diff --git a/romancal/regtest/test_catalog.py b/romancal/regtest/test_catalog.py
index c3c055b30..de1a13cf2 100644
--- a/romancal/regtest/test_catalog.py
+++ b/romancal/regtest/test_catalog.py
@@ -3,18 +3,33 @@
 import asdf
 import pytest
 
+from romancal.source_catalog.source_catalog_step import SourceCatalogStep
 from romancal.stpipe import RomanStep
 
 # mark all tests in this module
 pytestmark = [pytest.mark.bigdata, pytest.mark.soctests]
 
+input_filenames = [
+    "r0099101001001001001_F158_visit_i2d.asdf",
+    "r0000101001001001001_0001_wfi01_cal.asdf",
+]
+
+field_list = [
+    "ra_centroid",  # DMS374 positions on ICRF
+    "dec_centroid",  # DMS374 positions on ICRF
+    "aper_total_flux",  # DMS375 fluxes
+    "aper30_flux",  # DMS399 aperture fluxes
+    "aper50_flux",  # DMS399 aperture fluxes
+    "aper70_flux",  # DMS399 aperture fluxes
+    "is_extended",  # DMS376 type of source
+    "aper_total_flux_err",  # DMS386 flux uncertainties
+    "flags",  # DMS387 dq_flags
+]
+
 
 @pytest.fixture(
     scope="module",
-    params=[
-        "r0099101001001001001_F158_visit_i2d.asdf",
-        "r0000101001001001001_0001_wfi01_cal.asdf",
-    ],
+    params=input_filenames,
     ids=["L3", "L2"],
 )
 def run_source_catalog(rtdata_module, request):
@@ -50,14 +65,72 @@ def fields(catalog):
 
 @pytest.mark.parametrize(
     "field",
-    (
-        "ra_centroid",  # DMS374 positions on ICRF
-        "dec_centroid",  # DMS374 positions on ICRF
-        "aper_total_flux",  # DMS375 fluxes
-        "is_extended",  # DMS376 type of source
-        "aper_total_flux_err",  # DMS386 flux uncertainties
-        "flags",  # DMS387 dq_flags
-    ),
+    field_list,
 )
 def test_has_field(fields, field):
     assert field in fields
+
+
+def test_deblend_source_catalog(rtdata_module):
+    rtdata = rtdata_module
+    inputfn = input_filenames[1]  # use L2 image; could have picked either one
+    rtdata.get_data(f"WFI/image/{inputfn}")
+    rtdata.input = inputfn
+
+    step = SourceCatalogStep()
+
+    outputfn1 = inputfn.rsplit("_", 1)[0] + "_cat.asdf"
+    args = [
+        "romancal.step.SourceCatalogStep",
+        rtdata.input,
+        "--deblend",
+        "False",
+        "--output_file",
+        outputfn1,
+    ]
+    RomanStep.from_cmdline(args)
+    outputfn2 = inputfn.rsplit("_", 1)[0] + "_deblend_cat.asdf"
+    rtdata.output = outputfn2
+    args = [
+        "romancal.step.SourceCatalogStep",
+        rtdata.input,
+        "--deblend",
+        "True",
+        "--output_file",
+        outputfn2,
+    ]
+    RomanStep.from_cmdline(args)
+
+    af1 = asdf.open(outputfn1)
+    af2 = asdf.open(outputfn2)
+    nsrc1 = len(af1["roman"]["source_catalog"])
+    nsrc2 = len(af2["roman"]["source_catalog"])
+    step.log.info(
+        "DMS393: Deblended source catalog contains more sources "
+        f"({nsrc2}) than undeblended ({nsrc1})?  "
+        + ("PASS" if nsrc2 > nsrc1 else "FAIL")
+    )
+    assert nsrc2 > nsrc1
+
+
+def test_kernel_detection(rtdata_module):
+    rtdata = rtdata_module
+    inputfn = input_filenames[1]  # use L2 image; could have picked either one
+    rtdata.get_data(f"WFI/image/{inputfn}")
+    rtdata.input = inputfn
+    outputfn = inputfn.rsplit("_", 1)[0] + "_kernel10_cat.asdf"
+    step = SourceCatalogStep()
+    args = [
+        "romancal.step.SourceCatalogStep",
+        rtdata.input,
+        "--kernel_fwhm",
+        "10",
+        "--output_file",
+        outputfn,
+    ]
+    RomanStep.from_cmdline(args)
+    af = asdf.open(outputfn)
+    fields = af["roman"]["source_catalog"].dtype.names
+    for field in field_list:
+        assert field in field_list
+    step.log.info("DMS391: Used alternative kernel to detect sources.  PASS")
diff --git a/romancal/scripts/make_regtestdata.sh b/romancal/scripts/make_regtestdata.sh
index a6031dd35..6160f18fb 100644
--- a/romancal/scripts/make_regtestdata.sh
+++ b/romancal/scripts/make_regtestdata.sh
@@ -186,11 +186,6 @@ cp L3_regtest_asn.json $outdir/roman-pipeline/dev/WFI/image/
 cp ${l3name}_i2d.asdf $outdir/roman-pipeline/dev/WFI/image/
 cp ${l3name}_i2d.asdf $outdir/roman-pipeline/dev/truth/WFI/image/
 
