The practical answer
The Experience Modification Rate is a multiplier applied to your workers' compensation premium, and it has become the single most-used gate in contractor prequalification — often more decisive than TRIR, because it comes from an insurer rather than from you.
It is not calculated by you, cannot be edited by you, and is issued on a letter you request from your carrier or rating bureau.
What the number means
EMR compares your actual workers' comp loss history against the expected losses for a business of your size and classification. 1.0 is the benchmark — you performed as expected.
Below 1.0 means fewer or cheaper claims than expected, and your premium is discounted accordingly. Above 1.0 means worse than expected, and the premium rises. An EMR of 0.85 means a 15% credit; 1.20 means a 20% surcharge on the same coverage.
Who issues it
Not you and not the client. In most states NCCI (the National Council on Compensation Insurance) produces the rating; several states run their own bureaus — California through WCIRB, and others including Pennsylvania, Delaware, Michigan, Minnesota, New Jersey, New York, North Carolina, Texas and Wisconsin operate independently.
Contractors obtain an EMR letter from their carrier or agent. Because it is third-party issued, clients treat it as harder evidence than self-reported statistics — which is exactly why it is the most common hard cap in prequalification.
Why 1.0 is the cutoff everyone quotes
Many owner-clients set the bid gate at or below 1.0 for no deeper reason than that it is the definitional average — it is a legible line, not a safety threshold. Some accept higher with a written corrective action plan; some in high-hazard work set it lower.
The practical consequence for a contractor is severe: an EMR above the cap can remove you from bid lists entirely, regardless of how good your current program is.
It moves slowly, which cuts both ways
EMR is computed on a multi-year experience window that excludes the most recent policy year, so a claim affects your rating for years after it closes, and improvements take years to appear. There is no fast fix.
That lag is worth stating plainly to anyone treating EMR as a current safety measure: it describes a window that ended before the present one began. It is a strong signal precisely because it cannot be improved quickly — and a weak one for judging what a crew is doing this month.
Verifying it on the collecting side
If you are gating subcontractors on EMR, the letter is the artifact — a figure typed into a form is not evidence, and the letter carries the issuing bureau, the rating effective date, and the entity name that must match your contract. Rating dates matter: an EMR letter from two cycles ago is not the current rating.
CoverWarden checks the uploaded EMR letter against the cap you set and flags stale rating dates alongside the rest of the prequalification packet.
Keep coverage decisions human and evidence explicit
CoverWarden records submitted evidence, requirements, findings, and authorized decisions. It does not issue coverage, guarantee claim outcomes, or replace your broker, attorney, or risk professional.
What teams usually ask
What is a good EMR for a contractor?
Below 1.0 means better-than-expected loss history. Many clients set 1.0 as the bid gate, though thresholds vary and some accept higher with a corrective action plan.
Who calculates EMR?
NCCI in most states; independent bureaus elsewhere, including WCIRB in California. Never the contractor or the hiring client.
How fast can EMR be improved?
Slowly. It uses a multi-year window that excludes the most recent policy year, so improvements take years to appear.
Is EMR the same as TRIR?
No. EMR is an insurance premium multiplier from claim costs; TRIR is an injury frequency rate from your OSHA log.