X0206 3 2019-02-04 0 0001609212 AMG Pantheon Master Fund, LLC N/A 0001766775 Leaf Wilmes Kathryn C/O PANTHEON VENTURES (US) LP 600 MONTGOMERY STREET SAN FRANCISCO CA 94111 0 0 0 1 Portfolio Manager Units of beneficial ownership 0 D Kathryn Leaf Wilmes is a Managing Director of Pantheon (US) LLC, the general partner of Pantheon Ventures (US) LP, the investment adviser of the fund, and does not beneficially own any securities in the fund. /s/ Kathryn Leaf Wilmes 2019-02-05