This study used a secondary analysis of the National Assessment of Educational Progress (NAEP) 2003 and 2013 8th grade mathematics scores to explore relationships between parents' education and their eighth-grade students' mathematics achievement. Information from the NAEP database identified parents' educational level and students' eligibility for the National School Lunch Program (NSLP), a proxy measure for SES. A moderate correlation (r = 0.43) was found between parents' educational level and SES. In 2003, the highest average scale score was by students' who were not eligible for NSLP and whose parents' graduated from college (M = 294, SD = 32). The lowest average scale score in 2003 was obtained by students' whose parents' did not finish high school and whose eligibility for NSLP was "unknown" (M = 251, SD = 34). The effect size of the difference between these two groups was large (d = 1.30). Similar results were found in 2013 with overall higher average scale scores.