ADDENDUM TO
                              EMPLOYMENT AGREEMENT
                                 BY AND BETWEEN
                           THE BANK OF GREENE COUNTY,
                           GREENE COUNTY BANCORP, INC.
                                       AND
                               MICHELLE M. PLUMMER


     This Addendum (the  "Addendum") to that certain  employment  agreement (the
"Employment  Agreement") by and between The Bank of Greene  County,  a federally
chartered  stock  savings bank (the "Bank"),  with its principal  administrative
office at 302 Main Street,  Catskill, New York, Greene County Bancorp, Inc., the
holding  company of the Bank (the  "Company"),  and  Michelle  M.  Plummer  (the
"Executive") is made effective as of this 26th day of November, 2008.

     WHEREAS,  the  Executive  is  currently  employed  as  the  Executive  Vice
President,  Chief Operating  Officer and Chief Financial Officer of the Bank and
the Company; and

     WHEREAS,  the Bank,  the  Company  and the  Executive  desire to revise the
Employment Agreement to comply with the final treasury  regulations  promulgated
under Code Section 409A.

     NOW,  THEREFORE,  in consideration of the premises and the mutual covenants
and conditions  hereinafter  set forth,  the Bank, the Company and the Executive
hereby agree to the following amendments to the Employment  Agreement,  it being
understood  and agreed that except to the amendments  specifically  provided for
herein,  the remaining  terms of the Employment  Agreement  shall remain in full
force and effect:

     1. Section 3(d) of the Employment  Agreement shall be revised by adding the
following sentence to the end thereof:

"All such  reimbursements  and compensation  pursuant to this Section 3 shall be
paid  promptly  and in any event no later than March 15 of the year  immediately
following  the year in which the expense was  incurred or the  compensation  was
earned."

     2.  Section  4(a)(ii)  of the  Employment  Agreement  shall be  amended  by
revising the last paragraph thereof to read as follows:

"Upon the  occurrence of any event  described in clauses (ii) (A), (B), (C), (D)
or (E),  above,  the  Executive  shall have the right to elect to terminate  her
employment  under  this  Agreement  by  resignation  upon  sixty (60) days prior
written  notice  given  within a  reasonable  period of time not to exceed  four
calendar  months  after the  initial  event  giving rise to said right to elect.
Notwithstanding the preceding  sentence,  in the event of a continuing breach of
this Agreement by the Bank,  the  Executive,  after giving due notice within the
prescribed time frame of an initial event specified  above,  shall not waive any
of her rights  solely under this  Agreement  and this Section 4 by virtue of the
fact that the Executive has  submitted her  resignation  but has remained in the
<PAGE>


employment of the Bank and is engaged in good faith  discussions  to resolve any
occurrence of an event described in clauses (A), (B), (C), (D) and (E) above."

     3.  Section  4(b) of the  Employment  Agreement  is  revised  to change the
reference to "Executive's  termination" to "Executive's  Date of Termination" in
the  second  sentence  thereof  and to delete  the third  and  fourth  sentences
thereof.

     4. Section 4(e) is revised by adding the following to the end thereof:

"In the  event a  reduction  is  necessary,  Executive  shall  be  permitted  to
determine  the  benefits to be reduced  hereunder  to avoid an excess  parachute
payment,  provided that the exercise of such  discretion  would not be deemed to
violate Code Section 409A. If Executive's exercise of discretion would be deemed
to violate Code Section 409A,  then the  reduction  shall be made first from the
cash severance payable and then from the non-taxable medical benefits,  but only
to the extent necessary to be a Non-Triggering Amount."

     5. Section 4(g) is hereby added and shall state as follows:

     "(g) For  purposes  of this  Section 4, an "Event of  Termination"  as used
herein shall mean  "Separation from Service" as defined in Code Section 409A and
the Treasury Regulations  promulgated  thereunder,  provided,  however, that the
Bank  and the  Executive  reasonably  anticipate  that the  level  of bona  fide
services  the  Executive  would  perform  after  termination  would  permanently
decrease  to a level  that is less  than 50% of the  average  level of bona fide
services  performed  (whether as an employee or an independent  contractor) over
the immediately preceding 12-month period.

     6. The second paragraph of Section 5 shall be revised to read as follows:

     "In the event the  Executive  is unable to perform  her  duties  under this
Agreement  on a full-time  basis for a period of six (6)  consecutive  months by
reason of "Disability," the Employer may terminate this Agreement, provided that
the Employer shall continue to be obligated to pay the Executive her Base Salary
for the remaining  term of the Agreement,  or one year,  whichever is the longer
period of time, in accordance  with the regular  payroll  practices of the Bank,
and provided further that any amounts actually paid to the Executive pursuant to
any  disability  insurance or other  similar such program which the Employer has
provided or may provide on behalf of its  employees or pursuant to any workman's
or social security  disability  program shall reduce the compensation to be paid
to the Executive pursuant to this paragraph.  For these purposes,  the Executive
shall be deemed to have a  "Disability"  in any case in which it is  determined:
(i) the  Executive is unable to engage in any  substantial  gainful  activity by
reason of any medically  determinable physical or mental impairment which can be
expected to result in death, or last for a continuous period of not less than 12
months;  (ii)  by  reason  of any  medically  determinable  physical  or  mental
impairment  which can be expected to result in death,  or last for a  continuous
period  of not less  than 12  months,  and the  Executive  is  receiving  income
replacement  benefits  for a  period  of not less  than  three  months  under an
accident and health plan covering  employees of the Bank; or (iii) by the Social
Security Administration, that the Executive is totally disabled."

                                       2
<PAGE>

     7. The following paragraph shall be added to the end of Section 5 and shall
read as follows:

     "The payment of Base Salary to an Executive following  Disability or to the
legal  representative  or beneficiary of a deceased  Executive  shall be made in
accordance with the Bank's normal payroll practices."

     8. The following is added to the end of the first sentence of Section 18:

", and that such  payment  or  reimbursement  shall  occur no later than two and
one-half months after the dispute is settled in the Executive's favor."

     IN WITNESS  WHEREOF,  the Bank and the Company have caused this Addendum to
be executed on their behalf by their duly authorized officers, and Executive has
set her hand as of the date first written above.


                                        THE BANK OF GREENE COUNTY



Dated:   November 26, 2008              By: /s/ Rebecca R. Main
                                            -----------------------------------


                                        GREENE COUNTY BANCORP, INC.




Dated:   November 26, 2008              By: /s/ Donald E. Gibson
                                            -----------------------------------
                                            Donald E. Gibson

                                        EXECUTIVE




Dated:   November 26, 2008              By: /s/ Michelle M. Plummer
                                            -----------------------------------
                                            Michelle M. Plummer