Compared the Marital Interaction Coding System–III (MICS–III) with the revised MICS–IV. An archival data set was used of 994 couples’ videotaped conflict negotiations coded with the MICS. The MICS–IV, relative to the MICS–III, had the advantage of capturing more nonverbal affect expressed during marital interactions, which resulted in stronger interactional contingencies. That is, MICS–IV’s hierarchy rules for creating sequences resulted in more strong negative (i.e., blame) and more subtle positive (i.e., facilitation) codes. MICS–IV rules also resulted in less behavior-laden negative (i.e., invalidation), positive (i.e., validation and propose change), and neutral (i.e., problem description and irrelevant) codes. Furthermore, MICS–IV rules generated significantly lower levels of autodependence than MICS–III.