diff --git a/changelogs/fragments/20240810-rds_instance-performance_insights_kms_key_id.yml b/changelogs/fragments/20240810-rds_instance-performance_insights_kms_key_id.yml
new file mode 100644
index 00000000000..f1870df3d17
--- /dev/null
+++ b/changelogs/fragments/20240810-rds_instance-performance_insights_kms_key_id.yml
@@ -0,0 +1,3 @@
+---
+minor_changes:
+  - rds_instance - snake case for parameter ``performance_insights_kms_key_id`` was incorrect according to boto documentation (https://github.com/ansible-collections/amazon.aws/pull/2163).
\ No newline at end of file
diff --git a/plugins/module_utils/rds.py b/plugins/module_utils/rds.py
index be34032c35d..148c81f8a8d 100644
--- a/plugins/module_utils/rds.py
+++ b/plugins/module_utils/rds.py
@@ -531,7 +531,7 @@ def get_snapshot(client, snapshot_identifier: str, snapshot_type: str, convert_t
         snapshot = snapshots[0]
 
     if snapshot and convert_tags:
-        snapshot["Tags"] = boto3_tag_list_to_ansible_dict(snapshot.pop("TagList"))
+        snapshot["Tags"] = boto3_tag_list_to_ansible_dict(snapshot.pop("TagList", None))
 
     return snapshot
 
@@ -576,8 +576,15 @@ def arg_spec_to_rds_params(options_dict: Dict[str, Any]) -> Dict[str, Any]:
         has_processor_features = True
         processor_features = options_dict.pop("processor_features")
     camel_options = snake_dict_to_camel_dict(options_dict, capitalize_first=True)
+    aws_replace_keys = (
+        ("Db", "DB"),
+        ("Iam", "IAM"),
+        ("Az", "AZ"),
+        ("Ca", "CA"),
+        ("PerformanceInsightsKmsKeyId", "PerformanceInsightsKMSKeyId"),
+    )
     for key in list(camel_options.keys()):
-        for old, new in (("Db", "DB"), ("Iam", "IAM"), ("Az", "AZ"), ("Ca", "CA")):
+        for old, new in aws_replace_keys:
             if old in key:
                 camel_options[key.replace(old, new)] = camel_options.pop(key)
     camel_options["Tags"] = tags
diff --git a/plugins/modules/rds_instance.py b/plugins/modules/rds_instance.py
index d6246b5dfaf..cd899f774ee 100644
--- a/plugins/modules/rds_instance.py
+++ b/plugins/modules/rds_instance.py
@@ -1142,6 +1142,14 @@ def get_options_with_changing_values(client, module: AnsibleAWSModule, parameter
                     # must be always specified when changing iops
                     parameters["AllocatedStorage"] = new_allocated_storage
 
+    instance_performance_insights_kms_key_id = instance.get("PerformanceInsightsKMSKeyId")
+    if instance_performance_insights_kms_key_id == module.params.get(
+        "performance_insights_kms_key_id"
+    ) or instance_performance_insights_kms_key_id.split("/")[-1] == module.params.get(
+        "performance_insights_kms_key_id"
+    ):
+        parameters.pop("PerformanceInsightsKMSKeyId", None)
+
     if parameters.get("NewDBInstanceIdentifier") and instance.get("PendingModifiedValues", {}).get(
         "DBInstanceIdentifier"
     ):