Combined training consists of a coherent educational experience in two or more closely related specialty or subspecialty programs. The educational plan for combined training is approved by the specialty board of each of the specialties to assure that resident physicians completing combined training are eligible for board certification in each of the component specialties. Each specialty or subspecialty program is separately accredited by ACGME through its respective specialty review committee. The curriculum components that comprise the combined training must be taken from those experiences that have been approved by the Residency Review Committees in each of the specialties. The duration of combined training is longer than any one of its component specialty programs standing alone, and shorter than all of its component specialty programs together.
A special agreement exists with the American Board of Anesthesiology (ABA) whereby an applicant may fulfill the training requirements for certification in pediatrics and anesthesiology by completing five years of combined training. An applicant may not take the certifying examination of the ABP until all training requirements in both programs has been successfully completed.
Program requirements and other information can be found here:
Source: American Board of Pediatrics