>>Is it what you mean http://en.wikipedia.org/wiki/Clinical_coder ?

Yes. There are online courses you can do to cover anatomy, clinical etc after which you need to pass an exam to be an accredited coder. I can't imagine you'd have to much trouble with that. Now is a good time: ICD-10 is new for everybody in the US so everybody is undertaking training and up-skilling. Meanwhile your colleagues and peers would be very precise types who care a great deal about exactness and apostrophes. ;-) The other issue is that you can leverage the qualification into other directions in health information, including Electronic Health Records or management. Having both HIM and development hats would be quite desirable if you wanted to oversee projects.

Just a thought. Easy enough to do the courses etc while keeping the day job.