Section 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  membership  of  a teacher, who has not withdrawn his contributions shall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 section one hundred fifty 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 has been honorably discharged or released under honorable
  circumstances  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 who was discharged or released therefrom under honorable
  conditions,  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  was  discharged  or   released
  therefrom  under  honorable  conditions,  and  who  was a teacher in the
  public schools of this state at the time of his entrance into the  armed
  forces of the United States, provided no compensation was received under
  the provisions of section two hundred forty-two 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 pursuant to section
  forty-three of the retirement and social security law  to  transfer  his
  membership  in  the New York state teachers' retirement system, shall be
  provided  as  follows, any provisions of section two hundred forty-three
  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 section fifty-nine 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  section
  two  hundred  forty-three 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  accumulated  contributions
  immediately prior to his entry into, or during his service in the  armed
  forces  of  the  United  States  in  war after World War I, who has been
  honorably discharged or released from service, provided no  compensation
  was  received  under  the provisions of section two hundred forty-two 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
  section two hundred forty-three 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 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, 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.   has   been  honorably  discharged  or  released  under  honorable
  circumstances 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  section  forty-three  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  section  two
  hundred  forty-two  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 section two hundred forty-three 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 the education law  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 section two hundred
  forty-three 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 was discharged
  or released therefrom under honorable conditions, 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 was discharged or released therefrom under honorable
  conditions  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 section two hundred  forty-three
  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 section two hundred
  forty-three 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 was discharged
  or released therefrom under honorable conditions, 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 was discharged or released therefrom under honorable
  conditions 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.