diff --git a/tipg/database.py b/tipg/database.py
index 09ac9287..7c7f1708 100644
--- a/tipg/database.py
+++ b/tipg/database.py
@@ -1,12 +1,9 @@
 """tipg.db: database events."""
 
-import functools
-import os
 import pathlib
 from importlib.resources import files as resources_files
-from typing import List, Optional, Union
+from typing import List, Optional
 
-import boto3
 import orjson
 from buildpg import asyncpg
 
@@ -18,26 +15,6 @@
 DB_CATALOG_FILE = resources_files(__package__) / "sql" / "dbcatalog.sql"
 
 
-def get_rds_token(
-    host: Union[str, None],
-    port: Union[int, None],
-    user: Union[str, None],
-    region: Union[str, None],
-) -> str:
-    """Get RDS token for IAM auth"""
-    logger.debug(
-        f"Retrieving RDS IAM token with host: {host}, port: {port}, user: {user}, region: {region}"
-    )
-    rds_client = boto3.client("rds")
-    token = rds_client.generate_db_auth_token(
-        DBHostname=host,
-        Port=port,
-        DBUsername=user,
-        Region=region or rds_client.meta.region_name,
-    )
-    return token
-
-
 class connection_factory:
     """Connection creation."""
 
@@ -111,15 +88,7 @@ async def connect_to_db(
         schemas, tipg_schema, user_sql_files, skip_sql_execution
     )
 
-    if os.environ.get("IAM_AUTH_ENABLED") == "TRUE":
-        kwargs["password"] = functools.partial(
-            get_rds_token,
-            settings.postgres_host,
-            settings.postgres_port,
-            settings.postgres_user,
-            settings.aws_region,
-        )
-        kwargs["ssl"] = "require"
+    merged_pool_kwargs = {**settings.pool_kwargs, **(kwargs or {})}
 
     app.state.pool = await asyncpg.create_pool_b(
         str(settings.database_url),
@@ -128,7 +97,7 @@ async def connect_to_db(
         max_queries=settings.db_max_queries,
         max_inactive_connection_lifetime=settings.db_max_inactive_conn_lifetime,
         init=con_init,
-        **kwargs,
+        **merged_pool_kwargs,
     )
 
 
diff --git a/tipg/settings.py b/tipg/settings.py
index f118012b..88e245da 100644
--- a/tipg/settings.py
+++ b/tipg/settings.py
@@ -4,6 +4,7 @@
 import pathlib
 from typing import Any, Dict, List, Optional
 
+import boto3
 from pydantic import (
     BaseModel,
     DirectoryPath,
@@ -151,6 +152,33 @@ class PostgresSettings(BaseSettings):
 
     model_config = {"env_file": ".env", "extra": "ignore"}
 
+    def get_rds_token(self) -> str:
+        """Generate an RDS IAM token for authentication."""
+        rds_client = boto3.client("rds")
+        token = rds_client.generate_db_auth_token(
+            DBHostname=self.postgres_host,
+            Port=self.postgres_port,
+            DBUsername=self.postgres_user,
+            Region=self.aws_region or rds_client.meta.region_name,
+        )
+        return token
+
+    @property
+    def pool_kwargs(self) -> Dict[str, Any]:
+        """
+        Build the default connection parameters for the pool.
+
+        If IAM auth is enabled, use a dynamic password callable (bound to get_rds_token).
+        Otherwise, use a static password if provided.
+        """
+        kwargs: Dict[str, Any] = {}
+        if self.iam_auth_enabled:
+            kwargs["password"] = self.get_rds_token
+            kwargs["ssl"] = "require"
+        elif self.postgres_pass:
+            kwargs["password"] = self.postgres_pass
+        return kwargs
+
     # https://github.com/tiangolo/full-stack-fastapi-postgresql/blob/master/%7B%7Bcookiecutter.project_slug%7D%7D/backend/app/app/core/config.py#L42
     @field_validator("database_url", mode="before")
     def assemble_db_connection(