I used to think the same way about this until I realized that the 2 years of medical school are just that, medical school, with a spoonful of OMM. Some people only want to practice OMM, and some want to be extremely good at it. And these people are the ones that do 3 year OMM residencies. The FP's who go back to do a one year OMM residency after doing their AOA residency also get board certified in OMM like the 3 year residents. Now there is no other way to get the certification. But some just do it to get more proficient at OMM. I would never do it because the amount of OMM i think that is feasible to use in FM is about the amount I am already comfortable doing as a student. And I don't even plan to do an AOA residency anyway. FM is wide open for DO's, and I want to go to a particular program that is soon to be dually certified, but right now is just allopathic.