diff --git a/imap_processing/ialirt/l0/process_swe.py b/imap_processing/ialirt/l0/process_swe.py
index 6b9d2944f..3b56b9c51 100644
--- a/imap_processing/ialirt/l0/process_swe.py
+++ b/imap_processing/ialirt/l0/process_swe.py
@@ -475,7 +475,9 @@ def process_swe(accumulated_data: xr.Dataset, in_flight_cal_files: list) -> list
 
     # Get total full cycle data available for processing.
     # There are 60 packets in a set so (0, 59) is the range.
-    grouped_data = find_groups(accumulated_data, (0, 59), "swe_seq", "time_seconds")
+    grouped_data = find_groups(
+        accumulated_data, (0, 59), "swe_seq", "met", "swe_nom_flag"
+    )
     unique_groups = np.unique(grouped_data["group"])
     swe_data: list[dict] = []
     incomplete_groups = []
diff --git a/imap_processing/ialirt/utils/grouping.py b/imap_processing/ialirt/utils/grouping.py
index 27bf3fcbc..cb28193b6 100644
--- a/imap_processing/ialirt/utils/grouping.py
+++ b/imap_processing/ialirt/utils/grouping.py
@@ -8,7 +8,9 @@
 logger = logging.getLogger(__name__)
 
 
-def filter_valid_groups(grouped_data: xr.Dataset) -> xr.Dataset:
+def filter_valid_groups(
+    grouped_data: xr.Dataset, flag: str | None = None
+) -> xr.Dataset:
     """
     Filter out groups where `src_seq_ctr` diff are not 1.
 
@@ -16,6 +18,8 @@ def filter_valid_groups(grouped_data: xr.Dataset) -> xr.Dataset:
     ----------
     grouped_data : xr.Dataset
         Dataset with a "group" coordinate.
+    flag : str | None
+        Optional name of flag data variable.
 
     Returns
     -------
@@ -42,6 +46,12 @@ def filter_valid_groups(grouped_data: xr.Dataset) -> xr.Dataset:
         drop=True,
     )
 
+    if flag:
+        filtered_data = filtered_data.where(
+            filtered_data[flag] != 0,
+            drop=True,
+        )
+
     return filtered_data
 
 
@@ -50,6 +60,7 @@ def find_groups(
     sequence_range: tuple,
     sequence_name: str,
     time_name: str,
+    flag: str | None = None,
 ) -> xr.Dataset:
     """
     Group data based on time and sequence number values.
@@ -64,6 +75,8 @@ def find_groups(
         Name of the sequence variable.
     time_name : str
         Name of the time variable.
+    flag : str | None
+        Optional name of flag data variable.
 
     Returns
     -------
@@ -82,9 +95,14 @@ def find_groups(
 
     # Use sequence_range == 0 to define the beginning of the group.
     # Find time at this index and use it as the beginning time for the group.
-    start_times = sorted_data[time_name][
-        (sorted_data[sequence_name] == sequence_range[0])
-    ]
+    if flag:
+        start_times = sorted_data[time_name][
+            (sorted_data[sequence_name] == sequence_range[0]) & (sorted_data[flag] != 0)
+        ]
+    else:
+        start_times = sorted_data[time_name][
+            (sorted_data[sequence_name] == sequence_range[0])
+        ]
     # Use max sequence_range to define the end of the group.
     end_times = sorted_data[time_name][
         ([sorted_data[sequence_name] == sequence_range[-1]][-1])
@@ -115,6 +133,6 @@ def find_groups(
     grouped_data = grouped_data.assign_coords(group=("epoch", group_labels))
 
     # Filter out groups with non-sequential src_seq_ctr values.
-    filtered_data = filter_valid_groups(grouped_data)
+    filtered_data = filter_valid_groups(grouped_data, flag)
 
     return filtered_data
diff --git a/imap_processing/tests/ialirt/unit/test_process_swe.py b/imap_processing/tests/ialirt/unit/test_process_swe.py
index a9946deff..1df92c3fb 100644
--- a/imap_processing/tests/ialirt/unit/test_process_swe.py
+++ b/imap_processing/tests/ialirt/unit/test_process_swe.py
@@ -168,6 +168,7 @@ def test_process_spacecraft_packet(
         np.arange(462466219, 462466219 + n, dtype=np.uint32),
     )
     sc_xarray_data["swe_seq"] = ("epoch", np.arange(n) % 60)
+    sc_xarray_data["swe_nom_flag"] = xr.ones_like(sc_xarray_data["swe_nom_flag"])
 
     in_flight_cal_file = (
         imap_module_directory