MCS-150 mileage vs IRP mileage
MCS-150 mileage is a single annual total reported to FMCSA covering the carrier's entire fleet operations for the prior calendar year. IRP mileage is per-state apportioned mileage reported to the carrier's IRP base state for vehicle-registration apportionment. Both report the same underlying mileage data but at different aggregation levels for different regulatory purposes.
Side-by-side comparison
| Dimension | MCS-150 Mileage | IRP Mileage |
|---|---|---|
| Authority | FMCSA | IRP base state |
| Aggregation | Single annual fleet total | Per-state breakdown |
| Year reported | Most recent complete calendar year | IRP reporting year (typically July 1 - June 30) |
| Use | SMS exposure normalization | Vehicle-registration apportionment |
| Filing schedule | Biennial via §390.19 | Annual via IRP renewal |
| Sub-total relationship | Should approximate sum of IRP states | Sums to MCS-150 total |
MCS-150 mileage in detail
The MCS-150 mileage field captures a single annual total — the carrier's total fleet miles operated on public highways during the most recent complete calendar year. FMCSA uses this number to normalize the carrier's exposure for SMS BASIC scoring; a carrier with 5 million annual miles is compared against carriers with similar exposure rather than against carriers with 50,000 miles. Without the mileage normalization, SMS scores would over-penalize high-mileage carriers and under-penalize low-mileage carriers.
The "most recent complete calendar year" is the key constraint. A carrier filing MCS-150 in March 2026 reports calendar year 2025 mileage; a carrier filing in November 2025 reports calendar year 2024 mileage (because 2025 is not yet complete). The MCS-150 form has a "year" field tied to the mileage entry to make the reporting year explicit.
IRP mileage in detail
The IRP (International Registration Plan) is the multi-state vehicle-registration program that issues apportioned plates authorizing operation across IRP member jurisdictions. IRP requires per-state mileage reporting because the apportionment formula calculates each state's share of registration fees based on the carrier's actual operating mileage in each state. A carrier running 80% of miles in Texas and 20% in Oklahoma owes Texas 80% of the apportioned registration fees and Oklahoma 20%.
IRP mileage reporting runs on the IRP fleet anniversary date with the carrier's base state. The base state collects per-state mileage data for the IRP reporting year (typically July 1 - June 30), calculates apportioned fees, and distributes payments to other IRP member states. The reporting requires per-state granularity because the apportionment math depends on it; a single annual fleet total wouldn't support the calculation.
How the two should reconcile
The MCS-150 single annual total should approximately match the sum of IRP per-state mileage for the corresponding period. The two reporting periods don't exactly align (MCS-150 is calendar year; IRP is typically July-June), so there will be some mismatch, but the magnitudes should be in the same range. Carriers with a 5 million calendar-year MCS-150 mileage should also see roughly 5 million in summed IRP per-state mileage on adjacent IRP renewal cycles.
Significant mismatches between MCS-150 and IRP mileage are an audit risk. FMCSA can cross-reference MCS-150 against IRP data through the federal-state SAFER coordination, and a carrier reporting one number to FMCSA and a meaningfully different number to IRP draws scrutiny. Best practice is to use the same underlying mileage tracking system to populate both — most carriers maintain electronic logs (ELDs) with per-state mileage data that supports both reporting frameworks.
Frequently asked questions
Why does MCS-150 not require per-state mileage?
MCS-150 is a federal carrier-identification form — FMCSA uses the single annual mileage total for SMS scoring exposure normalization, not for state apportionment. Per-state mileage is the IRP system's job; FMCSA does not need that level of detail in MCS-150.
Can I use the same mileage number for both?
Approximately, yes. The MCS-150 single annual total should match the sum of IRP per-state mileage for the same calendar year. Carriers tracking IRP mileage have the underlying data to populate MCS-150; carriers tracking only MCS-150 may need to back-fill per-state data for IRP.
Which year's mileage do I report on MCS-150?
The most recent complete calendar year. A carrier filing MCS-150 in March 2026 reports calendar year 2025 mileage. The MCS-150 form has a "year" field tied to the mileage entry.
Related comparisons
File MCS-150 with current mileage
FastMCS150 collects current calendar-year mileage at intake. Pull the matching number from your ELD or fleet-management system to populate IRP separately.
File MCS-150