I did the same as you; MD residency/fellowship. I get emails all the time about becoming board certified by our fellow DOs
And I had the same motivation as you. Plus, I like being a DO and believe in the tenants, etc. I mean it makes sense, be a DO and get board certified by osteopaths too, why not?
It appears that the ABPN is slightly more accepted than the DO boards in my experience. Because the ABPN is such a horrible monopoly more popular, I would definitely do that board certification at a minimum, and then do the DO boards on top of it if you really want
I would have totally done the DO board **but** they (we?) still have the oral board requirement. If you remember the ABPN got rid of that around 10 years ago because having a totally fair interview/exam is damn near impossible. Instead they require three interviews done by someone who is board certified.
Not only is it over a grand for the board exam (which OK is cheaper than the ABPN), but you have to fly out there to take the test, take time off...I mean it's a pain the arse
I summary, I like the idea of DO board certification but I don't want to pay the money/time that it costs. But if you have the free time and the money, and you have an interest at teaching at a DO school in the future, you should do it.
good luck!