Tier I of an employee annuity is an amount similar to the social security benefit the employee would receive based on combined railroad and social security earnings. The tier I benefit is computed as follows:

(a) A tier I PIA is computed based on combined railroad and social security earnings, as shown in §225.11 of this chapter. This PIA is adjusted for any delayed retirement credits or cost-of-living increases, as shown in subparts D and E of part 225 of this chapter, and is reduced for receipt of a pension based upon non-covered service in accordance with section 215(a)(7) of the Social Security Act. The tier I of a disability annuity may also be adjusted for other benefits based on disability, as shown in §§226.70-226.74 of this part. Except in the case of an employee who retires at age 60 with 30 years of service, if the result is not a multiple of $1, it is rounded to the next lower multiple of $1. In the case of an employee who retires with an age reduced annuity based upon 30 years of service (see §216.31 of this chapter) the tier I is not rounded until all reductions have been made.

(b) If the employee is entitled to a reduced age annuity (see §216.31 of this chapter), the rate from paragraph (a) of this section is multiplied by a fraction for each month the employee is under retirement age on the annuity beginning date. The result is subtracted from the rate in paragraph (a) of this section. At present the fraction is 5⁄9 of 1% (or 1⁄180 ). If the employee retires before age 62 with at least 30 years of service, the employee is deemed age 62 for age reduction purposes and a 20% reduction is applied. This reduction remains in effect until the first full month throughout which the employee is age 62, at which time the tier I is recomputed to reflect interim increases in the national wage levels and the age reduction factor is recomputed, if necessary, in accordance with this paragraph.

(c) The amount from paragraph (a) or (b) of this section is reduced by the amount of any monthly benefit payable to the employee under title II of the Social Security Act, including any social security benefit payable under a totalization agreement between the Social Security Administration and another country. The social security benefit used to reduce the tier I may be an age or disability benefit on the employee's own earnings record, a benefit based on the earnings record of another person, or the total of two types of benefits. The amount of the social security benefit used to reduce tier I is before any deduction for excess earnings. It is after any reduction for other benefits based on disability. The result cannot be less than zero.

(d) The tier I is subject to automatic annual increases as provided for in subpart E of part 225 of this chapter.