It adds about 17-20K to your salary yearly is the estimate I always hear.
I know that OMT payments from medicare are based on how many areas are being treated up to 10 regions. Payments start at $25 for "1-2 body regions" and go up to an unknown amount (values based on medicare, insurance payments are higher). The value I always hear is that you can justify $35 worth of manipulation on any patient regardless of illness and that anyone with MSK pain can justify up to ten regions which I one time anecdotally heard is $75, but I'm not sure if that is true since I only heard it once from an attending.
The thing is that as a FP you'll easily be seeing 20+ patients a day. Even if you're only doing the absolute bare minimum to half (10) of them you can justify $350 a day from just quick manipulations. Assuming a 5 day week you're at $18,000 yearly added to your salary right there by just doing the bare minimum to a handful of pts a day. Obviously those who go all out can (and generally do) make a killing off of it since its actually a lot of money to make for how little time it takes.
and some OMM is better than none if you want to take advantage of it. Sure some programs barely devote any time to OMM, I'm a student at one of them. But some programs really do integrate it well into their program as well. But no matter what, its involved in some level and institutionally allowed/encouraged. Barring a desire to be in a certain location with limited AOA spots, I honestly cannot justify going to an ACGME FP program when everyone complains about FP salaries and this is pretty much a 16.7% salary increase (potentially much more) with almost no work involved.
With all of this said, maybe I hold a radical crazy opinion on FP residencies. I could accept that I might
. I'm usually the one who is on the other side of this argument, giving the AOA a hard time and encouraging DOs to try to really pull out the razzle dazzle and lock up the ACGME spots for "prestige" (cant believe i used that word). But I sort of view FP as a unique situation in which the AOA has the better offering, since it does integrate some-to-lots-of OMT, and because many of the FP spots don't have to compete with other programs on the ground to get the more broad training exposure that makes FP degrees more economically viable once you take that skillset to the office (minor surgeries, obstetrics, gynecology, and no competition from IM residents for the more complex organ diseases).
And btw, the reasoning for constantly opening the FP spots is because FP (and to some degree pediatrics) are not capped by the 1997 law. If you create a FP spot in an underserved area, it gets funded directly and doesn't count against the cap. This allows new programs to get funded and existing programs to open up new programs (or satellite programs) in FP even though all other fields are capped. For those curious, almost all pediatric residencies comes from a separate source of money which has expanded and contracted through the years, but is capable of expanding and creating new programs at any time if the money finds its way there.