Skip to content

Kuespert Insurance Agency Blog

All You Ever Wanted to Know About Insurance

Cracking the Code: How Are Workers' Compensation Premiums Calculated?

Cracking the Code: How Are Workers' Compensation Premiums Calculated?

Workers' compensation insurance is a crucial component of protecting both employees and employers in the event of workplace injuries or illnesses. For businesses, understanding how workers' compensation premiums are calculated is essential for budgeting and ensuring compliance with legal requirements. In this blog, we'll delve into the intricacies of workers' compensation premium calculations to shed light on this vital aspect of business insurance.

The Basics of Workers' Compensation Insurance

Workers' compensation insurance is a state-mandated insurance program that provides benefits to employees who suffer work-related injuries or illnesses. It offers financial support for medical expenses, rehabilitation, and a portion of lost wages. Employers are required to carry workers' compensation insurance to provide this protection to their employees.

Key Factors Influencing Premium Calculations

The calculation of workers' compensation premiums is a complex process that takes into account several key factors:

  • Classification Code: Each occupation is assigned a classification code based on the level of risk associated with the job. The National Council on Compensation Insurance (NCCI) or a state-specific rating bureau determines these codes. The higher the risk, the higher the premium for that occupation.
  • Payroll: The size of your company's payroll is a significant factor in premium calculations. Premiums are typically based on the total payroll for all employees in the covered job classifications.
  • Experience Modification Factor (Mod): This factor reflects your company's claims history. If your business has a history of frequent and costly workers' compensation claims, your Mod factor will increase, leading to higher premiums. Conversely, a good safety record can lead to lower premiums.
  • Location: The state in which your business operates also affects your workers' compensation premiums. Each state sets its own workers' compensation regulations and rates, leading to varying premium costs.
  • Annual Premiums: Workers' compensation premiums are calculated annually. Your business's actual payroll data for the previous policy period is used to determine the final premium.
  • Manual Premium: The manual premium is calculated by multiplying the payroll for each job classification by the rate assigned to that classification.

Understanding the Experience Modification Factor (Mod)

The experience modification factor (Mod) is a crucial element in workers' compensation premium calculations. It's a numerical representation of your company's claims history and safety performance. The Mod factor compares your company's actual losses to the expected losses for a business of similar size and industry. Here's how it works:

  • Mod Factor Below 1.0: A Mod factor below 1.0 indicates that your company's losses are lower than expected for your industry, resulting in lower premiums.
  • Mod Factor Above 1.0: A Mod factor above 1.0 suggests that your losses are higher than expected, leading to higher premiums.
  • Mod Factor of 1.0: A Mod factor of 1.0 means your company's losses are in line with industry expectations, resulting in standard premiums.

Steps to Manage Workers' Compensation Premiums

  • Safety Programs: Implement robust safety programs to reduce workplace injuries and illnesses, which can positively impact your Mod factor and lower premiums.
  • Claims Management: Actively manage and control workers' compensation claims to minimize their impact on your Mod factor.
  • Accurate Classification: Ensure that your employees are accurately classified based on their job duties. Misclassification can lead to incorrect premium calculations.
  • Regular Audits: Regularly review your workers' compensation policy and payroll data to ensure accuracy and make necessary adjustments.
  • Insurance Advisor: Work with an insurance advisor or broker who specializes in workers' compensation to navigate the complexities of the system.


Workers' compensation premiums are calculated based on various factors, including classification codes, payroll, experience modification factors, and location. Understanding how these factors interact and impact your premiums is essential for businesses to effectively manage their workers' compensation insurance costs. By implementing safety measures, managing claims, and maintaining an accurate record, businesses can work towards reducing their premiums and ensuring the well-being of their employees.