There is a significant clustering of African-American physics faculty members at Historically Black Colleges and Universities (HBCUs). Almost half (47%) of African-American physics faculty members are employed by physics departments at HBCUs. Physics departments at 30 HBCUs award degrees in physics; this accounts for about 4% (30 out of 746) of the physics-degree-granting departments in U.S. colleges and universities. Half of all African-American physics faculty members work at just 23 departments, meaning that most physics students will never see a black faculty member.