This study investigates why cohabitation is so common even among those most committed to marriage. To understand the variety of meanings to co-residence, this study interviewed each member of 23 heterosexual, middle-class couples, totaling 46 interviews. Research categorizes cohabitations as extensions of dating, alternatives to marriage, or trial marriages, but interviews highlight the prevalence and importance of a fourth, under-researched category, cohabitation as a precursor to marriage. Before cohabitation, these couples expressed marriage intentions and viewed cohabitation as a promise to marry in the future. Why do couples committed to marriage still decide to cohabit? The data show that cohabitation as a precursor to marriage is explicitly connected to increasing marriage requirements in that couples cohabit instead of marry to meet the rising bar to marriage. While research has shown financial security and stability impact low-income couples, this study illustrates how these barriers have similar effects for middle-class couples.