The reading portion of the Michigan Educational Assessment Program (MEAP) was equated to the reading comprehension subtest of the Comprehensive Tests of Basic Skills (CTBS) using the Rasch Model. Both tests were administered to 366 low achieving fourth grade students. MEAP was treated as both a 95-item test and a 19-item (number of objectives attained) test. Linking constants were established by single, pairwise, and independent calibrations, as a basis for converting MEAP(95) and MEAP(19) to CTBS national percentiles. Rasch item difficulty estimates were applied to compare the tests' difficulties and to define minimal competency levels. Results indicated that the content of MEAP(19) was not reliably linked to either the CTBS or the MEAP(95), although the 19 MEAP objectives completely overlapped the CTBS. Items from tests as different in difficulty as MEAP and CTBS were successfully linked, although objective mastery was not as amenable to this procedure. (CP)