diff --git a/CHANGES.rst b/CHANGES.rst
index fb9684e1..d4465a47 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -21,6 +21,9 @@ Other
 - Add ``grating`` keyword to JWST ``barshadow`` ref file schema to match
   parkeys on crds [#260]
 
+- Add ``average_dark_current`` in both scalar keyword and array extension
+  options to ``DarkModel`` and ``MIRIDarkModel``. Add the array extension
+  to the ``RampModel``, for tracking the average dark current. [#265]
 
 1.9.1 (2024-01-25)
 ==================
diff --git a/src/stdatamodels/jwst/datamodels/schemas/dark.schema.yaml b/src/stdatamodels/jwst/datamodels/schemas/dark.schema.yaml
index db4b37eb..c7de7dbe 100644
--- a/src/stdatamodels/jwst/datamodels/schemas/dark.schema.yaml
+++ b/src/stdatamodels/jwst/datamodels/schemas/dark.schema.yaml
@@ -14,6 +14,7 @@ allOf:
 - $ref: keyword_groupgap.schema
 - $ref: keyword_gainfact.schema
 - $ref: keyword_psubarray.schema
+- $ref: keyword_darkcurrent.schema
 - $ref: subarray.schema
 - type: object
   properties:
@@ -35,4 +36,10 @@ allOf:
       default: 0.0
       ndim: 3
       datatype: float32
+    average_dark_current:
+      title: Average dark current
+      fits_hdu: AVDRKCUR
+      default: 0.0
+      ndim: 2
+      datatype: float32
 - $ref: dq_def.schema
diff --git a/src/stdatamodels/jwst/datamodels/schemas/darkMIRI.schema.yaml b/src/stdatamodels/jwst/datamodels/schemas/darkMIRI.schema.yaml
index 68c079b0..019870d3 100644
--- a/src/stdatamodels/jwst/datamodels/schemas/darkMIRI.schema.yaml
+++ b/src/stdatamodels/jwst/datamodels/schemas/darkMIRI.schema.yaml
@@ -11,6 +11,7 @@ allOf:
 - $ref: keyword_nframes.schema
 - $ref: keyword_ngroups.schema
 - $ref: keyword_groupgap.schema
+- $ref: keyword_darkcurrent.schema
 - $ref: subarray.schema
 - type: object
   properties:
@@ -32,4 +33,10 @@ allOf:
       default: 0.0
       ndim: 4
       datatype: float32
+    average_dark_current:
+      title: Average dark current
+      fits_hdu: AVDRKCUR
+      default: 0.0
+      ndim: 2
+      datatype: float32
 - $ref: dq_def.schema
diff --git a/src/stdatamodels/jwst/datamodels/schemas/keyword_darkcurrent.schema.yaml b/src/stdatamodels/jwst/datamodels/schemas/keyword_darkcurrent.schema.yaml
new file mode 100644
index 00000000..b037a758
--- /dev/null
+++ b/src/stdatamodels/jwst/datamodels/schemas/keyword_darkcurrent.schema.yaml
@@ -0,0 +1,17 @@
+%YAML 1.1
+---
+$schema: "http://stsci.edu/schemas/fits-schema/fits-schema"
+id: "http://stsci.edu/schemas/jwst_datamodel/keyword_darkcurrent.schema"
+type: object
+properties:
+  meta:
+    type: object
+    properties:
+      exposure:
+        type: object
+        properties:
+          average_dark_current:
+            title: Average dark current
+            type: number
+            default: 0.0
+            fits_keyword: AVDRKCUR
\ No newline at end of file
diff --git a/src/stdatamodels/jwst/datamodels/schemas/ramp.schema.yaml b/src/stdatamodels/jwst/datamodels/schemas/ramp.schema.yaml
index f428adbf..bc3625d8 100644
--- a/src/stdatamodels/jwst/datamodels/schemas/ramp.schema.yaml
+++ b/src/stdatamodels/jwst/datamodels/schemas/ramp.schema.yaml
@@ -44,6 +44,12 @@ allOf:
       default: 0.0
       ndim: 4
       datatype: float32
+    average_dark_current:
+      title: Average dark current
+      fits_hdu: AVDRKCUR
+      default: 0.0
+      ndim: 2
+      datatype: float32
 - $ref: group.schema
 - $ref: int_times.schema
 - $ref: msatargacq.schema
\ No newline at end of file