X0306 4 2017-02-15 0 0001608249 Zayo Group Holdings, Inc. ZAYO 0001502606 GTCR FUND X/A LP 300 NORTH LASALLE STREET, SUITE 5600 CHICAGO IL 60654 0 0 1 0 0001502604 GTCR FUND X/C LP 300 NORTH LASALLE STREET, SUITE 5600 CHICAGO IL 60654 0 0 1 0 0001622027 GTCR Investors (CII) LP 300 NORTH LASALLE STREET, SUITE 5600 CHICAGO IL 60654 0 0 1 0 0001622028 GTCR Partners X/A&C LP 300 NORTH LASALLE STREET, SUITE 5600 CHICAGO IL 60654 0 0 1 0 0001509286 GTCR CO-INVEST X LP 300 NORTH LASALLE STREET, SUITE 5600 CHICAGO IL 60654 0 0 1 0 0001622030 GTCR Investment X LLC 300 NORTH LASALLE STREET, SUITE 5600 CHICAGO IL 60654 0 0 1 0 Common Stock 2017-02-15 4 S 0 5000000 31.14 D 40654305 I See footnotes Consists of (i) 20,152,806 shares held of record by GTCR Fund X/A LP; (ii) 5,768,284 shares held of record by GTCR Fund X/C LP; (iii) 177,970 shares held of record by GTCR Co-Invest X LP; and (iv) 14,555,245 shares held of record by GTCR Investors (CII) LP (collectively, the "GTCR Shareholders"). GTCR Partners X/A&C LP is the general partner of each of GTCR Fund X/A LP, GTCR Fund X/C LP and GTCR Investors (CII) LP. GTCR Investment X LLC is the general partner of each of GTCR Co-Invest X LP and GTCR Partners X/A&C LP. GTCR Investment X LLC is managed by an eight-member board of managers (the "GTCR Board of Managers"). (continued) (continued from footnote 1) Each of the foregoing entities and the individual members of the GTCR Board of Managers disclaims beneficial ownership of the shares held of record by the GTCR Shareholders, except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that the reporting person is the beneficial owner of the securities for purposes of Section 16 or for any other purpose. GTCR FUND X/A LP, By: GTCR Partners X/A&C LP, its general partner, By: GTCR Investment X LLC, its general partner, By: /s/ Jeffrey S. Wright, Principal and Associate General Counsel 2017-02-17 GTCR INVESTORS (CII) LP, By: GTCR Partners X/A&C LP, its general partner, By: GTCR Investment X LLC, its general partner, By: /s/ Jeffrey S. Wright, Principal and Associate General Counsel 2017-02-17 GTCR PARTNERS X/A&C LP, By: GTCR Investment X LLC, its general partner, By: /s/ Jeffrey S. Wright, Principal and Associate General Counsel 2017-02-17 GTCR INVESTMENT X LLC, By: /s/ Jeffrey S. Wright, Principal and Associate General Counsel 2017-02-17 GTCR FUND X/C LP, By: GTCR Partners X/A&C LP, its general partner, By: GTCR Investment X LLC, its general partner, By: /s/ Jeffrey S. Wright, Principal and Associate General Counsel 2017-02-17 GTCR CO-INVEST X LP, By: GTCR Investment X LLC, its general partner, By: /s/ Jeffrey S. Wright, Principal and Associate General Counsel 2017-02-17