The classification of test-takers into ethnic and racial groups ensures individuals and groups, identified in Title VI and VII of the Civil Rights Act of 1964 and the 14th Amendment to the Constitution of the United States, are protected from adverse treatment (Camilli, 2006). The United States Office of Management and Budget (OMB) suggests that respondents to ethnic and racial data collection efforts have the option to select with more than one ethnicity and/or racial group. This paper focuses on the impact on the calculations of differential item functioning (DIF) statistics when respondents can select all ethnic and racial categories that apply. Over 5,000 participants were recruited to take a full-length SAT® or PSAT/NMSQT® pilot test. In addition to the pilot test, the test-takers also completed an 11-item survey with questions related to their past academic experiences, academic plans for the future, and background demographics. All examinees were presented with the race/ethnicity question in two ways. The first was the original question, which allowed respondents to select only one race or ethnicity. The second was the pilot question, which allowed respondents to select all ethnicities and racial groups that were applicable. Based on the responses to the two questions, the test-takers were classified into reference and focal groups in three ways. Comparisons between focal and reference groups were made based on the responses to the original question, the pilot question, and the combined responses to the original and pilot questions. The Mantel-Haenszel D-DIF and standardized P-difference index were used to evaluate differential item functioning. Key findings include: (1) On average, Asian respondents had the highest scores in reading, writing, and math; and (2) Standardized P-difference index seems to be more sensitive than the Mantel-Haenszel D-DIF statistic. Contains a combined bibliography/references list.