Religious causes and institutions continue to comprise the top-ranked category of recipients of philanthropic giving in the United States. Not all faith communities, however, give at the same level or rate. In 2017, the Institute for Social Policy and Understanding conducted a study revealing that US Muslims gave less to religious causes and institutions than other US faith groups. This article seeks to explore six different but related reasons that may account for why US Muslims give less, two of which are purely demographic in nature. The other possible reasons relate to different cultural and religious understandings of giving that are contextual to the experience of US Muslims living in a post-9/11 world.