Since you insist on comparing pilots to dr's think of regionals as residency.
Medical residency salary in USA

A resident physician in the United States receives an average annual salary ranging from between $41,526 – $62,856. In addition, a bonus of about $5, 000 will be credited to his or her account. In fact, a resident physician receives his or her total earnings ranging from between $41,699 – $62,647 per annum.

Or are residents not specialized?