Superfund practitioners are waiting to see whether the U.S. Environmental Protection Agency (EPA) will designate perfluorooctanoic acid and perfluorooctane sulfonate, two chemicals in the per- and polyfluoroalkyl substances (PFAS) group, as CERCLA hazardous substances. Such a designation may lead to selected remedies being modified and further work being required at Superfund sites where remedies were believed to be complete. This Article explores potential future liability by reviewing provisions of the 2021 Remedial Design/Remedial Action (RD/RA) Model Consent Decree. It helps potentially responsible parties (PRPs) that have entered into RD/RA consent decrees understand what their future liability may be, and offers advice for PRPs that are considering entering into RD/RA consent decrees so that they can achieve the most upfront certainty and resolve possible.