Management trainee Bankers Trust Company, New York City, 1963-1965. Managing director Castleman and Company, Houston, 1965-1971. Director program planning, economic United States Department Housing and Urban Development, Fort Worth, Dallas, 1971-1973.
Vice president, office manager Booz Allen and Hamilton, Dallas, Houston, 1973-1985. Managing director Castleman Group, Houston, 1985-1987. Chief Executive Officer Kelsey-Seybold Clinic, P.A., 1987-1995.
President physician resources division Caremark International, Inc., 1994-1996. President Scripps Clinic, La Jolla, California, 1996-1999. Chief Executive Officer Physia Corporation, Houston, 2000—2004, Syntiro Healthcare Services, Inc., Mill Valley, California, since 2001.
Chairman Electro-Optical Sciences, Inc., Irvington, New York, since 2003.