S86.91Strain of unspecified muscle and tendon at lower leg level

S86.91 is the ICD-10-CM diagnosis code for strain of unspecified muscle and tendon at lower leg level. It belongs to category S86 (injury of muscle, fascia and tendon at lower leg level), block S80-S89 (injuries to the knee and lower leg) and chapter 19 (injury, poisoning and certain other consequences of external causes). It is a header code, so it can't be reported by itself; one of its 3 subcodes must be used instead.

Within S86.9, choose S86.91 (Strain of unspecified muscle and tendon at lower leg level) only when documentation doesn't support a more specific option: unspecified injury of unspecified muscle and tendon at lower leg level (S86.90), laceration of unspecified muscle and tendon at lower leg level (S86.92) and other injury of unspecified muscle and tendon at lower leg level (S86.99).

Codes in this range require a 7th character: A for initial encounter, D for subsequent encounter and S for sequela. Use placeholder "X" characters to fill any empty positions before the 7th character.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.