  We present the results of a search for ammonia maser emission in 119 Galactic
high-mass star-forming regions (HMSFRs) known to host 22 GHz H$_2$O maser
emission. Our survey has led to the discovery of non-metastable NH$_3$
inversion line masers toward 14 of these sources. This doubles the number of
known non-metastable ammonia masers in our Galaxy, including nine new very high
excitation ($J,K$)~=~(9,6) maser sources. These maser lines, including NH$_3$
(5,4), (6,4), (6,5), (7,6), (8,6), (9,6), (9,8), (10,8), and (11,9), arise from
energy levels of 342 K, 513 K, 465 K, 606 K, 834 K, 1090 K, 942 K, 1226 K, and
1449 K above the ground state. Additionally, we tentatively report a new
metastable NH$_3$ (3,3) maser in G048.49 and an NH$_3$ (7,7) maser in G029.95.
Our observations reveal that all of the newly detected NH$_3$ maser lines
exhibit either blueshifted or redshifted velocities with respect to the source
systemic velocities. Among the non-metastable ammonia maser lines, larger
velocity distributions, offset from the source systemic velocities, are found
in the ortho-NH$_3$ ($K=3n$) than in the para-NH$_3$ ($K\neq3n$) transitions.
