diff --git a/dbt/adapters/redshift/connections.py b/dbt/adapters/redshift/connections.py
index e46ea5d51..4a85d0021 100644
--- a/dbt/adapters/redshift/connections.py
+++ b/dbt/adapters/redshift/connections.py
@@ -37,7 +37,7 @@ def get_message(self) -> str:
 class RedshiftConnectionMethod(StrEnum):
     DATABASE = "database"
     IAM = "iam"
-    IAMR = "iamr"
+    IAM_ROLE = "iam_role"
 
 
 class UserSSLMode(StrEnum):
@@ -215,7 +215,7 @@ def connect():
                 raise FailedToConnectError("'user' field is required for 'iam' credentials")
 
             def connect():
-                logger.debug("Connecting to redshift with IAM based auth...")
+                logger.debug("Connecting to redshift with IAM User based auth...")
                 c = redshift_connector.connect(
                     iam=True,
                     db_user=self.credentials.user,
@@ -231,15 +231,18 @@ def connect():
                     c.cursor().execute("set role {}".format(self.credentials.role))
                 return c
 
-        elif method == RedshiftConnectionMethod.IAMR:
+        elif method == RedshiftConnectionMethod.IAM_ROLE:
             if not self.credentials.cluster_id and "serverless" not in self.credentials.host:
                 raise FailedToConnectError(
-                    "Failed to use IAM method. 'cluster_id' must be provided for provisioned cluster. "
+                    "Failed to use IAM Role method. 'cluster_id' must be provided for provisioned cluster. "
                     "'host' must be provided for serverless endpoint."
                 )
 
+            if self.credentials.user is None:
+                raise FailedToConnectError("'user' field is required for 'iam' credentials")
+
             def connect():
-                logger.debug("Connecting to redshift with IAM based auth...")
+                logger.debug("Connecting to redshift with IAM Role based auth...")
                 c = redshift_connector.connect(
                     iam=True,
                     cluster_identifier=self.credentials.cluster_id,
diff --git a/dbt/include/redshift/profile_template.yml b/dbt/include/redshift/profile_template.yml
index 5f6b0a91a..d78356923 100644
--- a/dbt/include/redshift/profile_template.yml
+++ b/dbt/include/redshift/profile_template.yml
@@ -15,8 +15,8 @@ prompts:
         hide_input: true
     iam:
       _fixed_method: iam
-    iamr:
-      _fixed_method: iamr
+    iam_role:
+      _fixed_method: iam_role
   dbname:
     hint: 'default database that dbt will build objects in'
   schema: