NASA NSSC Publishes Travel Reimbursement Guidance; per diem, ETDY and relocation rules clarified

Observed fact: NASA’s NSSC Travel page (last updated Sep 15, 2026) states the NSSC provides travel reimbursement services for all authorized Agency travel, including domestic, foreign, local, Extended Temporary Duty (ETDY) and Change of Station (COS).

Source claim: NASA specifies per-diem and lodging rules. For domestic travel, the page says the per diem for the day travel ends is 75 percent of M&IE; for ETDY the standard reduced per diem is 65 percent and that reduced rate begins on the first day of travel unless otherwise noted.

Source claim: NASA directs travelers to use long-term lodging options for ETDY longer than 90 days; it also references GSA Schedule 48 for lodging solutions designed for stays of 30 days or more.

Source claim: The NSSC page lists Change of Station processing steps, a long list of COS forms (for example, NF1500, NF1810, NF1811, NF1812, NF1813 and SF 1038) and links to relocation tax guidance and related references.

Source claim: Practical rules called out include: rental-car charges are payable only for official travel time and travelers bear rental costs attributable to annual leave; POV mileage reimbursement refers users to the GSA mileage rates; and state tax exemption status should be checked through the GSA SmartPay tax pages.

Practical consequence: Travelers and managers should expect lower daily reimbursement for ETDY and for travel-end days than for full TDY days; these reductions can materially change travel budgets and housing choices, especially for prolonged assignments.

Practical consequence: For relocations and ETDY over several weeks, managers should evaluate GSA long-term lodging options first; selecting contract long-term housing can keep costs within the reduced per-diem framework and allow use of the government charge card.

What is not yet known: The page summarizes policy and links to regulations and forms; it does not publish the specific M&IE dollar amounts, state-by-state tax-exemption forms, or the full list of expenses included under the ETDY reduced rate on the page itself. Those details live in the cited CFR, NASA Procedural Requirements and linked documents.

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