Question: The provider diagnosed post-traumatic headache. Is G44.3 the correct ICD-10 code for this condition? Illinois Subscriber Answer: Yes and no. The G44.3- (Post-traumatic headache) code is accurate, but not specific enough. Follow these instructions once you arrive at G44.3- in the code book: Intractable reminder: The deciding factor in these ICD-10 codes is whether the headache was intractable or not intractable. An intractable headache, also known as a refractory headache, is a “persistent headache that is difficult to treat or fails to respond to standard and/or aggressive treatment modalities.” A headache that is not intractable would respond more readily to treatment.