Entry ban could cause doctor shortages in Trump territory, new research finds
President Donald Trump signs a revised executive order in September at the Pentagon in Washington, D.C., taking Iraq off the U.S. travel ban list.

President Donald Trump's executive order suspending entry to the U.S. by people from six Muslim-majority nations could reduce the number of doctors in areas with high percentages of Trump supporters, according to researchers at Harvard Medical School and MIT.

Swaths of Appalachia and the Rust Belt could be disproportionately affected, the researchers who analyzed data about physicians in the United States found.

As many as several hundred doctors from the six countries affected by Trump's new executive order will not be able to begin medical residencies this year unless waivers are granted, Atul Grover, executive vice president of The Association of American Medical Colleges, told NBC News. The AAMC is still calculating the precise number of doctors directly affected by the latest ban and is expected to release a breakdown of specific numbers within the week.

Residency programs are a pathway for foreign-born doctors to become physicians in the U.S. and have played a critical role in preventing doctor shortages in rural and low-income areas.

The new research from economists and medical professionals at Harvard and MIT found that doctors from the countries affected by Trump's latest immigration-related executive order — Iran, Somalia, Sudan, Yemen, Syria and Libya — have tended to cluster in states like Indiana, Michigan, Ohio, Pennsylvania and West Virginia. Residents of working class areas in those states tend to have higher incidences of health problems like obesity, diabetes, and alcoholism and also tended to give Trump big boosts of support in the election, according to The Economist.

As the below maps show, doctors from the six affected countries have tended to serve these areas.