CAB Report Red Flags for Trucking Insurance Agents: A Visual Walkthrough

A CAB report is a consolidated motor carrier profile sold by Central Analysis Bureau that compiles FMCSA registration, safety, crash, inspection, and authority data into a single document. For trucking insurance agents, it is the working file that turns a raw DOT number into an underwriting picture. This walkthrough goes section by section so you know what each panel is showing you and which patterns are worth a phone call to the insured.

The goal here is interpretation, not panic. CAB data is public-record-derived, and most "red flags" are really just questions that need answers. A well-prepared agent reads the report, drafts the questions, and gets the answers from the carrier before submission. That is the difference between a clean file and a file that gets returned by the underwriter.

What a CAB Report Pulls Together

Before walking through the sections, it helps to know the source data. The FMCSA's Compliance, Safety, Accountability (CSA) program organizes safety data into the seven BASICs (Behavior Analysis and Safety Improvement Categories): Unsafe Driving, Hours-of-Service Compliance, Driver Fitness, Controlled Substances/Alcohol, Vehicle Maintenance, Hazardous Materials Compliance, and Crash Indicator. CAB reports surface these BASICs alongside registration data from MCMIS (Motor Carrier Management Information System) and inspection data from roadside reports. You can read FMCSA's own description of the methodology at https://csa.fmcsa.dot.gov/about/Measure.

A CAB report layers on top of that public data with ISS recommendations, history of authority changes, related-entity links, and graphical trend lines.

Section 1: Carrier Identification Header

The first thing you see is the identification block: legal name, DBA, address, USDOT number, MC number, and entity type (carrier, broker, freight forwarder).

What to read carefully:

• Legal name vs. DBA. A mismatch between the name on the application and the legal name in CAB is not necessarily a problem, but the application should reference both.
• Physical vs. mailing address. A carrier domiciled in one state with a mailing address in a virtual office state can be legitimate, but it is worth a question.
• MCS-150 update date. FMCSA requires a biennial update. A carrier whose MCS-150 has not been touched in over 24 months may have stale mileage and power-unit counts, which throws off utilization factors used by some carriers.
• Power units and drivers. Compare to what the carrier put on the application. A 12-truck carrier that shows 4 power units on MCS-150 needs to explain whether they grew recently or whether the MCS-150 is out of date.

This panel is not an alarm bell. It is the place where you verify the basics match.

Section 2: Operating Authority and Status

Below identification, CAB shows authority status, dates granted, insurance filings on record (BMC-91/91X, BOC-3), and any out-of-service orders.

Patterns to interpret:

Authority history is one of the more useful sections because it gives context. A carrier with three prior DOT numbers under the same officer is a different risk than a single-DOT carrier with two years of clean operation. The Amwins underwriting overview at https://www.amwins.com/resources-and-insights/market-insights/article/cab-usage-in-underwriting-truckers explains why underwriters weigh prior-entity behavior.

Note: not every entity-link is suspicious. Family-owned carriers, growth carriers spinning out a separate brokerage entity, and carriers reorganizing for tax reasons all show up with multiple linked DOT numbers. The job is to ask, not to assume.

Section 3: ISS Score and Recommendation

The Inspection Selection System (ISS) score appears as a number from 1 to 100, paired with one of three recommendations: Inspect, Optional, or Pass.

• 75-100, "Inspect" — FMCSA is recommending roadside inspectors prioritize this carrier.
• 50-74, "Optional" — Discretion of the inspector.
• 1-49, "Pass" — Lower priority for inspection.

Useful context: ISS is calculated from BASIC measures, inspection history, and crash history. A new carrier with little inspection history will often default to "Optional" simply because there is not enough data to score them lower.

What this means for underwriting: a high ISS combined with low inspection counts is a different signal than a high ISS with hundreds of inspections. The first is data scarcity; the second is a pattern. Many MGA submission forms ask the agent to record ISS at submission, so capture it directly from CAB rather than estimating.

Section 4: BASIC Percentile Bars

This is the section that gets the most attention, and the section most often misread. CAB displays each BASIC as a percentile (0-100, where higher is worse) with a status indicator: blank, alert, or above intervention threshold.

The five public BASICs (Unsafe Driving, HOS Compliance, Driver Fitness, Controlled Substances/Alcohol, Vehicle Maintenance) are visible to the public. Crash Indicator and HM Compliance are restricted to the carrier itself and to enforcement.

