Recent demographic trends have produced a distinctive fertility regime among young women and men in their teenage years and twenties. Data from the NLSY, 1997 cohort, show that by the time the cohort had reached ages 25-30 in 2010, 83% of births reported by women and 88% of births reported by men had occurred to non-college graduates. In addition, 59% of births had occurred outside of marriage. Moreover, 67% of women (and 65% of men) who reported a birth had at least one child outside of marriage, a figure that rose to 74% among women (and 71% among men) without 4-year college degrees. It is now unusual for non-college-graduates who have children in their teens and twenties to have all of them within marriage. The implications of these developments are discussed in light of differing transitions to adulthood of non-college-graduates versus college-graduates and growing social class inequalities in family patterns.