Biomarkers have been fundamental to progress is many fields of medicine, and the paucity of biomarkers of traumatic brain injury are a barrier to progress in the field. Recently, several analytical assays for proteins found in blood have been cleared for use by the US Food and Drug Administration and the European Commission as adjuncts in the assessment of TBI, and others are in the horizon. This session will review the state of the science of TBI biomarkers, discuss current barriers to further adoption, and highlight contexts-of-use where biomarkers are anticipated to impact brain injury medicine.