Posttraumatic stress disorder (PTSD) is linked with impaired intimate relationships in postpartum women, yet less is known about couple-level manifestations of posttraumatic psychopathology and potential associations with relationship functioning for mothers and fathers during this critical time. In a predominately low-to-middle income sample of 867 mother-father couple dyads assessed six months following the birth of a child, two analytic methods-a data-driven dyadic latent profile analysis and hypothesis-driven categorization approach-evaluated whether discrete subgroups of couples could be identified based on both partners' PTSD symptoms. Structural equation models then tested associations between identified subgroups with (1) self-reported relationship quality and (2) interviewer-rated relationship stress. Three couple-level PTSD symptom groupings were common to both methods: , , and . Dyad-level PTSD symptom patterns were differentially related to relationship dysfunction for mothers and fathers, although mixed findings emerged across methods regarding the relevance of which partner had elevated symptoms for relationship functioning in PTSD symptom-discordant couples. Individuals in dyads characterized by at least one partner with elevated PTSD symptoms consistently exhibited greater relationship dysfunction-indexed both subjectively and objectively-compared to dyads where both partners had low symptoms. Couple-level typologies of PTSD symptoms can be identified using data- and hypothesis-driven approaches, with generally concordant results. Dyadic patterns of PTSD symptoms are relevant to relationship functioning for both mothers and fathers during the postpartum period and may help to inform more targeted intervention efforts to support couples who are parenting.