Innate immune memory is the process by which pathogen exposure elicits cell-intrinsic states to alter the strength of future immune challenges. Such altered memory states drive monocyte dysregulation during sepsis, promoting pathogenic behavior characterized by pro-inflammatory, immunosuppressive gene expression and emergency hematopoiesis. Epigenetic changes, notably via histone modifications, have been shown to underlie innate immune memory, but the contribution of DNA methylation remains poorly understood. Using an ex vivo sepsis model, we discovered broad changes in DNA methylation throughout the genome of exhausted monocytes, including at several genes implicated in immune dysregulation during sepsis and Covid-19 infection (e.g. Plac8). Methylome reprogramming is driven in part by Wnt signaling inhibition in exhausted monocytes, and can be reversed with DNA methyltransferase inhibitors, Wnt agonists, or immune training molecules. These changes are recapitulated in septic mice following cecal slurry injection, supporting the involvement of DNA methylation in acute and long-term monocyte dysregulation during sepsis. Overall design: Genome-wide DNA methylation profiling was performed using Infinium Mouse Methylation BeadChip arrays. Based on variability observed in previous studies, a minimum of 4 biological replicates was determined to be sufficient for most BMMC culture experiments. To account for greater mouse-to-mouse variability in response to in vivo cecal slurry injections, a minimum of 6 biological replicates was collected for control and experimental day 7 mice. From discussions with the sesame analysis pipeline author, it was determined that n = 3 and n = 4 was sufficiently powered to detect differences in 5mC as low as 5% for BMMC culture and in vivo bone marrow monocytes, respectively. All experiments were performed on at least two separate days and with mice from at least 3 separate litters. For in vivo cecal slurry experiments, mice were randomly split between cecal slurry injection and PBS control injection groups by researchers uninvolved with downstream analyses.