diff --git a/.changes/next-release/bugfix-DLMEMR-99146.json b/.changes/next-release/bugfix-DLMEMR-99146.json
new file mode 100644
index 000000000000..812d7fcc21e0
--- /dev/null
+++ b/.changes/next-release/bugfix-DLMEMR-99146.json
@@ -0,0 +1,5 @@
+{
+  "type": "bugfix",
+  "category": "DLM, EMR",
+  "description": "Dynamically load AWS partition information using partitions.json instead of hardcoded region mappings. Affects ``dlm create-default-role``, ``emr create-default-roles``, ``emr-containers create-role-associations``, and ``emr-containers update-role-trust-policy`` commands."
+}
diff --git a/awscli/customizations/utils.py b/awscli/customizations/utils.py
index fd135a8714a2..8761b32bd1fa 100644
--- a/awscli/customizations/utils.py
+++ b/awscli/customizations/utils.py
@@ -21,6 +21,8 @@
 import xml
 
 from botocore.exceptions import ClientError
+from botocore.loaders import Loader
+from botocore.endpoint_provider import RuleSetStandardLibary
 
 from awscli.customizations.exceptions import ParamValidationError
 
@@ -207,13 +209,11 @@ def uni_print(statement, out_file=None):
 
 def get_policy_arn_suffix(region):
     """Method to return region value as expected by policy arn"""
-    region_string = region.lower()
-    if region_string.startswith("cn-"):
-        return "aws-cn"
-    elif region_string.startswith("us-gov"):
-        return "aws-us-gov"
-    else:
-        return "aws"
+    loader = Loader()
+    partitions_data = loader.load_data('partitions')
+    rule_lib = RuleSetStandardLibary(partitions_data)
+    partition_result = rule_lib.aws_partition(region.lower())
+    return partition_result['name']
 
 
 def get_shape_doc_overview(shape):
diff --git a/tests/unit/customizations/test_utils.py b/tests/unit/customizations/test_utils.py
index f6c5a2bed071..19cdbc6d2f10 100644
--- a/tests/unit/customizations/test_utils.py
+++ b/tests/unit/customizations/test_utils.py
@@ -263,6 +263,7 @@ def test_get_policy_arn_suffix(self):
         self.assertEqual("aws", utils.get_policy_arn_suffix("us-east-1"))
         self.assertEqual("aws", utils.get_policy_arn_suffix("sa-east-1"))
         self.assertEqual("aws", utils.get_policy_arn_suffix("ap-south-1"))
+        self.assertEqual("aws-eusc", utils.get_policy_arn_suffix("eusc-de-east-1"))
 
 
 class TestGetShapeDocOverview(unittest.TestCase):