§ 503. Membership of system. 1. The membership of the retirement system shall consist of the following:

a. All teachers who were teachers on or before the first day of August, nineteen hundred twenty-one, who shall file with the retirement board applications for membership, except those specifically excluded under subdivision four of this section.

b. All teachers who were not teachers on or before the first day of August, nineteen hundred twenty-one, except those specifically excluded under subdivision four of this section.

2. The retirement board may, in its discretion, deny the right to become members to any class of teachers whose compensation is only partly paid by the employer or who are serving on a temporary or any other than a per annum basis, and it may also, in its discretion, make optional with members in any such class their individual entrance into membership.

3. The membership of any person in the retirement system shall cease when seven years have elapsed since the member has performed service as a teacher which was credited with the system except as provided in section five hundred twelve-a of this article, or upon the withdrawal by a contributor of his accumulated contributions as provided in this article, or upon retirement on a pension, or at death, except that the membership of a teacher, who has not withdrawn his contributions shall not be cancelled if he (a) has not had sufficient service to be eligible for disability retirement, and proves to the satisfaction of the retirement board that absence from service was caused by personal illness constituting disability or (b) is eligible to receive a retirement allowance from the system for other than disability.

4. Teachers who are members or who become members of a local district pension system maintained under the laws of the state from appropriations or contributions made wholly or partly by an employer shall be excluded from membership in this retirement system.

5. A retired teacher receiving a retirement allowance for other than disability may return to active public service. Any such retired teacher returning to active service shall immediately notify the retirement board of his intention. Except as otherwise provided in sections two hundred eleven and two hundred twelve of the retirement and social security law and § 150 of the civil service law, his retirement allowance shall be suspended during the time he is in active service. If such teacher has not elected an optional benefit, the payments of his annuity so suspended shall be held in the annuity reserve fund at regular interest, and upon the resumption of his retirement allowance after again leaving the active service such accumulated amounts shall be applied to increase the annuity otherwise payable to him or in the event of his death while in active service such accumulated amounts shall be paid to his estate or to such person as last designated as the beneficiary of his accumulated contributions. If such teacher has elected an optional benefit and dies while in active service, the optional benefit in respect of his annuity shall be payable as if no annuity payments had been suspended, but the optional benefit in respect of his pension shall not be payable in excess of the proportion that the cost of such optional pension, when measured by the difference between his pension without optional modification and the optional pension, is currently covered by the amount of the annuity payments suspended while he is in active service, which difference shall be paid during the period of his active service from the annuity reserve fund to the fund from which his pension was payable. If, however, such full cost of the optional pension is greater than the suspended annuity payments, the teacher may elect upon returning to active service to pay the amount of such difference directly to the retirement system to be credited to the fund from which his pension was payable, and subject to such payments monthly in advance, or at such other intervals as may be agreed upon with the retirement board, the optional benefit in respect of the pension shall be payable in the event the teacher dies while in active service, as if no pension payments had been suspended. If the suspended annuity payments are greater than such full cost of the optional pension, the amount of such difference shall be held at regular interest in the annuity reserve fund, and upon the resumption of his retirement allowance after again leaving active service such accumulated amounts shall be applied to increase the annuity otherwise payable to him, or in the event of his death while in active service such accumulated amounts shall be paid to his estate or to the beneficiary nominated under the option.

