Vast differences between the U.S. city of today and that of a quarter-century and half-century ago call for a rethinking of conventional frameworks that provide an explanation of clustering/segregation along racial/ethnic lines. Accordingly, we put forth a new framework, market-led pluralism, that better fits today's realities. Existing frameworks-assimilation, stratification, and resurgent ethnicity-miss a central element of today's racial/ethnic residential mosaic, the market makers. At the center are housing developers who continually unveil new urban spaces with culturally open communities; lending agencies that, encouraged and supported by government policy, provide highly affordable mortgages to an increasingly wide range of households; real estate brokers and agents for whom the discriminatory practices of the past are illegal, profit reducing, and often beside the point in today's marketplace; consumers whose preferences emphasize class-type elements such as amenities in housing and neighborhood, tempered by affordability; and communities that impose their own development agenda, or lack thereof, on the housing market. The efforts of these market makers are facilitated by pervasive and fluid information (e.g., via the Web, e-mail, cell phone); procedures that are more systematized, automated, and transparent; and well-working market mechanisms. Fleshing out market-led pluralism is done in five steps focusing on (1) building (developers-builders), (2) lending (banks, mortgage agencies, government policy and entities), (3) selling and renting (real estate practices, including discrimination), (4) consuming (buyers, renters, their preferences), and (5) local communities (annexation, zoning, development agendas, cooperative agreements among communities). Empirical support for the framework is drawn from secondary data and key-informant, protocol-driven interviews, largely focused on the Columbus, Ohio, metropolitan statistical area.Las vastas diferencias entre las ciudades estadounidenses de la actualidad y las de hace un cuarto de siglo y medio siglo exigen la reconsideración de las estructuras convencionales que proporcionan una explicación del agrupamiento/segregación a lo largo de las líneas raciales/étnicas. De acuerdo con esto, proponemos una nueva estructura, un pluralismo dirigido por el mercado, que se ajusta mejor a la realidad actual. Las estructuras existentes, asimilación, estratificación y gruposétnicos resurgentes, carecen de un elemento central en el mosaico