What it does: Founded by Harvard Medical School professors in 1989, the company provides access to top-ranked medical experts to 30 million members worldwide to ensure accurate diagnoses and quality treatment as part of employers' health benefits.
How it grew to become one of healthcare's hottest: Best Doctors attributes its growth to its mission and its employees, now numbering more than 500. The company's peer-selected network of experts reviews medical cases—from patient medical records and lab tests—to ensure correct diagnosis and appropriate treatment, helping to avoid unnecessary healthcare costs.