ICD-10-CM > M00-M99 > M05-M14 > M11 > M11.8 > M11.87 M11.87 Other specified crystal arthropathies, ankle and foot Non-Billable/Non-Specific Codes M11.871Other specified crystal arthropathies, right ankle and footM11.872Other specified crystal arthropathies, left ankle and footM11.879Other specified crystal arthropathies, unspecified ankle and foot