Not all residency programs are funded by Medicare. And even among those that are funded by Medicare, many have additional slots that are unfunded but exist anyw

Not all residency programs are funded by Medicare. And even among those that are funded by Medicare, many have additional slots that are unfunded but exist anyway because a resident provides cheap labor. If a physician decides to change specialties and do a second residency, these unfunded programs and slots are their only options because Medicare won't pay for second residencies.