MTHFR FAQ
What ICD9 code do you use for MTHFR?
Ans. We haven't found a specific code for MTHFR, but we use 270.4. This is the code that comes up on ICD9Data.com search. There is a second code 270.9 which is an unspecified disorder of amino-acid metabolism could be used, but we believe 270.4 is the best code to use.