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How to Check the Insurer's A.M. Best Rating on a Certificate of Insurance
A certificate can show every limit and endorsement you asked for and still have a weak spot: the insurance company behind it. If the insurer can't pay claims, the coverage on paper doesn't help much. That's why many subcontracts and vendor agreements include a minimum insurer rating, most often from A.M. Best.
What an A.M. Best rating is
A.M. Best is a credit rating agency that focuses on insurance companies. Its Financial Strength Rating is an opinion of an insurer's ability to pay claims. The scale runs from A++ and A+ (Superior) through A and A- (Excellent), B++ and B+ (Good), and down from there. A separate Financial Size Category, written as a Roman numeral from I to XV, reflects the size of the insurer's capital and surplus.
A common contract clause reads something like "insurers rated A- VII or better by A.M. Best." That means a rating of at least A- and a size category of at least VII.
Finding the insurer on the ACORD 25
- Look at the Insurers affording coverage section, lettered A through F, near the top of the form.
- Each insurer has a name and an NAIC number, a unique code assigned by the National Association of Insurance Commissioners.
- Match the letters in the INSR LTR column of the coverage table to see which insurer writes each policy. GL, auto, workers' comp, and umbrella are often with different companies.
Use the full legal name and NAIC number, not the agency or the brand name. Insurance groups often have several companies with similar names and different ratings.
Looking up the rating
A.M. Best publishes ratings on its website with a search by company name. Search for the exact company listed, and check the rating for that specific company, not just its group. If the rating is under review or has been downgraded, note it.
You can also look up the NAIC number on your state insurance department's site or the NAIC's company search to confirm the company exists and see where it's licensed. A certificate listing an insurer you can't find at all is a red flag; see our guide to spotting a fake certificate.
When the insurer doesn't meet your requirement
- Check the contract language first. Some clauses allow exceptions with your written approval, or only apply to certain policies.
- Ask the agent. Sometimes the sub has another option, or the agent can explain why the carrier was used.
- Decide and document. If you accept a lower-rated insurer, record who approved it and why. If you don't, treat it like any other deficiency and hold new work until it's fixed.
- Recheck at renewal. Subs switch carriers at renewal more often than you'd think, so the rating check isn't one-and-done.
Insurers that aren't licensed in your state (surplus lines carriers) raise a related question; see our guide to non-admitted insurers on a COI.
Key takeaways
Find each insurer by letter and NAIC number, look up that exact company's rating, compare it to your contract, and recheck when policies renew. SubCover HQ checks insurer details along with limits, endorsements, and dates on every certificate it reviews, for $99/month.
Frequently asked questions
What does A- VII mean in an insurance requirement?
An A.M. Best Financial Strength Rating of at least A- (Excellent) and a Financial Size Category of at least VII.
Where is the insurer listed on an ACORD 25?
In the Insurers Affording Coverage section, lettered A through F, each with an NAIC number. The INSR LTR column shows which insurer writes each policy.
What if a sub's insurer is rated below my requirement?
Check whether your contract allows exceptions, ask the agent about alternatives, and either document an approved exception or treat it as a deficiency.
This guide is general information, not insurance or legal advice. Your contracts and insurance professional determine what you should require.
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