> ## Documentation Index
> Fetch the complete documentation index at: https://docs.taxhomebase.com/llms.txt
> Use this file to discover all available pages before exploring further.

# GSA Per Diem

> How TaxHomeBase compares your stipends against IRS per diem limits.

GSA per diem rates are the IRS benchmark for tax-free stipend amounts. TaxHomeBase automatically compares your assignment stipends against these limits and flags any excess.

For background on what GSA rates are and why they matter, see [GSA Rates Explained](/tax-education/gsa-rates-explained).

## How the Comparison Works

For each assignment, TaxHomeBase:

1. **Looks up the GSA rate** for the assignment's state and location
2. **Converts your weekly stipend** to a daily rate (÷ 7)
3. **Compares housing and M\&IE separately** against GSA lodging and M\&IE limits
4. **Determines if you're within limits** — both must be at or below the GSA rate

## Rate Lookup

TaxHomeBase uses a two-tier lookup:

1. **Live GSA API** — Fetches current rates from `api.gsa.gov` (24-hour cache)
2. **Static fallback** — Keyword-matched rates for \~50 top travel nurse metro areas plus the CONUS default

The static fallback ensures the feature works even without a GSA API key or when the API is unavailable.

## Where It Appears

<Frame caption="Assignment cards show GSA compliance badges and expanded detail shows daily rate comparisons.">
  <img src="https://mintcdn.com/stipendguard/rYTODjwsgR5TPzB9/images/guides/assignments.png?fit=max&auto=format&n=rYTODjwsgR5TPzB9&q=85&s=523a0a03caa2cea3a21a0ff475e6b6e8" alt="Assignments page showing GSA compliance badges on assignment cards" style={{ maxWidth: '300px' }} width="786" height="3430" data-path="images/guides/assignments.png" />
</Frame>

### Assignment Cards

* **Badge on card header** — Green "Within GSA limits" or amber "Exceeds GSA limits"
* **Expanded detail** — GSA Per Diem Comparison grid:
  * Your daily housing rate vs. IRS max
  * Your daily M\&IE rate vs. IRS max
  * Excess amount (if any)
  * First/last day 75% M\&IE note

### Tax Estimate

Each assignment in the estimate includes a `gsa` object with:

* GSA lodging and M\&IE rates for the area
* Your daily housing and M\&IE rates
* Housing and M\&IE excess amounts
* `withinLimits` boolean
* Area name

### Notifications

A `gsa_exceeds` alert aggregates all exceeding assignments into one notification with the total excess amount.

### Export

The PDF includes a **GSA Per Diem Compliance** table with per-assignment details:

* Facility and location
* GSA area name
* Daily rate comparison (yours vs. GSA)
* Status (within/exceeds)

The Audit Defense Checklist includes a GSA compliance item (green if all within limits, amber with count if exceeding).

## First and Last Day Rule

GSA rules specify that M\&IE is **75% of the full rate** on the first and last day of travel. TaxHomeBase calculates and displays this adjusted rate.

## What to Do If You Exceed

Exceeding GSA rates doesn't automatically make your stipends taxable, but it increases IRS scrutiny:

1. **Talk to your agency** — Ask if they can restructure the pay package
2. **Document the actual costs** — If local housing truly costs more than the GSA rate, receipts help justify the higher stipend
3. **Consult your CPA** — They can advise on reporting the excess properly