To test Abatacept, we are going to treat 15 patients with moderate to severe Alopecia Areata for 6 months. Each person enrolling into this study will receive the active study drug. The effectiveness of the medication will be measured by changes in hair re-growth as determined by physical exam and photography, as well as by patient and physician scoring. Patients will be followed for another 6 months off of the drug to see if the effects of treatment last and if there is delayed response. We have recently changed the study to allow testing of abatacept in a few patients with alopecia totalis and universalis.