Amendment to the Retirement Plan

Eligibility. The single lump-sum payment option described in subsection (c) below, as well as the immediate annuity option described in subsection (d) below, shall be available only to any Eligible Window Participant who makes a timely election during the Lump-Sum Window Period. The lump-sum payment described in subsection (c) or immediate annuity described in subsection (d) shall be calculated as of the Window Benefit Commencement Date, subject to the limitation described in subsection (g) below.

Notice and Election Period. A formal notice describing the Lump-Sum Window and all related election rights shall be distributed to Eligible Window Participants during August 2017, as determined by the Committee.

Lump-Sum Amount Option. An Eligible Window Participant may elect to receive a lump-sum payment of his entire accrued benefit under the Plan, determined as of the Window Benefit Commencement Date. In the event that a Participant receives such a lump-sum payment and is subsequently reemployed as an Eligible Employee, the Participant will have his Vesting Service and Credited Service restored but any benefit payable as of his subsequent termination of employment with the Sponsor and all Affiliates will, consistent with the terms of Plan section 5.5, be reduced by the Actuarial Equivalent value of the Lump-Sum Window benefit that was previously paid.

Immediate Annuity Option. An Eligible Window Participant who has not reached his Vested Retirement Date or Early Retirement Date (as applicable) as of the Window Benefit Commencement Date, and, therefore, is not otherwise eligible under Article 4 to commence receiving benefits in the form of an immediate annuity, nevertheless may, in lieu of the lump-sum distribution option described in subsection (c) above, elect to commence receiving his benefit as of the Window Benefit Commencement Date in the form of an immediately payable annuity which provides payments under a Life Only Option as described in Plan section 4.9(c)(1) if the Eligible Window Participant is not married or as, a Joint and 50 Percent Contingent Benefit Option as described in Plan section 4.9(c)(3), or a Qualified Optional Survivor Annuity Option (Joint and 75 percent contingent benefit option) as described in Plan section 4.9(c)(7) if the Eligible Window Participant is married. Such immediately payable annuity shall be adjusted for time and form of payment as contemplated by Articles 4 and 5 of the Plan, respectively.

Death after Election and Prior to Benefit Commencement. Notwithstanding anything to the contrary in this Article 4, in the case of an Eligible Window Participant who makes and files with the Committee representative a written election under subsection (b) above, on or before the Offer Closing Date, but who subsequently dies prior to receiving or commencing to receive distributions under this Plan section 4.18, such election shall be given full effect, in a manner determined by the Committee. In the case of an election by such a deceased Eligible Window Participant to receive a lump-sum distribution, such lump-sum payment shall be made to the Surviving Spouse if the deceased Eligible Window Participant was married, or to the Participant’s estate if the Eligible Window Participant was not married, at the time of death. The provisions of this subsection (e) shall apply only for purposes of distributions payable under this Plan section 4.18, and not for any other purpose under the Plan.

Actuarial Factors Used to Calculate Lump-Sum Payments. The “applicable interest rate” and “applicable mortality table” shall have the meaning provided to such terms as described in Plan section 2.1(a), defining “Actuarial Equivalent,” for the calculation of lump-sum distributions under the Lump-Sum Window.

Lump-Sum Window Offer Contingent on Aggregate Lump-Sum Payments not Exceeding $5,665,000. The lump-sum offer reflected in this Plan section 4.18 is conditioned on the Sponsor’s determination that any lump-sum benefit paid pursuant to this Lump-Sum Window offer will not result in the payment of lump-sum exceeding $5,665,000 in the aggregate. If lump-sum payments payable pursuant to this Lump-Sum Window would exceed $5,665,000, the Sponsor will pay lump-sum payments to each electing Eligible Window Participant who made a timely election during the Lump-Sum Window Period starting with the smallest lump sum payment first and proceeding to pay lump sum payments of a successively increasing dollar amount until the aggregate lump sum benefits paid pursuant to this Lump-Sum Window do not exceed $5,665,000. And the payment of any lump-sum benefit that would result in this Lump-Sum Window offer paying lump sum distributions in excess of $5,665,000 in the aggregate will be null and void, and the election by one or more such Participants to receive a lump-sum distribution will not be given effect. The administration of this limitation on the aggregate lump-sum payments that may be paid pursuant to this Lump-Sum Window will be administered on a uniform and nondiscriminatory basis to all similarly situated persons.

Definitions. For purposes of this Plan section 4.18, the following definitions will apply:

“Eligible Window Participant” means a Participant who (i) terminated employment from the Sponsor and all Affiliates prior to January 1, 2017, (ii) has not subsequently been rehired by the Sponsor or an Affiliate on or prior to the Window Benefit Commencement Date, (iii) has a vested accrued benefit in the Plan the Actuarial Equivalent of which as of the Window Benefit Commencement Date is not more than $40,000 (exclusive of any interest such Participant has in an annuity contract covering accrued benefits earned under the Cullen/Frost Superseded Plan and as further described in Appendix A), (iv)

“Lump-Sum Window” means the opportunity described in this Plan section 4.18 for any Eligible Window Participant to make a timely election for the single lump-sum payment option described in subsection (c) above, or the immediate annuity option described in subsection (d) above, during the Lump-Sum Window Period.

“Lump-Sum Window Period” means the period beginning after the formal notice referenced in subsection (b) above has been provided, and ending on the Offer Closing Date.

“Offer Closing Date” means the latest permissible date on which an eligible Participant may elect to receive a lump-sum distribution or other payment under the provisions of this Plan section 4.18. Such date shall be on or around September 29, 2017, as determined by the Committee; provided, however, that the Committee may choose to permit minor extensions beyond such Offer Closing Date (e.g., to allow Participants to complete small errors or omissions in paperwork, or to allow for unexpected delays in the Lump-Sum Window election package delivery process); and further provided, however, that any such extensions shall be applied on a uniform and nondiscriminatory basis to all similarly situated persons.

“Window Benefit Commencement Date” means November 1, 2017.

Except as amended above, the Plan as in effect prior to this amendment shall continue unchanged.