ICD-10-CM > G00-G99 > G89-G99 > G90 > G90.5 > G90.52 G90.52 Complex regional pain syndrome I of lower limb Non-Billable/Non-Specific Codes G90.521Complex regional pain syndrome I of right lower limbG90.522Complex regional pain syndrome I of left lower limbG90.523Complex regional pain syndrome I of lower limb, bilateralG90.529Complex regional pain syndrome I of unspecified lower limb