6. Credit for service in war after world war I, which shall mean military service during the period commencing the first day of July, nineteen hundred forty, and terminating the thirtieth day of June, nineteen hundred forty-seven, or during the period commencing the twenty-seventh day of June, nineteen hundred fifty, and terminating the thirty-first day of January, nineteen hundred fifty-five, or during both such periods, as a member of the armed forces of the United States, of any person who (i) has been honorably discharged or released under honorable circumstances from such service, or (ii) has a qualifying condition, as defined in section one of the veterans' services law, and has received a discharge other than bad conduct or dishonorable from such service, or (iii) is a discharged LGBT veteran, as defined in section one of the veterans' services law, and has received a discharge other than bad conduct or dishonorable from such service, or service by one who was employed by the War Shipping Administration or Office of Defense Transportation or their agents as a merchant seaman documented by the United States Coast Guard or Department of Commerce, or as a civil servant employed by the United States Army Transport Service (later redesignated as the United States Army Transportation Corps, Water Division) or the Naval Transportation Service; and who served satisfactorily as a crew member during the period of armed conflict, December seventh, nineteen hundred forty-one, to August fifteenth, nineteen hundred forty-five, aboard merchant vessels in oceangoing, i.e., foreign, intercoastal, or coastwise service as such terms are defined under federal law (46 USCA 10301 & 10501) and further to include "near foreign" voyages between the United States and Canada, Mexico, or the West Indies via ocean routes, or public vessels in oceangoing service or foreign waters and who has received a Certificate of Release or Discharge from Active Duty and a discharge certificate, or an Honorable Service Certificate/Report of Casualty, from the Department of Defense or who served as a United States civilian employed by the American Field Service and served overseas under United States Armies and United States Army Groups in world war II during the period of armed conflict, December seventh, nineteen hundred forty-one through May eighth, nineteen hundred forty-five, and (iv) who was discharged or released therefrom under honorable conditions, or (v) has a qualifying condition, as defined in section one of the veterans' services law, and has received a discharge other than bad conduct or dishonorable from such service, or (vi) is a discharged LGBT veteran, as defined in section one of the veterans' services law, and has received a discharge other than bad conduct or dishonorable from such service, or who served as a United States civilian Flight Crew and Aviation Ground Support Employee of Pan American World Airways or one of its subsidiaries or its affiliates and served overseas as a result of Pan American's contract with Air Transport Command or Naval Air Transport Service during the period of armed conflict, December fourteenth, nineteen hundred forty-one through August fourteenth, nineteen hundred forty-five, and who (vii) was discharged or released therefrom under honorable conditions, or (viii) has a qualifying condition, as defined in section one of the veterans' services law, and has received a discharge other than bad conduct or dishonorable from such service, or (ix) is a discharged LGBT veteran, as defined in section one of the veterans' services law, and has received a discharge other than bad conduct or dishonorable from such service, and who was a teacher in the public schools of this state at the time of his or her entrance into the armed forces of the United States, provided no compensation was received under the provisions of § 242 of the military law, and who returned to public school teaching following discharge or completion of advanced education provided under servicemen's readjustment act of nineteen hundred forty-four, or who following such discharge or release entered into a service which would qualify him or her pursuant to § 43 of the retirement and social security law to transfer his or her membership in the New York state teachers' retirement system, shall be provided as follows, any provisions of § 243 of the military law to the contrary notwithstanding.

(a) Service in war after world war I as defined in this subdivision shall be deemed to be service for all purposes of the retirement fund, provided claim for such service shall be filed by the member with the retirement board within two years following his return to active teaching service or the entry of the member into a service which would qualify him pursuant to § 59 of the civil service law to transfer his membership to the New York city employees' retirement system or to the New York state employees' retirement system or the fifteenth day of April, nineteen hundred sixty-seven, whichever is later.

(b) For the purposes of computing final average salary, compensation during any period of service in war after world war I shall be deemed to have been at the member's rate of compensation in effect immediately prior to such period, or based on additional increments due him if he had continued teaching.

(c) Contributions paid by any member under the provisions of § 243 of the military law shall be refunded directly to the member and the corresponding contribution paid by the district shall also be returned directly to the district.

(d) On the retirement of a member with credit for service in war after world war I as defined in this subdivision, there shall be transferred from the pension accumulation fund to the annuity reserve fund a sum equivalent to the contributions the member would have made to the annuity savings fund had he contributed during his period of service in war after world war I at the rate in effect immediately prior to such period, or on additional increments due him if he had continued teaching, with interest to the date of retirement, which amounts shall be used to provide an annuity for him.

(e) In addition to the contributions required of employers to the retirement system as otherwise provided, there shall be paid an additional contribution to the pension accumulation fund to cover the cost of the additional benefits covered by this subdivision. The additional contributions shall be collected by increasing the regular contributions of the employers in the same proportion as the liabilities of the pension accumulation fund are increased by the adoption of this subdivision.

