Medulloblastoma patients were stratified into average-risk and high-risk treatment groups based on metastatic status and extent of resection as part of SJMB03. Medulloblastomas were molecularly classified into subgroups (Wingless [WNT], Sonic Hedgehog [SHH], group 3, and group 4) and subtypes based on DNA methylation profiles and overlaid with gene mutations from next-generation sequencing. Clinical and molecular risk factors were evaluated and used to model new risk-classification categories. The results below are arrayed by subgroup with age, sex and metadata provided. Chromosomal abnormalities (gains or losses) are displayed by arm and genetic alterations by selected frequently observed genes. The patterns observed will be used to stratify risk for future patients.