The Miranda Rights Comprehension Instruments (MRCI) constitute a revision of Grisso’s Instruments for Assessing Understanding and Appreciation of Miranda Rights (IAUAMR) original series of tests. We believe that the MRCI represents an improvement in many respects, including (but not limited to) a thorough discussion of admissibility issues in the test manual, simplification of language, the addition of a fifth warning, and updated normative data. We also review some potential challenges associated with the revised MRCI tests. These concerns include inconsistent and confusing terminology in the test manual, potentially nonrepresentative normative data, problematic reliability estimates, issues with scoring criteria for the CMR-II, item and test content representativeness for specific tests, and recommendations on how test effort and malingering should be assessed via the CMR-R-II. We conclude with a series of recommendations for forensic use of the MRCI.