Patient presents with complaints consistent with shoulder osteoarthritis.  Symptoms include progressively worsening shoulder pain, stiffness, and limited range of motion, particularly with abduction and external rotation.  Pain is described as aching or deep and may be worse at night or with changes in weather.  Patient reports difficulty with activities of daily living such as dressing, reaching overhead, and sleeping on the affected side.  On physical examination, crepitus is palpable with shoulder movement.  Reduced active and passive range of motion is noted.  Tenderness to palpation is present over the glenohumeral joint.  Muscle weakness may be present in the rotator cuff muscles.  Radiographic imaging of the shoulder reveals joint space narrowing, osteophyte formation, and subchondral sclerosis consistent with osteoarthritis.  Differential diagnosis includes rotator cuff tear, frozen shoulder, and acromioclavicular arthritis.  Diagnosis of primary osteoarthritis of the shoulder is made based on clinical presentation, physical exam findings, and radiographic evidence.  Treatment plan includes conservative management with nonsteroidal anti-inflammatory drugs (NSAIDs), physical therapy focusing on range of motion and strengthening exercises, and activity modification.  Patient education provided regarding the condition and its management.  Referral to orthopedic surgery may be considered if conservative treatment fails to provide adequate relief.  Follow-up scheduled to monitor symptoms and response to treatment.  ICD-10 code M19.011 for primary osteoarthritis, right shoulder, and M19.021 for primary osteoarthritis, left shoulder, are applicable.  CPT codes for evaluation and management, physical therapy, and injections may be used as appropriate for billing purposes.