7. A teacher, who was a member of the New York state teachers retirement system but who withdrew his or her accumulated contributions immediately prior to his or her entry into, or during his or her service in the armed forces of the United States in war after World War I, who (i) has been honorably discharged or released from service, or (ii) has a qualifying condition, as defined in section one of the veterans' services law, and has received a discharge other than bad conduct or dishonorable from such service, or (iii) is a discharged LGBT veteran, as defined in section one of the veterans' services law, and has received a discharge other than bad conduct or dishonorable from such service, provided no compensation was received under the provisions of § 242 of the military law, and who returned to public school teaching in the state of New York following such discharge or release, or following completion of advanced education provided under servicemen's readjustment act of nineteen hundred forty-four, any provisions of § 243 of the military law to the contrary notwithstanding, will be entitled to credit for service in war after World War I, cost free, provided, however, that such credit will not be allowed until he or she claims and pays for all prior teaching service credited to him or her at the time of his or her termination of membership in the New York state teachers retirement system, and provided further that claim for such service in war after World War I shall be filed by the member with the retirement board before the first day of July, nineteen hundred sixty-eight.

8. A teacher who had been granted credit for service in war after world war I as provided in this section and whose membership in the New York state teachers retirement system subsequently ceased by reason of withdrawal of his accumulated contributions will, upon rejoining the New York state teachers retirement system, be entitled to the same credit for service in war after world war I, cost free, that he was credited with upon termination of his membership in the New York state teachers retirement system, provided, however, that such credit will not be allowed until he claims and pays for all prior teaching service credited to him at the time of his termination of membership in the New York state teachers retirement system.

9. Credit for emergency service on or after October first, nineteen hundred sixty-one, shall mean active duty (other than for training) in the armed forces of the United States as defined in title ten of the United States code on or after October first, nineteen hundred sixty-one and terminating on June thirtieth, nineteen hundred sixty-three or on the date that no reserve component unit originally ordered into the active service of the United States from the state on or after October first, nineteen hundred sixty-one remains on such active service, whichever sooner occurs, of any person who:

a. was a teacher in the public schools of this state at the time of his entrance into such armed forces,

b. was a member of the New York state teachers' retirement system and an employee of the state or of an employer at the time he entered such armed forces,

c. (i) has been honorably discharged or released under honorable circumstances from such service, or (ii) has a qualifying condition, as defined in section one of the veterans' services law, and has received a discharge other than bad conduct or dishonorable from such service, or (iii) is a discharged LGBT veteran, as defined in section one of the veterans' services law, and has received a discharge other than bad conduct or dishonorable from such service, and

d. returned to public school teaching within one year following discharge or release, or completion of advanced education provided by the United States for education of Korean conflict veterans, or who following such discharge or release entered into a service which would qualify him, pursuant to § 43 of the retirement and social security law, to transfer his membership in the New York state teachers retirement system. Such service shall not include any periods during which compensation was received by the member for accrued vacation and overtime credit or under the provisions of § 242 of the military law or section six of chapter six hundred eight of the laws of nineteen hundred fifty-two.

Emergency service on or after October first, nineteen hundred sixty-one, shall for the purposes of this article be deemed credit for service in war after world war I.

