diff --git a/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/15_plus/alter_index_no_depends.sql b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/15_plus/alter_index_no_depends.sql
index eb0be343a58..f05567f540d 100644
--- a/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/15_plus/alter_index_no_depends.sql
+++ b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/15_plus/alter_index_no_depends.sql
@@ -7,7 +7,7 @@ CREATE UNIQUE INDEX IF NOT EXISTS "Idx_$%{}[]()&*^!@""'`\/#"
     (id ASC NULLS LAST, name COLLATE pg_catalog."POSIX" text_pattern_ops ASC NULLS LAST)
     INCLUDE(name, id)
     NULLS NOT DISTINCT
-    WITH (fillfactor=10, deduplicate_items=False)
+    WITH (fillfactor=10, deduplicate_items=false)
 
     WHERE id < 100;
 
diff --git a/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/15_plus/create_index_with_ext.sql b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/15_plus/create_index_with_ext.sql
index d46299198e6..a4cbb386da0 100644
--- a/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/15_plus/create_index_with_ext.sql
+++ b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/15_plus/create_index_with_ext.sql
@@ -7,7 +7,7 @@ CREATE UNIQUE INDEX IF NOT EXISTS "Idx_$%{}[]()&*^!@""'`\/#"
     (id ASC NULLS LAST, name COLLATE pg_catalog."POSIX" text_pattern_ops ASC NULLS LAST)
     INCLUDE(name, id)
     NULLS NOT DISTINCT
-    WITH (fillfactor=10, deduplicate_items=False)
+    WITH (fillfactor=10, deduplicate_items=false)
 
     WHERE id < 100;
 
diff --git a/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/default/alter_index_no_depends.sql b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/default/alter_index_no_depends.sql
index 8284142636a..11d57949e01 100644
--- a/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/default/alter_index_no_depends.sql
+++ b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/default/alter_index_no_depends.sql
@@ -6,7 +6,7 @@ CREATE UNIQUE INDEX IF NOT EXISTS "Idx_$%{}[]()&*^!@""'`\/#"
     ON public.test_table_for_indexes USING btree
     (id ASC NULLS LAST, name COLLATE pg_catalog."POSIX" text_pattern_ops ASC NULLS LAST)
     INCLUDE(name, id)
-    WITH (fillfactor=10, deduplicate_items=False)
+    WITH (fillfactor=10, deduplicate_items=false)
 
     WHERE id < 100;
 
diff --git a/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/default/create_btree_asc_null_first.sql b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/default/create_btree_asc_null_first.sql
index 706e32ff508..cb153b22160 100644
--- a/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/default/create_btree_asc_null_first.sql
+++ b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/default/create_btree_asc_null_first.sql
@@ -6,7 +6,7 @@ CREATE UNIQUE INDEX IF NOT EXISTS "Idx_$%{}[]()&*^!@""'`\/#"
     ON public.test_table_for_indexes USING btree
     (id ASC NULLS FIRST, name COLLATE pg_catalog."POSIX" text_pattern_ops ASC NULLS FIRST)
     INCLUDE(name, id)
-    WITH (fillfactor=10, deduplicate_items=False)
+    WITH (fillfactor=10, deduplicate_items=false)
 
     WHERE id < 100;
 
diff --git a/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/default/create_btree_asc_null_last.sql b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/default/create_btree_asc_null_last.sql
index c69bf1ae964..5e5fe39c288 100644
--- a/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/default/create_btree_asc_null_last.sql
+++ b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/default/create_btree_asc_null_last.sql
@@ -6,7 +6,7 @@ CREATE UNIQUE INDEX IF NOT EXISTS "Idx_$%{}[]()&*^!@""'`\/#"
     ON public.test_table_for_indexes USING btree
     (id ASC NULLS LAST, name COLLATE pg_catalog."POSIX" text_pattern_ops ASC NULLS LAST)
     INCLUDE(name, id)
-    WITH (fillfactor=10, deduplicate_items=False)
+    WITH (fillfactor=10, deduplicate_items=false)
 
     WHERE id < 100;
 
diff --git a/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/default/create_btree_desc_null_last.sql b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/default/create_btree_desc_null_last.sql
index c31cc5d03d4..2a5aa9180ff 100644
--- a/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/default/create_btree_desc_null_last.sql
+++ b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/default/create_btree_desc_null_last.sql
@@ -6,7 +6,7 @@ CREATE UNIQUE INDEX IF NOT EXISTS "Idx_$%{}[]()&*^!@""'`\/#"
     ON public.test_table_for_indexes USING btree
     (id DESC NULLS LAST, name COLLATE pg_catalog."POSIX" text_pattern_ops DESC NULLS LAST)
     INCLUDE(name, id)
-    WITH (fillfactor=10, deduplicate_items=False)
+    WITH (fillfactor=10, deduplicate_items=false)
 
     WHERE id < 100;
 
diff --git a/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/default/create_index_with_ext.sql b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/default/create_index_with_ext.sql
index 27bddad38df..18cc4ec48ce 100644
--- a/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/default/create_index_with_ext.sql
+++ b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/default/create_index_with_ext.sql
@@ -6,7 +6,7 @@ CREATE UNIQUE INDEX IF NOT EXISTS "Idx_$%{}[]()&*^!@""'`\/#"
     ON public.test_table_for_indexes USING btree
     (id ASC NULLS LAST, name COLLATE pg_catalog."POSIX" text_pattern_ops ASC NULLS LAST)
     INCLUDE(name, id)
-    WITH (fillfactor=10, deduplicate_items=False)
+    WITH (fillfactor=10, deduplicate_items=false)
 
