Traveling tradespeople - pipeline welders, millwrights, boilermakers, turnaround crews, and industrial electricians - often use per diem, mileage, and mob/demob rows to discuss the real cost of living away from home. The General Services Administration publishes federal CONUS per diem rates, and IRS guidance explains travel-expense and reimbursement context, but neither source automatically decides a private employer package.
Getting per diem right requires source checks. Current fiscal year, work location, lodging locality, employer policy, union or CBA terms, accountable-plan facts, tax home, assignment length, payroll setup, and qualified review can change the answer. This guide explains what to look up and what the ToolGrit screen can and cannot resolve.
How GSA Per Diem Rates Work
GSA per diem has two main components: lodging and Meals & Incidental Expenses (M&IE). Lodging is locality and month specific. For FY2026 CONUS M&IE, GSA lists five rows: $68, $74, $80, $86, and $92. The ToolGrit app caches those M&IE rows, but it does not perform a live city, ZIP, county, work-location, month, or fiscal-year lookup.
The M&IE breakdown allocates specific amounts to breakfast, lunch, dinner, and incidentals. For the $68 row: breakfast $16, lunch $19, dinner $28, incidentals $5. For the $92 row: breakfast $23, lunch $26, dinner $38, incidentals $5. These rows are useful for screening furnished-meal deductions, but employer policy and project facts can change treatment.
Rates are published by fiscal year and must be verified in the current GSA lookup for the work location. Adjacent counties, lodging locality exceptions, seasonal lodging, and non-CONUS travel can change the applicable row.
Per Diem & Travel Pay Calculator
Calculate per diem, lodging, mileage, and mobilization costs with GSA rate tiers, first/last day 75% rule, meal deductions, and IRS mileage rates. Includes rate lookup guidance.
The 75% First and Last Day Rule
The GSA CONUS M&IE table lists first and last travel-day amounts equal to 75% of each M&IE row. For example, the FY2026 $68 row has a $51 first/last day amount, and the $92 row has a $69 first/last day amount. The app applies this arithmetic prompt to the selected row.
Lodging is normally handled separately because it depends on actual nights, locality, receipts, taxes, and policy. A 5-day trip can be screened as 3 full M&IE days, 2 first/last day rows, and 4 lodging nights, but the final reimbursement or billing treatment depends on the controlling policy or contract.
Long-term assignment treatment can depend on temporary-assignment facts, tax home, return trips, employer policy, and CBA language. Treat the 75% row as a calculation prompt, not as a payroll or tax conclusion.
Taxable vs. Non-Taxable Per Diem
Taxable versus non-taxable per diem depends on facts and current IRS guidance, including tax home, temporary assignment, business connection, substantiation, return of excess amounts, and W-2 treatment. The app can flag a review prompt when a manual M&IE row exceeds the standard CONUS row, but it does not decide tax status.
The tax-home question is a common source gap for traveling trades. Permanent residence, recurring work area, duplicate living expenses, assignment length, and documentation can all matter. Workers and employers should review Publication 463 and qualified tax or payroll support before relying on any treatment.
Amounts above the applicable federal rate can create payroll and tax questions, but the applicable federal rate may be different from the standard row by locality and date. Treat any excess estimate as a review prompt for payroll or tax professionals.
Where to Look Up Current Rates
The primary source is the GSA per diem lookup, which searches by city, state, or ZIP code and organizes rates by federal fiscal year. Verify the rate for the travel month and work location, not only a nearby hotel or a remembered annual default.
For Alaska, Hawaii, territories, and foreign travel, different federal sources and rate schedules may apply. The ToolGrit screen is limited to cached CONUS M&IE rows and manual lodging input.
Payroll and contractor management systems may include GSA lookups, but the setup still needs review. Import dates, fiscal-year changes, work-location mapping, project contract clauses, and override rows can all create mistakes.
Negotiating Per Diem Packages
For craft workers, per diem can be a major part of the total travel package, alongside hourly rate, mobilization, demobilization, mileage, airfare, and R&R rotations. A useful negotiation starts by separating the arithmetic from the source gaps: current locality rates, employer policy, CBA language, receipts, tax treatment, and payroll setup.
Manual rates above a federal locality row should be reviewed before assuming they are taxable, non-taxable, owed, excluded, or included in another wage calculation. The answer depends on the controlling agreement and tax/payroll facts.
For employers, structured travel packages can help recruit specialized crews, but source review matters. Actual-expense reimbursement, flat per diem, mobilization pay, airfare, project lodging, and certified payroll can each have different documentation and compliance requirements.