How to read percentiles correctly:

1. Look at inspection volume first. A carrier with 4 inspections in 24 months and one violation can score in the 90th percentile. That is not the same as a carrier with 200 inspections and a 90th-percentile pattern. Always look at the inspection count next to the percentile.
2. Look at the trend, not just the snapshot. CAB shows historical bars over multiple months. A carrier coming down from the 95th to the 60th percentile is improving. A carrier climbing from the 40th to the 80th is the one worth a question.
3. Check whether the BASIC is "alerted." FMCSA flags BASICs that exceed intervention thresholds. The thresholds differ by BASIC and by carrier type (general, passenger, hazmat). An alerted BASIC is the one that gets enforcement attention and underwriter attention.
4. Read the underlying violations. Two carriers can have the same Vehicle Maintenance percentile, but one might have brake violations clustering and the other might have minor lighting violations. Severity and clustering matter.

The Nelson Insurance overview at https://nelsoninsurancesf.com/csa-scores-cab-alerts-what-they-mean-why-they-matter-and-how-to-fix-them/ walks through how percentile thresholds map to alert status.

Section 5: Inspection History

Below the BASICs, CAB lists inspection records: date, location, level, and outcome. Levels range from Level I (full North American Standard inspection, driver and vehicle) down to Level VI (specialized).

What to look at:

• Out-of-service rate, driver and vehicle. FMCSA publishes national averages annually. A carrier well above the national OOS rate is worth a question, especially if the trend is rising.
• Clean inspections. Clean inspections are positive data points and reduce some BASIC percentiles. A carrier with many clean inspections and a few bad ones often reads better than a carrier with few inspections and one bad one.
• Geographic spread. A regional carrier inspected only in two states is consistent with their operation. A "local" carrier with inspections across ten states deserves a follow-up question about radius of operation.
• Recurring violation types. If "Driver's record of duty status not current" shows up repeatedly across multiple drivers, that is a fleet-level dispatching question, not a one-driver problem.

Most CAB reports let you click into individual inspections. For underwriting, the summary trend matters more than any one report unless that report involved a serious violation.

Section 6: Crash History

Crashes are listed with date, state, fatalities, injuries, tow-aways, and (where available) preventability determination.

A few interpretation notes:

• FMCSA's Crash Indicator BASIC is non-public. You will see the crash list, but the percentile is restricted.
• Preventability is voluntary review. FMCSA's Crash Preventability Determination Program lets carriers request review of certain crashes. A "not preventable" determination removes the crash from the carrier's SMS calculation. CAB usually notes this status.
• Recordable vs. non-recordable. A "DOT-recordable" crash is one with fatality, injury requiring transport from scene, or vehicle requiring tow-away. Not every fender-bender is DOT-recordable.
• Severity and cause matter. A low-speed parking-lot tow-away reads very differently than a fatality on the interstate.

For agents, the question is the same as everywhere else in the report: what is the trend, what is the cause, and what has the carrier done in response? A carrier with one preventability-reviewed crash that came back "not preventable" should not be treated like a carrier with three preventable rear-end events in 18 months.

Section 7: Drivers and Vehicles

CAB lists power units (VIN, year, make, GVW class) and, where available, driver counts and CDL info.

Quick checklist for the equipment list:

1. Match VINs to the application. If the agent's application shows 8 trucks and CAB shows 14, find out which is correct before you submit.
2. Check vehicle age distribution. A fleet of 2008-2012 sleepers is a different physical damage and maintenance risk than a fleet of 2021-2024 trucks.
3. GVW class consistency. A carrier rated as a Class 8 long-haul operation that owns a mix of Class 6 and Class 8 trucks may run mixed operations.
4. Trailer types. Reefer, flatbed, dry van, tanker, and auto-hauler trailers each pull different cargo and liability appetites. Confirm what is actually being hauled.

Vehicle data on MCS-150 is self-reported and updated biennially, so it can lag reality. Always reconcile with the application schedule.

Section 8: Cargo Carried and Operation Type

MCS-150 includes cargo classifications and operation type (interstate/intrastate, hazmat or not, passenger or property). CAB displays these as checked boxes.

