Here's what to know about the five richest physicians in the U.S., as of March 28:
1. Thomas Frist Jr., MD. $26.6 billion net worth.
A former Air Force flight surgeon, Dr. Frist founded Nashville, Tenn.-based HCA Healthcare with his father in 1968 and still owns more than 20% of the company with his family.
2. Patrick Soon-Shiong, MD. $6.3 billion net worth.
Dr. Soon-Shiong invented the cancer drug Abraxane, which became a huge success for its efficacy against pancreatic cancer. He sold his drug companies for a total of $9.1 billion — Abraxis in 2010 and American Pharmaceutical Partners in 2008.
3. Leonard Schleifer, MD, PhD. $3.5 billion net worth.
Dr. Schleifer is the co-founder and CEO of drug company Regeneron. He took Regeneron public in 1991 and owns nearly 4% of the company.
4. Phillip Frost, MD. $1.9 billion net worth.
Dr. Frost runs diagnostics-maker Opko Health. He founded drugmaker Ivaxin 1987 and sold it for $7.6 billion in 2005. He also joined Key Pharmaceuticals in 1972, reformulated its asthma drug and sold it for $836 million in 1986.
5. Gary Michelson. $1.8 billion net worth.
A retired orthopedic and spine surgeon, Dr. Michelson holds more than 340 patents for orthopedic devices. He became a billionaire after a $1.35 billion settlement with Medtronic in 2005.