10. Credit for certain World War II service. a. In addition to credit for military service pursuant to § 243 of the military law and subdivisions six through nine of this section, a member employed as a full-time teacher by an employer as defined in subdivision three of section five hundred one of this article and who joined the retirement system prior to July first, nineteen hundred seventy-three, may obtain credit for military service not in excess of three years and not otherwise creditable under § 243 of the military law and subdivisions six through nine of this section, rendered on active duty in the armed forces of the United States during the period commencing July first, nineteen hundred forty, and terminating December thirty-first, nineteen hundred forty-six, or on service by one who was employed by the War Shipping Administration or Office of Defense Transportation or their agents as a merchant seaman documented by the United States Coast Guard or Department of Commerce, or as a civil servant employed by the United States Army Transport Service (later redesignated as the United States Army Transportation Corps, Water Division) or the Naval Transportation Service; and who served satisfactorily as a crew member during the period of armed conflict, December seventh, nineteen hundred forty-one, to August fifteenth, nineteen hundred forty-five, aboard merchant vessels in oceangoing, i.e., foreign, intercoastal, or coastwise service as such terms are defined under federal law (46 USCA 10301 & 10501) and further to include "near foreign" voyages between the United States and Canada, Mexico, or the West Indies via ocean routes, or public vessels in oceangoing service or foreign waters and who has received a Certificate of Release or Discharge from Active Duty and a discharge certificate, or an Honorable Service Certificate/Report of Casualty, from the Department of Defense or on service by one who served as a United States civilian employed by the American Field Service and served overseas under United States Armies and United States Army Groups in world war II during the period of armed conflict, December seventh, nineteen hundred forty-one through May eighth, nineteen hundred forty-five, and who (i) was discharged or released therefrom under honorable conditions, or (ii) has a qualifying condition, as defined in section one of the veterans' services law, and has received a discharge other than bad conduct or dishonorable from such service, or (iii) is a discharged LGBT veteran, as defined in section one of the veterans' services law, and has received a discharge other than bad conduct or dishonorable from such service, or on service by one who served as a United States civilian Flight Crew and Aviation Ground Support Employee of Pan American World Airways or one of its subsidiaries or its affiliates and served overseas as a result of Pan American's contract with Air Transport Command or Naval Air Transport Service during the period of armed conflict, December fourteenth, nineteen hundred forty-one through August fourteenth, nineteen hundred forty-five, and who (iv) was discharged or released therefrom under honorable conditions, or (v) has a qualifying condition, as defined in section one of the veterans' services law, and has received a discharge other than bad conduct or dishonorable from such service, or (vi) is a discharged LGBT veteran, as defined in section one of the veterans' services law, and has received a discharge other than bad conduct or dishonorable from such service, by a person who was a resident of New York state at the time of entry into such service and at the time of being discharged therefrom under honorable circumstances, and who makes the payments required in accordance with the provisions of this subdivision.

However, no military service shall be creditable under this subdivision in the case of a member who is receiving a military pension (other than for disability) for military service in the armed forces of the United States.

b. To obtain such credit a member shall: (1) deposit in the annuity savings fund a sum equal to the product of his required contribution rate at time of entry into full-time New York state teaching service, his annual full-time rate of compensation at that time, and the period of military service being claimed, with regular interest, and (2) deposit in the pension accumulation fund a sum equal to the product of the employer's contribution rate exclusive of the rate for supplemental pensions at the time of the member's entry into such teaching service, his annual full-time rate of compensation at that time, and the period of military service being claimed, with regular interest. Such deposit must be made on or before October fourteenth, nineteen hundred seventy-seven, provided, however, such member may elect to deposit such amount over a period of time no greater than the period for which credit is being claimed, in which case such payments must commence no later than October fourteenth, nineteen hundred seventy-seven. If the full amount of such payments is not paid to the retirement system at the time of retirement, the amount of service credited shall be proportional to the total amount of the payments made.

c. The credit for military service hereunder shall not be used to increase a service retirement benefit if, at the time of retirement, such member (1) is retiring from service with less than ten years of full-time service credit or (2) is retiring with less than three years of member service rendered subsequent to the date that he last became a member of this system. Upon retirement, as specified in (1) or (2), there shall be refunded to such member the amount of such deposit plus accrued interest exclusive of the amount deposited to the pension accumulation fund attributable to death and disability benefits.

d. (1) In the case of members who have transferred into this system from another public retirement system within the state of New York, their rate of contribution shall be computed as though they had been a member of this system from the date of membership in the retirement system from which they transferred.

(2) Any other provision of law to the contrary notwithstanding, the rate of contribution to be used in calculating contributions to the annuity savings fund pursuant to this subdivision shall be at the rate of four per centum of earnable compensation for members whose date of membership is on or before June thirtieth, nineteen hundred forty-eight and at the rate of five per centum of earnable compensation for members whose date of membership is on or after July first, nineteen hundred forty-eight.

e. In no event shall credit be granted pursuant to this subdivision if credit is granted for the same period of time pursuant to other provisions of law.

f. No application for credit pursuant to the provisions of this subdivision shall be honored if made on or after April fifteenth, nineteen hundred seventy-seven.

