Following a traumatic event, many individuals report posttraumatic growth (PTG), meaningful positive changes that emerge from navigating challenging life circumstances. Engaging in adaptive coping and receiving support may facilitate PTG, but the possible temporal dynamics are not well understood (Yu et al., 2017). Our study examined the extent to which adaptive coping behaviors and receipt of instrumental support (e.g., shelter, childcare) predicted PTG from approximately 2–10 months following Hurricane Harvey, which devastated the Galveston-Houston area in 2017. A total of 109 area residents completed two online surveys and residual gain scores and linear regressions were utilized. As expected, T1 hurricane-related trauma symptoms, adaptive coping, and received instrumental support (e.g., transportation, monetary assistance) predicted greater PTG at T2, and T1–T2 reductions in adaptive coping and instrumental support were linked to reductions in PTG (all ps ≤ .05). Thus, PTG may be promoted or impeded by factors soon after the traumatic event as well as changes in those factors over time. Future studies should assess if waning adaptive coping efforts and decreasing received instrumental support stifle long-term PTG and examine individual- and community interventions as countermeasures.