Despite innovative policy and pedagogical transformations, postsecondary achievement gaps continue to exist between African American males and other students. Low college credential completion rates by African American males have prevented an East Texas community college from meaningful participation in the President's 2020 postsecondary education attainment goal of increasing U.S. college graduates by 5 million. The purpose of this quantitative study was to investigate a hypothesized connection between the independent variable, mode of instruction, and the dependent variables, mathematics course completion and college completion by African American males. Guided by Ogbu's cultural-ecological theory of minority school performance, a chi-square test of independence was used to compare 407 African American males who participated in the mode of lecture and 412 who participated in modular instruction. Findings included a significant relationship (p <.05) between mode of instruction and developmental mathematics completion (p = .000) with the lecture mode associated with higher achievement. No significant relationship existed between instructional mode and college credential completion (p = .503). These findings called the effectiveness of modular instruction into question and indicated that, at this research site, the instructional mode in developmental mathematics is insufficient to address the disparity in college completion rates of African American males. These results informed a policy recommendation paper, written to help local college administrators better understand African American male remedial math and college credential completion rates. This study contributes to positive social change by generating data-based local institutional policies that will promote African American male postsecondary achievement.