External cause code used for length of treatment

Assign the external cause code, with the appropriate 7th character (initial encounter, subsequent encounter or sequela) for each encounter for which the injury or condition is being treated. Most categories in chapter 20 have a 7th character requirement for each applicable code. Most categories in this chapter have three 7th character values: A, initial encounter, D, subsequent encounter and S, sequela.

While the patient may be seen by a new or different provider over the course of treatment for an injury or condition, assignment of the 7th character for external cause should match the 7th character of the code assigned for the associated injury or condition for the encounter.