Miller was raised in Miami, the son of Susan and Leonard M. Miller. His father founded the Lennar Corporation in 1954. Miller worked for Lennar as a youth first mowing lawns and then in roofing. Miller has a B.S. from Harvard Business School (1979) and a law degree from the University of Miami (1982).
After school, he joined Lennar Corporation. In 1990, Lennar was appointed director of Lennar. In 1992, Miller successfully presided over damage claims resulting from Hurricane Andrew which devastated South Florida causing over $20 billion in damage; as the largest house builder in Florida, Lennar faced numerous lawsuits. In 1997, he succeeded his father as chief executive officer. Miller also served as president of Lennar from 1997 to 2011. Miller preside over the expansion of the firm into commercial properties after buying $1.0 billion in land in California in the 1990s which he correctly predicted would rebound; he also simplified the homebuilding process and brought down costs by automatically including what the industry deemed as an upgrades (tile, trim, and flooring) as standard with every Lennar home. In markets where baby boomers were moving that had limited available land such as Miami, Lennar shifted construction away from single family houses to multi-unit condominiums which correctly predicted demand.
Miller also presided over a number of acquisitions in the 1990s and 2000s. In 1995, Lenner acquired two homebuilders in Texas; in 1996, he acquired and two homebuilders in California. In 1998, Lennar acquired the North American Title Company, title and escrow service company in Arizona, California, and Colorado. In 1998, Lennar had $2.9 billion in sales with 10,777 houses sold. In 2000, Lennar purchased U.S. Home Corporation of Houston for $1.2 billion which extended Lennar's geographic footprint into the Northeastern United States; expanded their offerings "active-adult" real estate market; while also doubling Lennar's sales. In 2001, Lennar acquired nine more homebuilders. As of 2004, Lennar had built more than 500,000 houses with annual revenues of $6 billion. In 2010, he purchased two loan portfolios - with a combined unpaid balance of $3.05 billion - from the FDIC for $243 million.In 2012, Lennar was the third largest homebuilder in the United States.
Miller also serves as CEO of Lennar Homes of California Inc., Fidelity Guaranty and Acceptance Corp; as well as the Director of: Riley Property Holdings LLC., Union Bank of Florida, and Builder Homesite Inc.His total compensation for 2014 was: $17,909,543. As of October 2014, his net worth is estimated to be $900 million.
Miller is known for having an unorthodox method of building company spirit and teamwork: he has his employees memorize and read aloud a complicated version of the nursery rhyme, Little Red Hen. When the employees inevitably make mistakes, their co-workers chime in and the rhyme is completed via teamwork.
Lennar started as a single-family homebuilder in Miami, Florida, in the early 1950s and it has grown by acquisition. It concentrates on single-family attached and detached homes and purchases land through unconsolidated entities. Rialto Capital Managements is part of Lennar’s financial arm. Rialto invests in real estate and manages funds that invest in real estate. It also provides mortgage financing, title insurance, and closing services. While Lennar is an originator, it sells its origination pipeline in the secondary market and doesn’t retain servicing.