Learning Center
Experience Period
The data used to calculate your experience modification is determined by your company's rating effective date (prior to January 1, 2018, known as the anniversary rating date). The inception date, or start date, of your policies determines your company's rating effective date. For example, if your policies always start on January 1, your rating effective date would be January 1. If you have switched inception dates or if you have multiple concurrent policies with varying inception dates, determining your rating effective date may be more complicated. Your insurance professional can help you determine your rating effective date.
Your rating effective date determines the experience period and the effective date of your experience modification. In most cases, all payroll and losses developed under any policy incepting or starting within the experience period are used in determining your experience modification. The experience period begins four years and nine months prior to your rating effective date and terminates one year and nine months prior to the rating effective date. If your rating effective date is January 1, 2023, the experience period is April 1, 2018 to April 1, 2021.
2023 Experience Periods
The below table shows experience periods for rating effective dates throughout 2023.
| Rating Date | Inception Date | Inception Date |
| 01/01/23 | 04/01/18 | 04/01/21 |
| 02/01/23 | 05/01/18 | 05/01/21 |
| 03/01/23 | 06/01/18 | 06/01/21 |
| 04/01/23 | 07/01/18 | 07/01/21 |
| 05/01/23 | 08/01/18 | 08/01/21 |
| 06/01/23 | 09/01/18 | 09/01/21 |
| 07/01/23 | 10/01/18 | 10/01/21 |
| 08/01/23 | 11/01/18 | 11/01/21 |
| 09/01/23 | 12/01/18 | 12/01/21 |
| 10/01/23 | 01/01/19 | 01/01/22 |
| 11/01/23 | 02/01/19 | 02/01/22 |
| 12/01/23 | 03/01/19 | 03/01/22 |
We welcome your feedback on this guide. Please send comments and suggestions to [email protected].