Race and ethnicity are notoriously difficult to measure in the U.S., and health scholars have shown over the last two decades that the common, large racial/ethnic categories of “Black,” “Asian,” and “Hispanic” mask considerable heterogeneity within groups, often based on country of origin. Recent work by Jen’nan Read (with Scott M. Lynch and Jessie S. West) found that the “White” racial category masks just as much or more heterogeneity in health as these other common categories, in part because recent “white” immigrants from the Middle East and North Africa differ substantially from white immigrants from Europe and native (i.e., 3+ generation) whites in the U.S. As a consequence of this and other studies in recent years by Dr. Read, Dr. Read has been consulting with the Census Bureau in redesigning questions measuring race/ethnicity in upcoming censuses.