Chiari Malformation Question

Hi All,

I am new to neurosurgery coding and I noticed that there are 4 different codes for Chiari Malformation based on what type of malformation the patient has. However, if the physician just documents Chiari Malformation without listing type I, type II, etc. is there a default code to use or can this not be coded at all without the type specified?

Any help is greatly appreciated!

Chiari Malformation Question