diff --git a/software/software/agent_hooks.py b/software/software/agent_hooks.py
index c04e5f03..ebd47388 100644
--- a/software/software/agent_hooks.py
+++ b/software/software/agent_hooks.py
@@ -970,6 +970,38 @@ class FixedEtcMergeRollBackHook(FixedEtcMergeHook):
         LOG.info("FixedEtcMergeRollBackHook finished.")
 
 
+class OOTDriverHook(BaseHook):
+    """
+    Hook to remove out-of-tree driver kernel parameters during upgrade.
+    """
+
+    PARAM_NAME = "out-of-tree-drivers"
+
+    def _remove_kernel_param(self):
+        try:
+            cmd = (
+                "python /usr/local/bin/puppet-update-grub-env.py "
+                f"--remove-kernelparams {self.PARAM_NAME}"
+            )
+            subprocess.run(cmd, shell=True, check=True, capture_output=True)
+            LOG.info("Removed kernel parameter: %s", self.PARAM_NAME)
+        except subprocess.CalledProcessError as e:
+            LOG.exception(
+                "Failed to remove kernel parameter %s: %s",
+                self.PARAM_NAME, str(e)
+            )
+
+    def run(self):
+        if self._from_release == "25.09":
+            # Upgrade path: remove kernel param
+            self._remove_kernel_param()
+            LOG.info("Upgrade OOTDriverHook completed.")
+        else:
+            LOG.info(
+                "OOTDriverHook: nothing to do for this release transition."
+            )
+
+
 class HookManager(object):
     """
     Object to manage the execution of agent hooks
@@ -982,6 +1014,7 @@ class HookManager(object):
     AGENT_HOOKS = {
         MAJOR_RELEASE_UPGRADE: [
             CreateUSMUpgradeInProgressFlag,
+            OOTDriverHook,
             EtcMerger,
             CopyPxeFilesHook,
             ReconfigureKernelHook,
diff --git a/software/upgrade-scripts/04-remove-out-of-tree-service-parameter.py b/software/upgrade-scripts/04-remove-out-of-tree-service-parameter.py
new file mode 100644
index 00000000..ba010f21
--- /dev/null
+++ b/software/upgrade-scripts/04-remove-out-of-tree-service-parameter.py
@@ -0,0 +1,122 @@
+#!/usr/bin/env python
+# Copyright (c) 2025 Wind River Systems, Inc.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+# This script removes the out_of_tree_drivers service parameter
+# from sysinv DB during upgrade from 25.09 to 26.03.
+#
+
+import logging
+import sys
+
+from packaging import version
+import psycopg2
+
+from software.utilities.utils import configure_logging
+
+DEFAULT_POSTGRES_PORT = 5432
+LOG = logging.getLogger('main_logger')
+
+PARAM_NAME = "out_of_tree_drivers"
+PARAM_SERVICE = "platform"
+PARAM_SECTION = "kernel"
+
+
+def main():
+    action = None
+    from_release = None
+    to_release = None
+    postgres_port = DEFAULT_POSTGRES_PORT
+    arg = 1
+    while arg < len(sys.argv):
+        if arg == 1:
+            from_release = sys.argv[arg]
+        elif arg == 2:
+            to_release = sys.argv[arg]
+        elif arg == 3:
+            action = sys.argv[arg]
+        elif arg == 4:
+            postgres_port = sys.argv[arg]
+        else:
+            print("Invalid option %s." % sys.argv[arg])
+            return 1
+        arg += 1
+
+    configure_logging()
+    LOG.info(
+        "%s invoked from_release=%s to_release=%s action=%s",
+        sys.argv[0], from_release, to_release, action
+    )
+
+    res = 0
+    to_release_version = version.Version(to_release)
+    target_version = version.Version("26.03")
+
+    # Only remove service param on migrate to 26.03
+    if action == 'migrate' and to_release_version == target_version:
+        try:
+            conn = psycopg2.connect(
+                "dbname=sysinv user=postgres port=%s" % postgres_port
+            )
+            remove_service_param(conn)
+            conn.close()
+        except Exception as e:
+            LOG.exception("Error removing service parameter: %s", e)
+            res = 1
+
+    return res
+
+
+def remove_service_param(conn):
+    """Remove out_of_tree_drivers service parameter from sysinv DB."""
+    query = (
+        "SELECT uuid, value FROM service_parameter "
+        "WHERE name='%s' AND service='%s' AND section='%s';"
+        % (PARAM_NAME, PARAM_SERVICE, PARAM_SECTION)
+    )
+    rows = db_query(conn, query)
+    if not rows:
+        LOG.info(
+            "No service parameter '%s' found. Nothing to delete.", PARAM_NAME
+        )
+        return
+
+    for uuid, value in rows:
+        LOG.info(
+            "Deleting service parameter '%s' (uuid=%s, value=%s)",
+            PARAM_NAME, uuid, value
+        )
+        delete_query = (
+            "DELETE FROM service_parameter WHERE uuid='%s';" % uuid
+        )
+        db_update(conn, delete_query)
+
+    LOG.info(
+        "Service parameter '%s' removed successfully.", PARAM_NAME
+    )
+
+
+def db_query(conn, query):
+    """Execute a read-only query and return results."""
+    result = []
+    with conn.cursor() as cur:
+        cur.execute(query)
+        for rec in cur:
+            result.append(rec)
+    return result
+
+
+def db_update(conn, query):
+    """Execute a write query and commit changes."""
+    with conn.cursor() as cur:
+        cur.execute(query)
+    conn.commit()
+
+
+if __name__ == "__main__":
+    try:
+        sys.exit(main())
+    except Exception as e:
+        LOG.error("An error occurred: %s", e)
+        raise