Question: Our provider recently submitted a claim with a final diagnosis of loose body in the right elbow. What ICD-10 code would I choose for this condition, and what is a “loose body”? Pennsylvania Subscriber Answer: For this patient, you’ll report M24.021 (Loose body in right elbow) as a diagnosis. According to the ICD-10 code book instructions under M24.0- (Loose body in joint), a loose body in a joint “consists of fragments of bone and/or cartilage that float in the joint. These can float freely, or cause the joint to lock or catch.” With the exception of M23.4- (Loose body in knee), you’ll find all the loose body in joint diagnosis codes in the M24.00 (Loose body in unspecified joint) through M24.08 (Loose body, other site) code set. These codes are separated by anatomy and laterality, so make sure you take both of those factors into consideration when choosing the most specific diagnosis code possible for loose body in joint.