(a) Change in DIB O/M. The amount of the worker's compensation or public disability benefit reduction does not change when there is an increase in the DIB O/M rate because of an amendment or cost of living increase. However, the reduction amount does change if there is a change in the family members included in the DIB O/M. When the number of family members changes and the DIB O/M is still payable, the amount of the reduction is recomputed using the DIB O/M rate, including the changed family group, as if the new family composition had existed when the worker's compensation or public disability benefit reduction first applied. However, this new reduction is not effective until the date of the change of the family group. The worker's compensation or public disability benefit and average current earnings are the same as those used before the change in the family group.

(b) Change in amount of worker's compensation/public disability benefit. The amount of the reduction for worker's compensation or public disability benefit changes when there is a change in the amount of the worker's compensation or public disability benefit. If the worker's compensation or public disability benefit increases, the change in the reduction amount is effective with the month of the increase. If the worker's compensation or public disability benefit decreases, the change in the reduction amount is effective with the month of the decrease, no matter when the notice of the decrease is received.