In 1968 78% of 26-year-olds in the U.S. lived with a spouse, and 12% lived with their parents. By 2018 30% lived with parents and only 24% lived with a spouse.
From Apartment List:
Starting with 2007 – the year before the collapse of the housing market bubble – we see the beginning of a steady divergence in young adult housing composition that has continued to the present-day. This is a period characterized by economic recession, ballooning student debt, and even as the economy recovered, a dearth of affordable housing options in the cities with the best job opportunities. All of these factors put downward pressure on young adults who, in previous generations, would have been ready to start their own households. Instead, 25-34-year-olds2 today are 46 percent more likely to live with a parent than in 2007, 32 percent more likely to move in with a partner before getting married, and 19 percent more likely to have a non-family roommate. In contrast, the likelihood of living with a spouse or a child have declined steadily, as cultural norms around marriage and education have encouraged millennials to start families later in life.