As a result of increased life expectancy, high divorce rates, and declining marriage and remarriage rates, older adults have experienced remarkable changes in norms surrounding patterns of partnering and family formation. The family lives of older adults now demonstrate greater heterogeneity and complexity than did those of earlier cohorts. New ways of “doing family” have become more prevalent, particularly in terms of how romantic partnerships are enacted and maintained. Although cohabitation is on the rise, another form of partnering is gaining visibility in Western societies—living apart together (LAT). These relationships are often defined as committed, monogamous intimate partnerships between unmarried individuals who live in separate homes but identify themselves as a couple. This entry provides an overview of LAT relationships in older adulthood including prevalence rates, explanations as to why older adults choose to LAT, and the benefits and disadvantages of LAT in later life.