diff --git a/gstlal-inspiral/bin/gstlal_inspiral_add_p_of_ifos_given_horizon b/gstlal-inspiral/bin/gstlal_inspiral_add_p_of_ifos_given_horizon
new file mode 100644
index 0000000000000000000000000000000000000000..f413ad5c3b79c16e04d950014b58164f04d4e22c
--- /dev/null
+++ b/gstlal-inspiral/bin/gstlal_inspiral_add_p_of_ifos_given_horizon
@@ -0,0 +1,27 @@
+#!/usr/bin/env python
+#
+# Copyright (C) 2019 Leo Tsukada
+#
+# This program is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation; either version 2 of the License, or (at your
+# option) any later version.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
+# Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+import sys
+from gstlal.stats import inspiral_extrinsics
+
+# Read in and combine all of the input files
+instruments = "".join(sorted(sys.argv[1].split(",")))
+files = sys.argv[2:]
+PofI = inspiral_extrinsics.p_of_instruments_given_horizons.from_hdf5(files[0], files[1:])
+
+PofI.to_hdf5("%s_p_of_instruments_given_H_d.h5" % instruments)