Sec. 6.04. CALCULATION OF REGULAR DISABILITY BENEFITS. (a) Subject to Subsection (g) of this section, if a Group A member's application for a Group A disability pension has been approved by the board pursuant to Section 6.03 of this article, including any procedures adopted under that section, the Group A member may elect to receive a Group A disability pension calculated:

(1) in the same manner as the benefit under Sections 6.01(b) and (c) of this article; or

(2) under Subsection (c) of this section.

(b) An election under Subsection (a) of this section, once approved by the board, is irrevocable.

(c) Subject to Subsection (g) of this section, a Group A member who elects to have benefits determined under this subsection is entitled to a monthly disability pension calculated as follows:

(1) at a rate of three percent of base pay for each year, prorated for fractional years, of pension service, with a maximum of 32 years of pension service being credited, or 96 percent of base pay, except that if the Group A member had 34 or more years of pension service as of April 30, 1990, the member is entitled to receive the greater of a disability pension calculated under the terms of the combined pension plan in effect on that date or as calculated under this subdivision; plus

(2) one-half of the longevity pay the Group A member was receiving at the time the member left active service; plus

(3) subject to Subsection (d) of this section, 1/24th of the annualized amount of city service incentive pay the Group A member received at the time the member left active service.

(c-1) The disability pension calculated under Subsection (c) of this section may not exceed the greater of:

(1) 90 percent of the member's average base pay determined under the applicable subsection; or

(2) the vested and accrued disability pension of the member as determined on August 31, 2017.

(d) Payments of the amounts described by Subsection (c)(3) of this section are contingent on the city's continuing payment of city service incentive pay to Group A members on active service.

(e) If a Group B member's application for a Group B disability pension has been approved by the board under Section 6.03 of this article, including any procedures adopted under that section, the Group B member may elect to receive a Group B disability pension calculated in the manner described by Subsection (f) or (f-1) of this section, subject to Subsection (g) of this section.

(f) Subject to Subsections (f-1), (f-3), and (g) of this section, the disability pension of a Group B member shall be calculated as follows:

(1) for a member who began active service before March 1, 2011, the member's disability pension shall be the sum of:

(A) the member's number of years of pension service earned before September 1, 2017, prorated for fractional years, times three percent of the average computation pay determined over the 36 consecutive months of pension service in which the member received the highest computation pay; plus

(B) the number of years of pension service, including pension service credit imputed under Section 6.05(c) of this article, earned on or after September 1, 2017, prorated for fractional years, times the applicable percentage prescribed by Section 6.02(b-1) of this article of the average computation pay determined over the 60 consecutive months of pension service in which the member received the highest computation pay; or

(2) for a member who began active service on or after March 1, 2011, the member's disability pension shall be the number of years of pension service, including pension service credit imputed under Section 6.05(c) of this article, prorated for fractional years, times 2.5 percent of the average computation pay determined over the 60 consecutive months of pension service in which the member received the highest computation pay.

(f-1) Notwithstanding Subsection (f) of this section, for a Group B member who had 34 or more years of pension service as of April 30, 1990, the member is entitled to receive the greater of a disability pension calculated under the terms of Plan B in effect on April 30, 1990, or calculated under Subsection (f) of this section.

(f-2) For purposes of Subsections (f) and (f-1) of this section:

(1) any partial year of pension service for a Group B member's first 20 years of pension service is counted as a full year of pension service, if the member was considered by the member's department to have worked a normal full-time schedule at the time of the disability;

(2) if the member has less than 36 or 60 consecutive months of pension service, as applicable, the member's average computation pay will be computed based on the member's entire pension service; and

(3) days during which the member earned no pension service due to a termination of active service or otherwise must be disregarded in determining the 36 or 60 consecutive months of highest computation pay.

(f-3) The disability pension calculated under Subsection (f) or (f-1) of this section may not exceed the greater of:

(1) 90 percent of the member's average computation pay determined under the applicable subsection; or

(2) the vested and accrued disability pension of the member as determined on August 31, 2017.

(g) The disability pension calculated in accordance with this section, including both a Group A benefit described by Subsection (a) of this section and a Group B benefit described by Subsection (f) of this section, shall be reduced dollar-for-dollar by any monthly disability compensation benefit received under Section 6.05 of this article. If the monthly disability compensation benefit provided to a member under Section 6.05 of this article equals or exceeds any benefit the member is entitled to under this section or Section 6.01(b) or (c) of this article, the member may not receive the benefit under this section.