Men who are doctors earn about $12,000 more per year than women doctors, according to a US study published on Tuesday in the Journal of the American Medical Association.
The differences persisted even after adjusting for factors like specialty, academic rank and work hours, said researchers at the University of Michigan Medical School.
"The gender pay disparity we found in this highly talented and select group of physicians was sobering," said lead study author Reshma Jagsi, associate professor of radiation oncology.
The survey focused on 800 physicians who had received a competitive early career research grant from the National Institutes of Health in 2000-2003. At the time of the salary assessment, all were considered mid-career.
They answered 39 survey questions on age, medical specialty, marital status, work hours, time spent in research, number of peer-reviewed publications, location, race, additional grants, leadership roles and other degrees.
"People point to a lot of possible reasons for pay disparities, so we examined a population in which you would be least likely to pick up gender differences in salary," said Jagsi.
"After we adjusted for a host of factors that could explain pay differences, we unmasked a pay disparity of $12,001 a year, or more than $350,000 over a career."
Overall, the average annual salary was $200,422 for men and $167,669 for women, a difference of $32,764.
When researchers adjusted for differences driven by medical specialty, the salary gap narrowed to $17,874 for the men.
An adjustment for all variable factors led to the final gap of $12,001.
Jagsi described the divide as "both surprising and disturbing" and expressed hope that the research would inform future policy discussions on how to ensure equal pay for equal work.
Senior author Peter Ubel, a professor at Duke University's Fuqua School of Business and its Sanford School of Public Policy, said medical centers should take steps to assure fairer pay.
"For all we know, women are paid less in part because they don't negotiate as assertively as men, or because their spouse's jobs make it harder for them to entertain competing job offers," Ubel said.
"Nevertheless, whatever the reason for the salary disparity, academic medical centers should work to pay more fairly. A person's salary should not depend upon whether they have a Y chromosome."