Technical Note The Occupational Requirements Survey (ORS) provides job-related information about the physical demands; environmental conditions; education, training, and experience; as well as cognitive and mental requirements in the U.S. economy. Additional job requirement estimates are available at www.bls.gov/ors/data.htm. For information on estimation concepts and methods see the ORS website at www.bls.gov/ors and the Handbook of Methods at www.bls.gov/opub/hom/ors/home.htm. Sample size: The ORS is a nationally representative establishment-based survey. Estimates are produced from a probability sample of 28,900 establishments. There were 14,500 private industry and 3,000 state and local government responding establishments that provided approximately 84,800 occupational observations. The 2021 estimates represent 135,979,200 civilian workers. These estimates are from three of five samples and are considered preliminary. Data from all five samples collected between September 2018 and July 2023 will be aggregated to produce the final estimates with an expected reference year of 2023. Standard errors: Standard errors provide users a measure of the precision of an estimate to ensure that it is within an acceptable range for their intended purpose. Collected and imputed data are included in the standard error calculation. For further information and how to use the standard errors see www.bls.gov/ors/se.htm. Major terms: Critical job function - This is the main purpose and the primary pay factor for the job. It consists of critical tasks that are integral to the job. Critical tasks - Activities workers must perform to carry out their critical job function(s). Choice of low posture – Ability to select low posture to perform critical tasks. Workers may be required to perform some critical tasks in a specific low posture and other critical tasks may allow for choice in low postures. Choice of sitting or standing – The ability to alternate between positions. Three conditions must exist: (1) workers typically have the flexibility to choose between sitting and standing throughout the workday; (2) there are no assigned periods during the workday to sit or stand; and (3) no external factors determine whether workers must sit or stand. Hazardous contaminants – Exposure to substances that have a negative impact on the respiratory system, eyes, skin, or other living tissue. Biohazards such as blood or other bodily fluids are not considered hazardous contaminants. Telework – Ability to perform the critical job function off work premises, typically from home. Workers must have a formal arrangement with the employer and telework must be available to all workers in the job. Temporary or ad hoc telework arrangements, such as those made in response to the Coronavirus pandemic, are not included.