Rapid proliferation in somatic cells increases mutational burden through replication stress, a consequence that pluripotent cells of the peri-implantation embryo circumvent. In vivo, embryonic cells of a primed pluripotent state proliferate in less than four hours, approximately three times faster than naïve counterparts. We investigated if replication stress management differs in pluripotent cells with inherently different replicative demands. We subjected chimera-generated genetically matched naïve (ESC) and primed epiblast (EpiSC) cells to chemically induced in vitro replication stress. We found that replication stressed EpiSCs, but not ESCs, rely on ATR kinase activity to prevent replication catastrophe, minimize DNA damage, avoid apoptosis, and re-enter the cell cycle. We discovered that heightened stress tolerance in EpiSCs relies on non-canonical nucleotide synthesis mechanisms involving p53R2, an alternate ribonucleotide reductase subunit. We revealed that replication stress management differs across different potency states and specifically that EpiSCs are primed to tolerate replication stress.