The reduction amount is not changed when a tier I benefit increases because of a recomputation or a general adjustment in annuity rates, such as a cost-of-living increase. However, the reduction amount may change for the following reasons:
Example: An employee became entitled to an annuity with a tier I component of $500 on May 1, 1991. He was also receiving a state disability benefit of $300 a month based on employment not covered under the Social Security Act. On June 1, 1991, the employee's tier I increased to $520.70. On October 1, 1991, the employee's wife becomes entitled to an annuity with a tier I benefit of $260.00. The tier I amount ($250) that would have been payable to the wife on May 1, 1991 (assuming she had been eligible for a benefit at that time) is used to determine the reduction for other disability benefits beginning October 1, 1991.
Example: The employee's tier I benefit is $500 on May 1, 1991, when the annuity is first reduced for other disability benefits. The tier I increases to $520 effective June 1, 1991. When the amount of the disability benefit changes on October 1, 1991, $500, not $520, is used as the employee tier I amount in recomputing the reduction amount.
20 C.F.R. §226.73