The Institute for Global Health is currently seeking participants with HIV, who are being treated with Trogarzo (Ibalizumab). This registry study will look at routine healthcare data for 3 years to see how effective and long lasting Trogarzo is, when used in combination with other drugs used to treat adults living with HIV, who have tried multiple HIV medications. No study medications will be administered and no medical procedures will be performed as part of this study. All study information will be collected as part of your routine healthcare.