Things to verify:

• Hazmat indicator. A carrier hauling hazmat without HM authority on MCS-150 is a paperwork problem worth raising.
• Passenger indicator. Almost always relevant only for motorcoach risks; a property carrier should not have this checked.
• Cargo categories. "General freight" is broad. If the carrier's actual operation is auto transport or household goods, the application should reflect that even if MCS-150 says "general freight."
• Radius of operation. Local (≤100 mi), short-haul, regional, or long-haul. This affects rate and underwriting appetite materially.

Section 9: Insurance Filings History

CAB shows the BMC-91/91X (auto liability), BMC-34 (cargo where filed), and BOC-3 process agent filings, including the carrier(s) that filed them and any cancellations.

Reading insurance history:

• Lapses. A gap between cancellation date and effective date of the next policy is a lapse. Authority is automatically revoked after a 30-day lapse on the BMC-91. A history of lapses is a prior-coverage question.
• Number of carrier changes. Three carriers in two years is worth a question. Sometimes it is a broker shopping aggressively. Sometimes it is non-renewal pattern.
• Cancellation reason codes. Some filings include reason; most do not. Where reason is shown, "non-payment" is different from "agent request."
• Current carrier and effective date. Confirms what the insured is on now.

This section is one of the most underused parts of CAB. A clean insurance filing history with one or two long-tenured carriers reads as stability.

Section 10: Related Entities and Officer Search

CAB cross-references officer names and addresses across DOT records. If the same person appears as an officer on three other carriers, the report will surface those.

This is where chameleon-carrier patterns appear, but it is also where legitimate growth shows up. Examples of patterns and the right question:

Related entities are not an automatic decline. They are an automatic question.

Numbered Checklist: Reading a CAB Report Top-to-Bottom

For agents who want a repeatable process, here is a 10-step walkthrough:

1. Confirm identification matches the application (legal name, DBA, address, DOT, MC).
2. Check authority status and date granted. New venture or seasoned?
3. Read ISS score and recommendation. Capture for submission.
4. Review each BASIC percentile and inspection count behind it. Note any alerted BASICs.
5. Scan inspection history for OOS rate and recurring violation types.
6. Read crash history for severity, frequency, and preventability status.
7. Reconcile power units and drivers between CAB and the application.
8. Verify cargo and operation type match what the insured actually hauls.
9. Review insurance filing history for lapses and carrier turnover.
10. Check related entities and officer history for context.

This is roughly 20-30 minutes per report once you know the layout. New carriers (low data volume) take less; large fleets with long histories take more.

Common Misreadings

A few patterns that look bad but often are not, and a few that look fine but are not:

• High percentile + low inspection count = data scarcity, not necessarily risk. Two inspections, one violation, percentile 95. Get more context.
• Old crash, recent clean record = trend is what matters. A 2021 crash with three years of clean operations since reads differently than a fresh crash.
• Low percentile + low miles = unproven, not safe. A carrier with 12 inspections over 18 months at low mileage has not been tested under load yet.
• Clean BASICs + multiple authority changes = ask about the entity history. Clean current data does not explain why the prior DOT closed.

FAQ

Q: Should I send the CAB report to the underwriter with the submission?

Most MGAs and direct carriers pull their own CAB or have a service that does. Sending yours is rarely required, but capturing the key data points (ISS, alerted BASICs, OOS rate, crash count) on the submission email speeds up the underwriter's read.

Q: How often should I re-pull a CAB report on a renewal?

At minimum, 60-90 days before renewal. Some agents pull at quarterly intervals on larger fleets to track trend changes early.

Q: Is the CAB report the only source I need?

No. SAFER (free, FMCSA), the FMCSA SMS public site, the carrier's own MCS-150 update, and the application from the insured all triangulate. CAB is convenient because it consolidates, not because it is exclusive.

Bottom Line

A CAB report is a working document, not a verdict. Read each section as a question generator: identification, authority, ISS, BASICs, inspections, crashes, equipment, cargo, insurance filings, and related entities. Match what you see against the application. Where they disagree, call the insured before you submit. The agents who do this consistently file cleaner submissions, get fewer underwriter callbacks, and spend less time on rework.

Written by Nazar Mamaev, commercial trucking insurance broker in Indianapolis, IN, and founder of IQS Booster. Published May 2026. Not affiliated with Central Analysis Bureau, FMCSA, Amwins, Nelson Insurance, or any other vendor or publisher referenced in this article. No sponsorship.