10-a. Credit for certain World War II service. a. In addition to credit for military service pursuant to § 243 of the military law and subdivisions six through nine of this section, a member who joined the retirement system prior to July first, nineteen hundred seventy-three, and who was not eligible for credit for military service under subdivision ten of this section as a result of being on a leave of absence without pay between July twentieth, nineteen hundred seventy-six and October fifteenth, nineteen hundred seventy-seven or on leave of absence with less than full pay between July twentieth, nineteen hundred seventy-six and October fifteenth, nineteen hundred seventy-seven, may obtain credit for military service not in excess of three years and not otherwise creditable under § 243 of the military law and subdivisions six through nine of this section, rendered on active duty in the armed forces of the United States during the period commencing July first, nineteen hundred forty, and terminating December thirty-first, nineteen hundred forty-six, or on service by one who was employed by the War Shipping Administration or Office of Defense Transportation or their agents as a merchant seaman documented by the United States Coast Guard or Department of Commerce, or as a civil servant employed by the United States Army Transport Service (later redesignated as the United States Army Transportation Corps, Water Division) or the Naval Transportation Service; and who served satisfactorily as a crew member during the period of armed conflict, December seventh, nineteen hundred forty-one, to August fifteenth, nineteen hundred forty-five, aboard merchant vessels in oceangoing, i.e., foreign, intercoastal, or coastwise service as such terms are defined under federal law (46 USCA 10301 & 10501) and further to include "near foreign" voyages between the United States and Canada, Mexico, or the West Indies via ocean routes, or public vessels in oceangoing service or foreign waters and who has received a Certificate of Release or Discharge from Active Duty and a discharge certificate, or an Honorable Service Certificate/Report of Casualty, from the Department of Defense, or on service by one who served as a United States civilian employed by the American Field Service and served overseas under United States Armies and United States Army Groups in world war II during the period of armed conflict, December seventh, nineteen hundred forty-one through May eighth, nineteen hundred forty-five, and who (i) was discharged or released therefrom under honorable conditions, or (ii) has a qualifying condition, as defined in section one of the veterans' services law, and has received a discharge other than bad conduct or dishonorable from such service, or (iii) is a discharged LGBT veteran, as defined in section one of the veterans' services law, and has received a discharge other than bad conduct or dishonorable from such service, or on service by one who served as a United States civilian Flight Crew and Aviation Ground Support Employee of Pan American World Airways or one of its subsidiaries or its affiliates and served overseas as a result of Pan American's contract with Air Transport Command or Naval Air Transport Service during the period of armed conflict, December fourteenth, nineteen hundred forty-one through August fourteenth, nineteen hundred forty-five, and who (iv) was discharged or released therefrom under honorable conditions, or (v) has a qualifying condition, as defined in section one of the veterans' services law, and has received a discharge other than bad conduct or dishonorable from such service, or (vi) is a discharged LGBT veteran, as defined in section one of the veterans' services law, and has received a discharge other than bad conduct or dishonorable from such service, by a person who was a resident of New York state at the time of entry into such service and at the time of being discharged therefrom under honorable circumstances, and who makes the payments required in accordance with the provisions of this subdivision.

However, no military service shall be creditable under this subdivision in the case of a member who is receiving a military pension (other than for disability) for military service in the armed forces of the United States.

b. To obtain such credit a member shall: (1) deposit in the annuity savings fund a sum equal to the product of his required contribution rate at time of entry into full-time New York state teaching service, his annual full-time rate of compensation at that time, and the period of military service being claimed, with regular interest, and (2) deposit in the pension accumulation fund a sum equal to the product of the employer's contribution rate exclusive of the rate for supplemental pensions at the time of the member's entry into such teaching service, his annual full-time rate of compensation at that time, and the period of military service being claimed, with regular interest. Such deposit must be made on or before October fourteenth, nineteen hundred eighty, provided, however, such member may elect to deposit such amount over a period of time no greater than the period for which credit is being claimed, in which case such payments must commence no later than October fourteenth, nineteen hundred eighty. If the full amount of such payments is not paid to the retirement system at the time of retirement, the amount of service credited shall be proportional to the total amount of the payments made.

