Convert ICD-10 Code G44.311 to ICD-9

Source ICD-10 Code		Target ICD-9 Code
G44.311 Acute post-traumatic headache, intractable		339.21 Ac post-trauma headache
Approximate Flag - The approximate mapping means there is not an exact match between the ICD-10 and ICD-9 codes and the mapped code is not a precise representation of the original code.

ICD-10 to ICD-9 crosswalk for code G44.311 - acute post-traumatic headache, intractable based on the most recent General Equivalence Mappings (GEMS) information.