from the Multi-site Family Study on Incarceration, Parenting and Partnering [MSF-IP]. The MSF-IP is an evaluation of a grant program funded by the Office of Family Assistance (OFA) within the U.S. Department of Health and Human Services (HHS), Administration for Children and Families (ACF) to promote or sustain healthy relationships and to strengthen families in which a father was incarcerated or otherwise involved with the criminal justice system (e.g., recently released or on parole or probation). From 2006-2011, grantees were required to serve justice-involved fathers and their committed partners with services to promote healthy marriage; they were also permitted to provide activities to support parenting and foster economic stability. The MFS-IP evaluation was funded to document program implementation and the impact of programming on outcomes such as relationship quality and stability, parenting and co-parenting, family financial well-being, and recidivism. This collection includes data from the impact study, conducted across five grantees: the Indiana Department of Correction, the RIDGE Project (Ohio), the New Jersey Department of Corrections, the Osborne Association (New York), and the Minnesota Council on Crime and Justice. The collection includes de-identified interview data for 1,991 men and 1,482 intimate and co-parenting partners. The interviews took place from December 2008 through August 2014. Couples were first interviewed during the male partner's incarceration (with the timing of baseline interviews not related to the man's admission or release date in most sites) and then interviewed again nine and 18 months after baseline. In the two largest sites (Indiana and Ohio), an additional 34-month follow-up interview was conducted. The interviews were similar in content at each interview wave and for the male and female interviews, but differed based on male partner's trajectory of incarceration and release over the follow-up period. Topics within this collection include demographics, personal characteristics and attitudes, criminal history and behavior, incarceration experiences (including family contact during incarceration), program and service receipt, expectations for release, family structure and functioning, intimate relationship quality, parenting and co-parenting quality, child well-being, employment, housing, substance use, and experiences with reentry.