Abscess of tendon sheath, unspecified shoulder

This code signifies an infection with pus formation within the synovial sheath surrounding a tendon in the shoulder region. This inflammatory process can lead to pain, swelling, and restricted movement of the affected shoulder.

Apply this code when documentation clearly indicates an abscess involving a tendon sheath in the shoulder, and the specific shoulder (right or left) is not specified. This diagnosis is typically supported by physical examination findings, imaging (e.g., ultrasound, MRI), and sometimes aspiration of purulent material.

• Ensure the documentation explicitly states "abscess" and "tendon sheath" in the shoulder.
• If the specific shoulder is documented (e.g., right or left), use the more specific code (M65.011 or M65.012).
• Do not confuse with tenosynovitis without abscess (M65.8) or other shoulder infections not involving the tendon sheath.