- Workers' compensation insurance
- Insurance that pays medical care and lost wages for employees injured or made ill on the job, and generally protects the employer from lawsuits over those injuries. Nearly every state requires employers with employees to carry it; rules on owners, small employers and exemptions vary by state.
- Class code and rate
- Each type of work is assigned a class code with a rate per $100 of payroll that reflects its injury risk — clerical work has a low rate, roofing a very high one. The rates come from your carrier and state rating bureau and change yearly.
- Manual premium
- Payroll divided by 100, times the class rate, added up across your class codes. $500,000 of payroll at $1.50 per $100 is a $7,500 manual premium before any adjustments.
- Experience modification factor (EMR)
- A multiplier based on your own claims history compared with similar businesses, usually over three years. A 0.85 mod cuts the premium by 15%; a 1.25 mod raises it by 25%. It is calculated by NCCI or your state bureau once a business is large enough to qualify.
- Schedule rating
- Credits or debits an underwriter may apply for things not reflected in your mod, such as safety programs, workplace condition or employee training. States limit how large they can be.
- Standard premium and premium discount
- Standard premium is the manual premium after the experience mod and schedule rating. Larger policies may then get a premium discount that reflects lower administrative cost per dollar of premium.
- Payroll audit
- Workers' comp is priced on estimated payroll, then audited after the policy year. If actual payroll was higher, you owe more premium; if lower, you get a refund. Keeping employees in the correct class codes avoids surprises.