Dr. Dennis Rosen writes in The New York Times
There are plenty of general pediatricians in the United States — about 70 per 100,000 children. But according to the American Board of Pediatrics, there are only 751 practicing pediatric pulmonologists in the country: one for every 100,000 children. In four states — Alaska, Idaho, Montana and Wyoming, where more than 941,000 children live — there are none. Even in Massachusetts, the state with the highest ratio of pediatric pulmonologists to children in the country (2.6 for every 100,000 children), the wait for an appointment is often several months.
The numbers are similar for other pediatric subspecialties, leading to a shortage of doctors trained to treat problems many children face, like asthma, digestive issues and cancer. And not only are the current subspecialists aging (the average age of pediatric pulmonologists is 52.4), but few pediatric residents are choosing to undergo subspecialty training at the end of their residencies.