diff --git a/CHANGES.rst b/CHANGES.rst
index acca6242b..a9284d8eb 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -68,6 +68,11 @@ refpix
 
 - Add initial reference pixel correction step implementation. [#704]
 
+saturation
+----------
+
+- Add read_pattern argument to flag_saturated_pixels. [#836]
+
 general
 -------
 
diff --git a/docs/roman/saturation/description.rst b/docs/roman/saturation/description.rst
index 1a88e0cb1..0bef3c625 100644
--- a/docs/roman/saturation/description.rst
+++ b/docs/roman/saturation/description.rst
@@ -8,7 +8,8 @@ below the A/D floor if they have a value of zero DN.
 
 This step examines the data group-by-group, comparing the pixel values in the data array with defined
 saturation thresholds for each pixel. When it finds a pixel value in a given
-group that is above the saturation threshold (high saturation), it sets the
+group that is above the saturation threshold (high saturation) times a
+dilution factor, it sets the
 "SATURATED" flag in the corresponding location of the "groupdq" array in the
 science exposure.  When it finds a pixel in a given group that has a zero or
 negative value (below  the A/D floor), it sets the "AD_FLOOR" and "DO_NOT_USE"
@@ -24,3 +25,13 @@ of 65535 and hence will only be flagged as saturated if the pixel reaches that
 hard limit in at least one group. The "NO_SAT_CHECK" flag is propagated to the
 PIXELDQ array in the output science data to indicate which pixels fall into
 this category.
+
+The "dilution factor" is intended to account for the fact that Roman
+downlinks resultants to the ground, which are usually averages over
+several reads.  The saturation threshold corresponds to the number of
+counts at which a detector pixel saturates.  Because a resultant is
+the average of a number of reads, later reads in a resultant can
+saturate, but if earlier reads are unsaturated, the value of the
+resultant can fall under the saturation threshold.  The dilution
+factor varies resultant-by-resultant and is given by
+:math:`<t>/max(t)` for all times :math:`t` entering a resultant.
diff --git a/romancal/saturation/saturation.py b/romancal/saturation/saturation.py
index 9ad6725e9..547325c9b 100644
--- a/romancal/saturation/saturation.py
+++ b/romancal/saturation/saturation.py
@@ -49,7 +49,15 @@ def flag_saturation(input_model, ref_model):
     # The third variable is the processed ZEROFRAME, which is not
     # used in romancal, so is always None.
     gdq_new, pdq_new, _ = flag_saturated_pixels(
-        data, gdq, pdq, sat_thresh, sat_dq, ATOD_LIMIT, dqflags.pixel, n_pix_grow_sat=0
+        data,
+        gdq,
+        pdq,
+        sat_thresh,
+        sat_dq,
+        ATOD_LIMIT,
+        dqflags.pixel,
+        n_pix_grow_sat=0,
+        read_pattern=input_model.meta.exposure.read_pattern,
     )
 
     # Save the flags in the output GROUPDQ array
diff --git a/romancal/saturation/tests/test_saturation.py b/romancal/saturation/tests/test_saturation.py
index f9d22ae4b..240b17137 100644
--- a/romancal/saturation/tests/test_saturation.py
+++ b/romancal/saturation/tests/test_saturation.py
@@ -41,6 +41,49 @@ def test_basic_saturation_flagging(setup_wfi_datamodels):
     assert np.all(output.groupdq[satindex:, 5, 5] == dqflags.group["SATURATED"])
 
 
+def test_read_pattern_saturation_flagging(setup_wfi_datamodels):
+    """Check that the saturation threshold varies depending on how the reads
+    are allocated into resultants."""
+
+    # Create inputs, and data and saturation models
+    ngroups = 5
+    nrows = 20
+    ncols = 20
+    satvalue = 60000
+    ramp, satmap = setup_wfi_datamodels(ngroups, nrows, ncols)
+
+    # Add ramp values up to the saturation limit
+    ramp.data[0, 5, 5] = 0 * ramp.data.unit
+    ramp.data[1, 5, 5] = 20000 * ramp.data.unit
+    ramp.data[2, 5, 5] = 40000 * ramp.data.unit
+    ramp.data[3, 5, 5] = 60000 * ramp.data.unit  # Signal reaches saturation limit
+    ramp.data[4, 5, 5] = 62000 * ramp.data.unit
+
+    # set read_pattern to have many reads in the third resultant, so that
+    # its mean exposure time is much smaller than its last read time
+    # (in this case, the ratio is 13 / 20).
+    # This means that the effective saturation for the third resultant
+    # is 60000 * 13 / 20 = 39000 and the third resultant should be marked
+    # saturated.
+    ramp.meta.exposure.read_pattern = [
+        [1],
+        [2],
+        [3, 4, 5, 6, 7, 8, 9, 10],
+        [11],
+        [12],
+        [13],
+    ]
+
+    # Set saturation value in the saturation model
+    satmap.data[5, 5] = satvalue * satmap.data.unit
+
+    # Run the pipeline
+    output = flag_saturation(ramp, satmap)
+
+    # Make sure that groups after the third get flagged
+    assert np.all(output.groupdq[2:, 5, 5] == dqflags.group["SATURATED"])
+
+
 def test_ad_floor_flagging(setup_wfi_datamodels):
     """Check that the ad_floor flag is set when a pixel value is zero or
     negative."""