There is an urgent need to develop quantifiable biomarkers for acute sleep loss, chronic sleep insufficiency, circadian disruption and sleep disorders such as obstructive sleep apnea. These problems are highly prevalent but currently we do not have biomarkers to use for case identification, prognosis, or assessing response to therapy. There are currently small studies that indicate the feasibility. A recent workshop in biomarkers was held at NIH. This was jointly organized by the National Center for Sleep Disorders Research and the Sleep Research Society.