Author, Drew Garcia, NALP Program Director, Rancho Mesa Insurance Services, Inc. 

The Experience Modifier (i.e., experience MOD, MOD, XMOD, experience modification rating, EMR) weighs heavy on the calculation of your workers' compensation premium. With a MOD rating of 1.00 signifying unity  (i.e., the average for your industry), any MOD above 1.00 is considered adverse. Thus, any MOD below 1.00 is considered better than average. Higher MODs will debit the premium, resulting in higher workers' compensation premiums, while lower MODs will credit the premium, resulting in lower workers' compensation premiums.