diff --git a/internal/tests/pytests/wrappers/ensemble_stat/test_ensemble_stat_wrapper.py b/internal/tests/pytests/wrappers/ensemble_stat/test_ensemble_stat_wrapper.py
index aad6656e24..3737e8ec72 100644
--- a/internal/tests/pytests/wrappers/ensemble_stat/test_ensemble_stat_wrapper.py
+++ b/internal/tests/pytests/wrappers/ensemble_stat/test_ensemble_stat_wrapper.py
@@ -444,10 +444,16 @@ def test_handle_climo_file_variables(metplus_config, config_overrides,
          {'METPLUS_INTERP_DICT': 'interp = {shape = CIRCLE;}'}),
 
         ({'ENSEMBLE_STAT_INTERP_TYPE_METHOD': 'BILIN', },
-         {'METPLUS_INTERP_DICT': 'interp = {type = {method = BILIN;}}'}),
+         {'METPLUS_INTERP_DICT': 'interp = {type = {method = [BILIN];}}'}),
 
         ({'ENSEMBLE_STAT_INTERP_TYPE_WIDTH': '2', },
-         {'METPLUS_INTERP_DICT': 'interp = {type = {width = 2;}}'}),
+         {'METPLUS_INTERP_DICT': 'interp = {type = {width = [2];}}'}),
+        # multiple interp type methods
+        ({'ENSEMBLE_STAT_INTERP_TYPE_METHOD': 'BILIN, NEAREST', },
+         {'METPLUS_INTERP_DICT': 'interp = {type = {method = [BILIN, NEAREST];}}'}),
+        # multiple interp type methods
+        ({'ENSEMBLE_STAT_INTERP_TYPE_WIDTH': '2,3', },
+         {'METPLUS_INTERP_DICT': 'interp = {type = {width = [2, 3];}}'}),
 
         ({
              'ENSEMBLE_STAT_INTERP_VLD_THRESH': '0.8',
@@ -457,7 +463,7 @@ def test_handle_climo_file_variables(metplus_config, config_overrides,
          },
          {'METPLUS_INTERP_DICT': ('interp = {vld_thresh = 0.8;'
                                   'shape = CIRCLE;'
-                                  'type = {method = BILIN;width = 2;}}')}),
+                                  'type = {method = [BILIN];width = [2];}}')}),
 
         ({'ENSEMBLE_STAT_CLIMO_MEAN_FILE_NAME': '/some/climo_mean/file.txt', },
          {'METPLUS_CLIMO_MEAN_DICT': ('climo_mean = {file_name = '
diff --git a/internal/tests/pytests/wrappers/grid_stat/test_grid_stat_wrapper.py b/internal/tests/pytests/wrappers/grid_stat/test_grid_stat_wrapper.py
index 280103c68e..458c515e3c 100644
--- a/internal/tests/pytests/wrappers/grid_stat/test_grid_stat_wrapper.py
+++ b/internal/tests/pytests/wrappers/grid_stat/test_grid_stat_wrapper.py
@@ -462,10 +462,16 @@ def test_handle_climo_file_variables(metplus_config, config_overrides,
          {'METPLUS_INTERP_DICT': 'interp = {shape = CIRCLE;}'}),
 
         ({'GRID_STAT_INTERP_TYPE_METHOD': 'BILIN', },
-         {'METPLUS_INTERP_DICT': 'interp = {type = {method = BILIN;}}'}),
+         {'METPLUS_INTERP_DICT': 'interp = {type = {method = [BILIN];}}'}),
 
         ({'GRID_STAT_INTERP_TYPE_WIDTH': '2', },
-         {'METPLUS_INTERP_DICT': 'interp = {type = {width = 2;}}'}),
+         {'METPLUS_INTERP_DICT': 'interp = {type = {width = [2];}}'}),
+        # multiple interp type methods
+        ({'GRID_STAT_INTERP_TYPE_METHOD': 'BILIN, NEAREST', },
+         {'METPLUS_INTERP_DICT': 'interp = {type = {method = [BILIN, NEAREST];}}'}),
+        # multiple interp type methods
+        ({'GRID_STAT_INTERP_TYPE_WIDTH': '2,3', },
+         {'METPLUS_INTERP_DICT': 'interp = {type = {width = [2, 3];}}'}),
 
