How is a Montana workers' comp premium calculated?

Premium equals (annual payroll divided by 100) times the class-code manual rate, times your experience modifier. Montana follows the standard NCCI rating method, so the same formula used nationally applies here.

What is an experience modifier?

It is a factor based on your past claims history. A mod of 1.00 is average; below 1.00 means fewer claims than expected (a discount), and above 1.00 means more claims (a surcharge). New employers usually start at 1.00.

Where do I find my class-code rate?

Your insurer or the Montana State Fund assigns each job type an NCCI class code with a manual rate per 100 dollars of payroll. Office work has low rates; roofing or logging are much higher. Check your policy or quote.

Does Montana have a state fund?

Yes. The Montana State Fund is a major workers' comp carrier in the state, alongside private insurers. Rates vary by carrier, so use your specific quoted rate for the most accurate estimate.

Is this the exact price I will pay?

No, it is a budgeting estimate. Final premium can include expense constants, terrorism charges, schedule credits/debits, and audit adjustments based on actual payroll. Use it to plan, not as a binding quote.

Montana Workers' Compensation Premium Calculator

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Workers’ compensation is mandatory for nearly every Montana employer with employees, and the cost is driven almost entirely by two numbers: how risky the work is (your class-code rate) and your past claims record (your experience modifier). This calculator applies Montana’s standard rating formula so you can estimate the annual premium before you request a formal quote from the Montana State Fund or a private carrier.

How it works

Workers’ comp uses a rate per $100 of payroll, not a flat percentage. The core formula is:

Premium = (Annual Payroll / 100) x Manual Rate x Experience Modifier

Payroll is divided by 100 because manual rates are quoted per $100 of remuneration.
Manual rate is the class-code rate your insurer assigns based on the job’s injury risk — office staff might be under $0.30, while construction trades can exceed $10.
Experience modifier scales the premium up or down based on your loss history; 1.00 is neutral.
An optional premium discount (large employers often earn one) is then subtracted.

Tips and example

Suppose you have $200,000 in payroll for a class code rated at $3.50 per $100, with a mod of 0.90. The calculation is (200000 / 100) x 3.50 x 0.90 = $6,300. If your carrier applies a 5% premium discount, your estimate drops to about $5,985.

If you employ workers across several class codes (for example office and field crews), run the calculator once per code and add the results — high-risk payroll dominates the total, so classifying staff correctly matters. Always confirm the final figure with your carrier, as audits reconcile estimated payroll against actual payroll at policy end.