c. The credit for military service hereunder shall not be used to increase a service retirement benefit if, at the time of retirement, such member (1) is retiring from service with less than ten years of full-time service credit or (2) is retiring with less than three years of member service rendered subsequent to the date that he last became a member of this system. Upon retirement, as specified in (1) or (2), there shall be refunded to such member the amount of such deposit plus accrued interest exclusive of the amount deposited to the pension accumulation fund attributable to death and disability benefits.

d. (1) In the case of members who have transferred into this system from another public retirement system within the state of New York, their rate of contribution shall be computed as though they had been a member of this system from the date of membership in the retirement system from which they transferred.

(2) Any other provision of law to the contrary notwithstanding, the rate of contribution to be used in calculating contributions to the annuity savings fund pursuant to this subdivision shall be at the rate of four per centum of earnable compensation for members whose date of membership is on or before June thirtieth, nineteen hundred forty-eight and at the rate of five per centum of earnable compensation for members whose date of membership is on or after July first, nineteen hundred forty-eight.

e. In no event shall credit be granted pursuant to this subdivision if credit is granted for the same period of time pursuant to other provisions of law.

f. No application for credit pursuant to the provisions of this subdivision shall be honored if made on or after October fifteenth, nineteen hundred eighty.

11. a. If a retired member, receiving a retirement allowance for other than disability, returns to active public service, except as otherwise provided in sections two hundred eleven or two hyndred twelve of the retirement and social security law, and is eligible for membership in the retirement system, he thereupon shall become a member and his retirement allowance shall be suspended in the same manner as provided in subdivision five of section five hundred three of this article. In such event, he shall contribute to the retirement system as if he were a new member. Upon his subsequent retirement after at least two years of service he shall:

1. Be credited with all member service earned by him since he last became a member of the retirement system, and

2. Receive a retirement allowance which shall consist of:

(a) An annuity as provided in subdivision five of section five hundred three of this article plus an annuity which is the actuarial equivalent of any contributions made by him since he last became a member, and

(b) The pension which he was receiving immediately prior to his last restoration to membership as provided in subdivision five of section five hundred three of this article, plus a pension based upon the member service credit earned by him since he last became a member. Such latter pension shall be computed as if he were a new member when he rejoined the system pursuant to the provisions of this subdivision.

b. Where such member shall have earned at least five years of member service credit after restoration to active service, the total service credit to which he was entitled at the time of his earlier retirement may, at his option, again be credited to him and upon his subsequent retirement he shall be credited in addition for purposes of computation of the pension portion of the retirement allowance with all member service earned by him subsequent to his last restoration to membership. Such total service credit to which he was entitled at the time of his earlier retirement shall be so credited only in the event that such member returns to the retirement system with regular interest the actuarial equivalent of the amount of the pension he received, or in the event that such amount is not so repaid the actuarial equivalent thereof shall be deducted from his subsequent retirement allowance.

c. Notwithstanding the foregoing provisions of this subdivision, a retired member who is receiving a retirement allowance for other than physical disability, and who returns to active public service, may elect not to be restored to membership in the retirement system until he has rendered one year of service following his return to public service. In such event his retirement allowance shall be suspended during such year of service in the same manner as provided in subdivision five of section five hundred three of this article. Upon restoration to membership following completion of such year of service, his service in such year shall be deemed to be service while a member for purposes of subdivision b of section five hundred twelve of this article. He may purchase member service credit for such year, which shall be deemed earned member service credit.

d. Notwithstanding any other provision of this article, a retired member who rejoins the system under the provisions of paragraphs a or c of this subdivision shall only be entitled to a death benefit according to the provisions of paragraph two of subdivision b of section five hundred twelve of this article and of no other subdivision thereof and for the purposes of said paragraph two of subdivision b of section five hundred twelve the credited service as a teacher shall be service as a teacher credited since last joining the system.