         ({
              'GRID_STAT_INTERP_FIELD': 'NONE',
@@ -476,7 +482,7 @@ def test_handle_climo_file_variables(metplus_config, config_overrides,
          },
          {'METPLUS_INTERP_DICT': ('interp = {vld_thresh = 0.8;'
                                   'shape = CIRCLE;'
-                                  'type = {method = BILIN;width = 2;}'
+                                  'type = {method = [BILIN];width = [2];}'
                                   'field = NONE;}')}),
 
         ({'GRID_STAT_CLIMO_MEAN_FILE_NAME': '/some/climo_mean/file.txt', },
diff --git a/internal/tests/pytests/wrappers/point_stat/test_point_stat_wrapper.py b/internal/tests/pytests/wrappers/point_stat/test_point_stat_wrapper.py
index 2e7ef0ef16..a384e1b725 100755
--- a/internal/tests/pytests/wrappers/point_stat/test_point_stat_wrapper.py
+++ b/internal/tests/pytests/wrappers/point_stat/test_point_stat_wrapper.py
@@ -304,10 +304,16 @@ def test_met_dictionary_in_var_options(metplus_config):
          {'METPLUS_INTERP_DICT': 'interp = {shape = SQUARE;}'}),
 
         ({'POINT_STAT_INTERP_TYPE_METHOD': 'BILIN', },
-         {'METPLUS_INTERP_DICT': 'interp = {type = {method = BILIN;}}'}),
+         {'METPLUS_INTERP_DICT': 'interp = {type = {method = [BILIN];}}'}),
 
         ({'POINT_STAT_INTERP_TYPE_WIDTH': '2', },
-         {'METPLUS_INTERP_DICT': 'interp = {type = {width = 2;}}'}),
+         {'METPLUS_INTERP_DICT': 'interp = {type = {width = [2];}}'}),
+        # multiple interp type methods
+        ({'POINT_STAT_INTERP_TYPE_METHOD': 'BILIN, NEAREST', },
+         {'METPLUS_INTERP_DICT': 'interp = {type = {method = [BILIN, NEAREST];}}'}),
+        # multiple interp type methods
+        ({'POINT_STAT_INTERP_TYPE_WIDTH': '2,3', },
+         {'METPLUS_INTERP_DICT': 'interp = {type = {width = [2, 3];}}'}),
 
         ({
              'POINT_STAT_INTERP_VLD_THRESH': '0.5',
@@ -318,7 +324,7 @@ def test_met_dictionary_in_var_options(metplus_config):
          {
              'METPLUS_INTERP_DICT': ('interp = {'
                                      'vld_thresh = 0.5;shape = SQUARE;'
-                                     'type = {method = BILIN;width = 2;}}')}),
+                                     'type = {method = [BILIN];width = [2];}}')}),
 
         ({'POINT_STAT_CLIMO_MEAN_FILE_NAME': '/some/climo_mean/file.txt', },
          {'METPLUS_CLIMO_MEAN_DICT': ('climo_mean = {file_name = '
diff --git a/metplus/wrappers/compare_gridded_wrapper.py b/metplus/wrappers/compare_gridded_wrapper.py
index 69f6bc5cb0..3631b1d55f 100755
--- a/metplus/wrappers/compare_gridded_wrapper.py
+++ b/metplus/wrappers/compare_gridded_wrapper.py
@@ -365,8 +365,8 @@ def handle_interp_dict(self, uses_field=False):
             'vld_thresh': 'float',
             'shape': ('string', 'remove_quotes'),
             'type': ('dict', None, {
-                'method': ('string', 'remove_quotes'),
-                'width': 'int',
+                'method': ('list', 'remove_quotes'),
+                'width': ('list', 'remove_quotes'),
             }),
         }
         if uses_field: