(i) who has completed twenty or more years of credited service; and

(ii) who has paid, before the effective date of retirement, all additional member contributions and interest (if any) required by subdivision e of this section; and

(iii) who files with the retirement system of which he or she is a member an application for service retirement setting forth at what time he or she desires to be retired; and

(iv) who shall be a participant in the twenty-year retirement program at the time so specified for his or her retirement; shall be retired pursuant to the provisions of this section affording early service retirement. 2. (i) Notwithstanding any other provision of law to the contrary, the early service retirement benefit for participants in the twenty-year retirement program who retire pursuant to paragraph one of this subdivision shall be a pension consisting of:

(A) an amount, on account of twenty years of credited service, equal to one-half of his or her final average salary; plus

(B) an amount for each additional year of credited service, or fraction thereof, beyond such twenty years of credited service equal to one-sixtieth of the final average salary for such credited service during the period from the completion of twenty years of credited service to the date of retirement.

(ii) The maximum pension computed without optional modification payable pursuant to subparagraph (i) of this paragraph shall equal that payable upon completion of thirty years of service. d. Vesting. 1. A participant in the twenty-year retirement program who:

(i) discontinues service in the uniformed force of the New York city department of correction while he or she is a New York city correction officer below the rank of captain, other than by death or retirement; and

(ii) prior to such discontinuance, completed five but less than twenty years of credited service; and

(iii) has paid, prior to such discontinuance, all additional member contributions and interest (if any) required by subdivision e of this section; and

(iv) does not withdraw in whole or in part his or her accumulated member contributions pursuant to section five hundred seventeen of this article unless such participant thereafter returns to public service and repays the amounts so withdrawn, together with interest, pursuant to such section five hundred seventeen; shall be entitled to receive a deferred vested benefit as provided in this subdivision. 2. (i) Upon such discontinuance under the conditions and in compliance with the provisions of paragraph one of this subdivision, such deferred vested benefit shall vest automatically.

(ii) Such vested benefit shall become payable on the earliest date on which such discontinued member could have retired for service if such discontinuance had not occurred. 3. Such deferred vested benefit shall be a pension consisting of an amount equal to two and one-half percent of such discontinued member's final average salary, multiplied by the number of years of credited service on the date of such discontinuance. e. Additional member contributions. 1. In addition to the member contributions required by section five hundred seventeen of this article, each participant in the twenty-year retirement program shall contribute (subject to the applicable provisions of section 13-125.1 of the administrative code) an additional percentage of his or her compensation to the retirement system of which he or she is a member in accordance with the following schedule:

(i) each such participant who became a New York city correction member below the rank of captain prior to July first, nineteen hundred eighty-eight shall contribute an additional five and eleven one-hundredths percent of his or her compensation earned from all credited service rendered on and after the starting date of the twenty-year retirement program;

(ii) each such participant who became or becomes a New York city correction member below the rank of captain for the first time on or after July first, nineteen hundred eighty-eight shall contribute an additional three and sixty-one one-hundredths percent of his or her compensation earned from all credited service earned as a correction officer below the rank of captain rendered on or after the starting date of the twenty-year retirement program. A participant in the twenty-year retirement program shall contribute additional member contributions only until he or she has twenty years of credited service. 2. Commencing with the first full payroll period after each person becomes a participant in the twenty-year retirement program, additional member contributions at the applicable rate specified in paragraph one of this subdivision shall be deducted (subject to the applicable provisions of section 13-125.1 of the administrative code) from the compensation of such participant on each and every payroll of such participant for each and every payroll period. 3. (i) Subject to the provisions of subparagraph (ii) of this paragraph, where any additional member contributions required by paragraph one of this subdivision are not paid by deductions from a participant's compensation pursuant to paragraph two of this subdivision:

(A) that participant shall be charged with a contribution deficiency consisting of such unpaid amounts, together with interest thereon at the rate of five percent per annum, compounded annually; and

(B) such interest on each amount of undeducted contributions shall accrue from the end of the payroll period for which such amount would have been deducted from compensation if he or she had been a participant at the beginning of that payroll period, until such amount is paid to the retirement system.

(ii) Except as provided in subparagraph (iii) of this paragraph, no interest shall be due on any such unpaid additional contributions which are not attributable to the period prior to the first full payroll period referred to in paragraph two of this subdivision.

(iii) Should any person who, pursuant to paragraph eight of this subdivision, has withdrawn any additional member contributions (and any interest paid thereon) again become a participant in the twenty-year retirement program pursuant to paragraph six of subdivision b of this section, an appropriate amount shall be included in such participant's contribution deficiency (including interest thereon as calculated pursuant to subparagraph (i) of this paragraph) as if such additional contributions had never been made. 4. The head of a retirement system which includes participants in the twenty-year retirement program in its membership may, consistent with the provisions of this subdivision, promulgate regulations for the payment of such additional member contributions, and any interest thereon, by such participants (including the deduction of such contributions, and any interest thereon, from the participants' compensation). 5. Where a contribution deficiency chargeable to a participant pursuant to paragraph three of this subdivision has not been paid in full before the effective date of retirement, that participant shall not be eligible to retire pursuant to subdivision c of this section. 6. Where a contribution deficiency chargeable to a participant pursuant to paragraph three of this subdivision has not been paid in full before the date of discontinuance of service, that participant shall not be entitled to a deferred vested benefit pursuant to subdivision d of this section. 7. Where a participant has not paid in full any contribution deficiency chargeable to him or her pursuant to paragraph three of this subdivision, and a benefit, other than a refund of member contributions pursuant to section five hundred seventeen of this article or a refund of additional member contributions pursuant to paragraph eight of this subdivision, becomes payable under this article to the participant or to his or her designated beneficiary or estate, the actuarial equivalent of any such unpaid amount shall be deducted from the benefit otherwise payable. 8. (i) Such additional member contributions (and any interest thereon) shall be paid into the contingent reserve fund of the retirement system of which the participant is a member and shall not for any purpose be deemed to be member contributions or accumulated contributions of a member under section five hundred seventeen of this article or otherwise while he or she is a participant in the twenty-year retirement program or otherwise, except that, a surplus of such additional member contributions that are paid into the retirement system's contingent reserve fund may be used for the sole purpose of offsetting a deficit of basic member contributions.

(ii) (A) Except as otherwise provided in subparagraph (iii) of this paragraph, should a participant in the twenty-year retirement program who has rendered less than fifteen years of credited service cease to hold the position of New York city correction officer below the rank of captain for any reason whatsoever, his or her accumulated additional member contributions made pursuant to this subdivision (together with any interest thereon paid to the retirement system) may be withdrawn by him or her pursuant to procedures promulgated in regulations of the board of trustees of the retirement system, together with interest thereon at the rate of five percent per annum, compounded annually.

(B) Upon the death of a participant in the twenty-year retirement program on or after the effective date of this clause, there shall be paid to such person as he or she has nominated or shall nominate to receive his or her accumulated member contributions by written designation duly executed and filed with the retirement system during the lifetime of such participant, or, to his or her estate if no such person is nominated, his or her accumulated additional member contributions made pursuant to this subdivision (including any interest thereon paid to the retirement system), together with interest thereon at the rate of five percent per annum, compounded annually.

(iii) (A) Notwithstanding any other provisions of law to the contrary, any person who has been promoted directly from the position of New York city correction officer below the rank of captain to the position of New York city correction officer of the rank of captain or above, and who is otherwise eligible to elect to become a participant in the twenty-year retirement program for captains and above pursuant to paragraph one or two of subdivision b of section five hundred four-b of this article, and who withdraws any portion of his or her accumulated additional member contributions pursuant to subparagraph (ii) of this paragraph on or after the starting date of the twenty-year retirement program for captains and above shall not be eligible to elect to become a participant in the twenty-year retirement program for captains and above pursuant to paragraph one or two of subdivision b of such section five hundred four-b.

(B) Notwithstanding any other provision of law to the contrary, any person who is promoted directly from the position of New York city correction officer below the rank of captain to the position of New York city correction officer of the rank of captain or above and who, upon such promotion, becomes a participant in the twenty-year retirement program for captains and above pursuant to paragraph four of subdivision b of section five hundred four-b of this article, shall not be permitted to withdraw any portion of his or her accumulated additional member contributions pursuant to the provisions of subparagraph (ii) of this paragraph at any time while he or she is a participant in the twenty-year retirement program for captains and above.

(C) Notwithstanding any other provision of law to the contrary, any former participant in the twenty-year retirement program who becomes a participant in the twenty-year retirement program for captains and above pursuant to any provision of subdivision b of section five hundred four-b of this article, and who has additional member contributions on deposit in the contingent reserve fund of the retirement system at the time he or she becomes a participant in the twenty-year retirement program for captains and above, shall not be permitted to withdraw any portion of such accumulated additional member contributions pursuant to the provisions of subparagraph (ii) of this paragraph at any time while he or she is a participant in the twenty-year retirement program for captains and above.

(iv) Except as provided in subparagraph (ii) of this paragraph, no member while he or she is a participant or otherwise, shall have a right to withdraw such additional member contributions or any interest thereon from the retirement system. 9. No member of a public retirement system shall be permitted to borrow any portion of the additional member contributions (including any interest paid thereon by the participant) which are subject to this subdivision. f. The escalation of benefits provisions of section five hundred ten of this article shall not apply to any benefits received pursuant to the provisions of this section. g. Except as provided in item (B) of subparagraph (i) of paragraph two of subdivision c of this section, the provisions of subdivision d of section five hundred of this article shall apply to participants under this section. h. In the event that the provisions of this section should result in any increase in the contribution rate of the city of New York, that increase shall not apply to any calculation or certification for the purposes of subdivision c of section five hundred of this article.