The purpose of this study was to investigate the impact of a read-aloud test change administered with the Gates-MacGinitie Reading Test (GMRT) on the underlying constructs measured by the Comprehension subtest. The study evaluated the factor structures for the Level 4 Comprehension subtest given to a sample of New Jersey fourth-grade students with and without reading-based learning disabilities. Both exploratory and confirmatory factor analyses were used to determine whether or not the GMRT Comprehension subtest measures the same underlying constructs when administered with and without a read-aloud test change. The results of the analyses indicated factorial invariance held when the Comprehension subtest was administered to groups of students without disabilities who took the test under standard conditions and with a read-aloud test change and for groups of students with reading-based learning disabilities who also took the test under standard conditions and with a read-aloud test change. (Contains 2 figures and 8 tables.)