Travel Per Diem

GrantKit automatically calculates travel costs using official GSA (General Services Administration) per diem rates.

Why Use GSA Rates?¶

Federal grants require travel costs to follow GSA guidelines:

• Lodging: Maximum reimbursable hotel rates by location

• M&IE: Meals and Incidental Expenses daily allowance

• First/Last Day: 75% of M&IE rate

Using GSA rates ensures your budget is defensible and compliant.

Configuration¶

In your budget.yaml:

travel:
  - description: "Annual conference (AAAS)"
    destination: "Washington, DC"
    travelers: 2
    days: 4
    per_year: 1

  - description: "Collaborator visit"
    destination: "Boston, MA"
    travelers: 1
    days: 3
    per_year: 2

  - description: "NSF project meeting"
    destination: "Alexandria, VA"
    travelers: 3
    days: 2
    per_year: 1

Automatic rate lookup¶

Travel is costed through the budget engine (grantkit.budget.BudgetManager), which grantkit check uses for arithmetic. GSA rate lookups make network calls, so they run only when a GSA_API_KEY is set; otherwise the manager falls back to the lodging_rate / mie_rate you provide (or conservative defaults). When enabled, GrantKit:

1. Looks up GSA rates for each destination

2. Calculates lodging, M&IE, and first/last day adjustments

3. Adds your airfare estimates

4. Produces an itemized travel budget

Example Output¶

Travel Budget - Year 1
======================

1. Annual conference (AAAS) - Washington, DC
   Travelers: 2, Days: 4

   Per person:
     Airfare (estimated): $450
     Lodging: 3 nights × $258 = $774
     M&IE: 2 full days × $79 = $158
     M&IE: 2 partial days × $59 = $118
     Subtotal: $1,500

   Total (2 travelers): $3,000

2. Collaborator visit - Boston, MA
   ...

Year 1 Travel Total: $8,450

GSA Rate Sources¶

GrantKit fetches rates from:

• CONUS: https://www.gsa.gov/travel/plan-book/per-diem-rates

• OCONUS: https://aoprals.state.gov/web920/per_diem.asp

Rates are cached locally and updated when the fiscal year changes (October 1).

Manual Override¶

You can specify custom rates if needed:

travel:
  - description: "International conference"
    destination: "London, UK"
    travelers: 1
    days: 5
    lodging_rate: 350  # Override GSA
    mie_rate: 120
    airfare: 1200

Fiscal Year¶

GSA rates change on October 1. GrantKit uses the appropriate fiscal year based on your project start date:

project:
  start_date: "2025-09-01"  # Uses FY2025 rates

Programmatic usage¶

from grantkit.budget import GSAPerDiemAPI

api = GSAPerDiemAPI()  # reads GSA_API_KEY from the environment
lodging, mie = api.get_rates("Washington", "DC", fiscal_year=2025)
print(f"Lodging: ${lodging}  M&IE: ${mie}")

BudgetManager.load_from_yaml(...) then calculate_totals() applies these rates across every travel line item and returns a full budget summary.