Shoulder impingement is a common cause of shoulder pain in the athlete older than 40 years. Although shoulder instability and cuff tendinitis remain common in the younger athlete, rotator cuff degeneration and bone abnormalities are largely responsible for shoulder pain in the older athlete who participates with sports. A history of subacromial pain with movement, aggravated by overhead activities and interfering with sleep, is classic. Impingement signs are positive, although rotator cuff strength is variable and depends on the extent of rotator cuff damage. Conservative treatment consists of activity modification rather than complete rest and is centered around a home rehabilitation program designed to maintain or improve shoulder movement and strength. Surgical treatment consists of two parts. The space within the coracoacromial arch is increased with acromioplasty and, if needed, acromioclavicular joint resection. Arthroscopic or open techniques can be used. Tendon surgery is related to the amount of tendon damage, the activity level of the patient, and the amount of bone abnormality. A postoperative rehabilitation program is critical