The prevalence, consequences, and unequal racial distribution of the experience of parental and own imprisonment have been well documented in scholarship on mass incarceration in the United States. However, much of our knowledge of the reach of mass incarceration into family life is focused on incarceration of a parent, romantic partner, or child, to the exclusion of other important relationships. Using data from a nationally representative survey of U.S. adults (N=2,029), this study introduces a set of new descriptive measures of family incarceration to provide a comprehensive picture of the demography of family incarceration and its unequal distribution across racial/ethnic groups: degree, generational extension, and permeation. The analysis shows that Black adults in the U.S. are not only more likely to have ever experienced family incarceration but are also likely to have had more family members incarcerated and to have had family members from more generations ever incarcerated than those of other racial and ethnic groups.