-# L3 catalog
-strun romancal.step.SourceCatalogStep ${l3name}_i2d.asdf
-cp ${l3name}_cat.asdf $outdir/roman-pipeline/dev/truth/WFI/image/
-
-
 l3name="r0099101001001001001_r274dp63x31y81_prompt_F158"
 asn_from_list r0000101001001001001_0001_wfi01_cal.asdf r0000101001001001001_0002_wfi01_cal.asdf r0000101001001001001_0003_wfi01_cal.asdf -o L3_mosaic_asn.json --product-name $l3name --target r274dp63x31y81
 strun roman_mos L3_mosaic_asn.json
@@ -202,11 +197,20 @@ cp ${l3name}_i2d.asdf $outdir/roman-pipeline/dev/truth/WFI/image/
 strun romancal.step.SourceCatalogStep ${l3name}_i2d.asdf
 cp ${l3name}_cat.asdf $outdir/roman-pipeline/dev/truth/WFI/image/
 
-
 # L2 catalog
 strun romancal.step.SourceCatalogStep r0000101001001001001_0001_wfi01_cal.asdf
 cp r0000101001001001001_0001_wfi01_cat.asdf $outdir/roman-pipeline/dev/truth/WFI/image/
+cp r0000101001001001001_0001_wfi01_segm.asdf $outdir/roman-pipeline/dev/truth/WFI/image/
+
+# L2 catalog with larger kernel
+strun romancal.step.SourceCatalogStep r0000101001001001001_0001_wfi01_cal.asdf --kernel_fwhm 10 --output_file r0000101001001001001_0001_wfi01_kernel10_cat.asdf
+cp r0000101001001001001_0001_wfi01_kernel10_cat.asdf $outdir/roman-pipeline-dev/truth/WFI/image
+cp r0000101001001001001_0001_wfi01_kernel10_segm.asdf $outdir/roman-pipeline-dev/truth/WFI/image
 
+# L2 catalog using deblending
+strun romancal.step.SourceCatalogStep r0000101001001001001_0001_wfi01_cal.asdf --deblend True --output_file r0000101001001001001_0001_wfi01_deblend_cat.asdf
+cp r0000101001001001001_0001_wfi01_deblend_cat.asdf $outdir/roman-pipeline-dev/truth/WFI/image
+cp r0000101001001001001_0001_wfi01_deblend_segm.asdf $outdir/roman-pipeline-dev/truth/WFI/image
 
 l3name="r0099101001001001001_F158_visit_r274dp63x31y81"
 asn_from_list --product-name=$l3name r0000101001001001001_0001_wfi01_cal.asdf r0000101001001001001_0002_wfi01_cal.asdf r0000101001001001001_0003_wfi01_cal.asdf -o L3_m1_asn.json
diff --git a/romancal/tests/dms_requirement_tests.json b/romancal/tests/dms_requirement_tests.json
index 2d6588492..526ef447b 100644
--- a/romancal/tests/dms_requirement_tests.json
+++ b/romancal/tests/dms_requirement_tests.json
@@ -108,6 +108,15 @@
   "DMS387": [
     "romancal.regtest.test_catalog.test_has_field"
   ],
+  "DMS391": [
+    "romancal.regtest.test_kernel_detection"
+  ],
+  "DMS393": [
+    "romancal.regtest.test_deblend_source_catalog"
+  ],
+  "DMS399": [
+    "romancal.regtest.test_catalog.test_has_field"
+  ],
   "DMS400": [
     "romancal.regtest.test_mos_pipeline.test_steps_ran",
     "romancal.regtest.test_mos_pipeline.test_added_background",