actual and necessary subsistence
actual and necessary subsistenceA National Institutes of Health (NIH) phrase that provides the language for reimbursing travellers for their actual costs when their expenses are unusually high due to special or unusual circumstances.
Reimbursement is not to exceed 150% of the General Services Administration (GSA) rate for the area. Subsistence generally includes items such as lodging and meals. Advance approval prior to travel is required.