diff --git a/CHANGES.rst b/CHANGES.rst
index b23910940..37a25ca1c 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -1,3 +1,11 @@
+11.17.4 (2023-08-28)
+=====================
+
+JWST
+----
+
+- Added new rmap miri gain [#945]
+
 11.17.3 (2023-08-17)
 ====================
 
diff --git a/crds/jwst/specs/combined_specs.json b/crds/jwst/specs/combined_specs.json
index 2446f4dfb..1cfed0be5 100644
--- a/crds/jwst/specs/combined_specs.json
+++ b/crds/jwst/specs/combined_specs.json
@@ -1204,15 +1204,20 @@
             "instrument":"MIRI",
             "ld_tpn":"miri_gain_ld.tpn",
             "mapping":"REFERENCE",
-            "name":"jwst_miri_gain_0000.rmap",
+            "name":"miri_gain.rmap",
             "observatory":"JWST",
             "parkey":[
                 [
                     "META.INSTRUMENT.DETECTOR",
-                    "META.INSTRUMENT.FILTER"
+                    "META.INSTRUMENT.FILTER",
+                    "META.SUBARRAY.NAME"
+                ],
+                [
+                    "META.OBSERVATION.DATE",
+                    "META.OBSERVATION.TIME"
                 ]
             ],
-            "sha1sum":"09f1b655e8999a1be2ef3aea286e74fc0588738c",
+            "sha1sum":"898a158c3b13c23aa4cb6b2ac6ab12178b5834b1",
             "suffix":"gain",
             "text_descr":"Gain",
             "tpn":"miri_gain.tpn",
diff --git a/crds/jwst/specs/miri_gain.spec b/crds/jwst/specs/miri_gain.rmap
similarity index 62%
rename from crds/jwst/specs/miri_gain.spec
rename to crds/jwst/specs/miri_gain.rmap
index 9176c8601..0aef370cb 100644
--- a/crds/jwst/specs/miri_gain.spec
+++ b/crds/jwst/specs/miri_gain.rmap
@@ -1,14 +1,17 @@
-{
+header = {
     'derived_from' : 'cloning tool 0.05b (2013-04-12) used on 2013-10-04',
     'file_ext' : '.fits',
     'filekind' : 'GAIN',
     'filetype' : 'GAIN',
     'instrument' : 'MIRI',
     'mapping' : 'REFERENCE',
-    'name' : 'jwst_miri_gain_0000.rmap',
+    'name' : 'miri_gain.rmap',
     'observatory' : 'JWST',
-    'parkey' : (('META.INSTRUMENT.DETECTOR', 'META.INSTRUMENT.FILTER'),),
-    'sha1sum' : '09f1b655e8999a1be2ef3aea286e74fc0588738c',
+    'parkey' : (('META.INSTRUMENT.DETECTOR', 'META.INSTRUMENT.FILTER', 'META.SUBARRAY.NAME'), ('META.OBSERVATION.DATE', 'META.OBSERVATION.TIME')),
+    'sha1sum' : '898a158c3b13c23aa4cb6b2ac6ab12178b5834b1',
     'suffix' : 'gain',
     'text_descr' : 'Gain',
 }
+
+selector = Match({
+})