Workers’ Compensation (WC) provides medical, disability, rehabilitation or death benefits to employees who have suffered a job-related injury or illness. Employers are generally required by their state’s law to provide WC coverage to employees. Since most employers purchase insurance to satisfy this statutory obligation, it is important to understand how WC insurance premiums are calculated.

The formula for calculating the starting WC premium is (Payroll / 100) x (Premium Rate). To understand this formula we need to discuss three elements that play a big part in calculating the premium.


The premium for WC insurance is based on an employer’s payroll, which is generally defined to include the total remuneration paid by an employer. Payroll typically includes wages, salaries, commissions, bonuses and paid time off, and typically excludes tips, severance, active military duty pay and employee discounts. Employers should check state-specific requirements, including the treatment of executive officers, when calculating payroll for WC insurance purposes.

Classification (Class) Code

Insurance companies use class codes to assign premium rates to specific workplaces based on the risks associated with a particular kind of work. Most states use the classification codes developed by the National Council on Compensation Insurance (NCCI). There are approximately 550 different class codes and they can be very specific. For example, the correct code for Janitorial Services by Contractors may depend on whether the services include window cleaning above ground level.

Though a single employer can be assigned more than one class code, it is important to note that classification codes are designed to categorize employers with common exposures rather than the specific occupations of each employee within an organization. Since class codes are specific and appear to be somewhat conflicting, choosing the appropriate class code is not always easy and mistakes are common.

Premium Rate

Each class code is assigned a premium rate that corresponds to the risks associated with that particular kind of work. These rates, which are evaluated regularly, are applied to every $100 of payroll. Higher risk jobs are given higher premium rates. NCCI provides premium rates for each of its class codes, and many states rely on them when setting their own rates.

Now, let’s assume an employer has a payroll of $187,500 and that the premium rate for its classification code is $1.07. Divide the payroll by 100 [187,500 / 100 = 1,875], and multiply the quotient by the premium rate [1,875 x 1.07] to get a premium of $2,006.25. Note that if the applicable premium rate is $6.05, then the premium would be $11,343.75.

Remember that this is only the starting premium. Additional pricing factors may be applied to the starting premium to arrive at the final premium, such as:

  • Minimum premium requirements
  • Experience modification based on prior loss history
  • Discounts based on the size of the premium
  • Credits for qualifying safety and drug-free programs
  • Dividend plans tied to loss experience
  • Audits adjusting premiums to reflect actual (rather than estimated) payroll

Since the starting premium can be significantly affected by these additional pricing factors, a reputable insurance agent with substantial experience in evaluating and placing WC insurance should be consulted. For those employers with a statutory obligation to provide WC coverage, mistakes can be very costly.

If you would like more information about obtaining workers’ compensation insurance for your organization, please contact us.

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