     WHERE id < 100;
 
diff --git a/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/test_indexes_sql_options.py b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/test_indexes_sql_options.py
new file mode 100644
index 00000000000..d42e14bdf10
--- /dev/null
+++ b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/tests/test_indexes_sql_options.py
@@ -0,0 +1,175 @@
+##########################################################################
+#
+# pgAdmin 4 - PostgreSQL Tools
+#
+# Copyright (C) 2013 - 2026, The pgAdmin Development Team
+# This software is released under the PostgreSQL Licence
+#
+##########################################################################
+
+"""Reverse engineered index SQL must preserve opclass options (e.g.
+gist_trgm_ops(siglen=32)) and every storage parameter found in the
+catalog, including ones pgAdmin does not know about.
+
+https://github.com/pgadmin-org/pgadmin4/issues/9625
+"""
+
+import re
+import uuid
+
+from pgadmin.browser.server_groups.servers.databases.schemas.tables.columns. \
+    tests import utils as columns_utils
+from pgadmin.browser.server_groups.servers.databases.schemas.tables.tests \
+    import utils as tables_utils
+from pgadmin.browser.server_groups.servers.databases.schemas.tests import \
+    utils as schema_utils
+from pgadmin.browser.server_groups.servers.databases.tests import utils as \
+    database_utils
+from pgadmin.utils.route import BaseTestGenerator
+from regression import parent_node_dict
+from regression.python_test_utils import test_utils as utils
+
+
+class IndexSqlOptionsTestCase(BaseTestGenerator):
+    """This class tests sql generated for indexes having opclass options
+    or storage parameters unknown to pgAdmin."""
+
+    url = "/browser/index/sql/"
+    scenarios = utils.generate_scenarios("index_sql_options", {
+        "index_sql_options": [{
+            "name": "Index SQL keeps opclass options and all reloptions",
+            "is_positive_test": True,
+            "inventory_data": {},
+            "test_data": {},
+            "mocking_required": False,
+            "mock_data": {},
+            "expected_data": {
+                "status_code": 200,
+                "error_msg": None,
+                "test_result_data": {}
+            },
+            "is_list": False
+        }]
+    })
+
+    def setUp(self):
+        super().setUp()
+        self.db_name = parent_node_dict["database"][-1]["db_name"]
+        schema_info = parent_node_dict["schema"][-1]
+        self.server_id = schema_info["server_id"]
+        self.db_id = schema_info["db_id"]
+        db_con = database_utils.connect_database(self, utils.SERVER_GROUP,
+                                                 self.server_id, self.db_id)
+        if not db_con['data']["connected"]:
+            raise Exception("Could not connect to database to add a table.")
+        self.schema_id = schema_info["schema_id"]
+        self.schema_name = schema_info["schema_name"]
+        schema_response = schema_utils.verify_schemas(self.server,
+                                                      self.db_name,
+                                                      self.schema_name)
+        if not schema_response:
+            raise Exception("Could not find the schema to add a table.")
+        self.table_name = "table_index_options_%s" % (str(uuid.uuid4())[1:8])
+        self.table_id = tables_utils.create_table(self.server, self.db_name,
+                                                  self.schema_name,
+                                                  self.table_name)
+        self.column_name = "content"
+        columns_utils.create_column(self.server, self.db_name,
+                                    self.schema_name, self.table_name,
+                                    self.column_name, 'text')
+
+        # Create the indexes with plain SQL: the index dialog supports
+        # neither opclass options nor arbitrary storage parameters, which
+        # is exactly what this test is about.
+        self.opclass_index_name = "idx_opclass_options_%s" % (
+            str(uuid.uuid4())[1:8])
+        self.relopts_index_name = "idx_all_reloptions_%s" % (
+            str(uuid.uuid4())[1:8])
+        connection = utils.get_db_connection(self.db_name,
+                                             self.server['username'],
+                                             self.server['db_password'],
+                                             self.server['host'],
+                                             self.server['port'])
+        old_isolation_level = connection.isolation_level
+        utils.set_isolation_level(connection, 0)
+        pg_cursor = connection.cursor()
+        pg_cursor.execute("CREATE EXTENSION IF NOT EXISTS pg_trgm")
+        pg_cursor.execute(
+            'ALTER TABLE {0}.{1} ADD COLUMN search_vector tsvector'.format(
+                self.schema_name, self.table_name))
+        pg_cursor.execute(
+            'CREATE INDEX {0} ON {1}.{2} USING GIST '
+            '({3} gist_trgm_ops(siglen=32))'.format(
+                self.opclass_index_name, self.schema_name, self.table_name,
+                self.column_name))
+        pg_cursor.execute(
+            'CREATE INDEX {0} ON {1}.{2} USING btree ({3}) '
+            'WITH (fillfactor=70, '
+            'vacuum_cleanup_index_scale_factor=0.5)'.format(
+                self.relopts_index_name, self.schema_name, self.table_name,
+                self.column_name))
+        self.default_opclass_index_name = "idx_def_opclass_options_%s" % (
+            str(uuid.uuid4())[1:8])
+        pg_cursor.execute(
+            'CREATE INDEX {0} ON {1}.{2} USING GIST '
+            '(search_vector tsvector_ops(siglen=64))'.format(
+                self.default_opclass_index_name, self.schema_name,
+                self.table_name))
+        pg_cursor.execute(
+            "SELECT cls.oid FROM pg_catalog.pg_class cls "
+            "JOIN pg_catalog.pg_namespace nsp ON nsp.oid = cls.relnamespace "
+            "WHERE cls.relkind = 'i' AND nsp.nspname = %s "
+            "AND cls.relname = ANY(%s)",
+            (self.schema_name,
+             [self.opclass_index_name, self.relopts_index_name,
+              self.default_opclass_index_name]))
+        self.index_ids = [row[0] for row in pg_cursor.fetchall()]
+        utils.set_isolation_level(connection, old_isolation_level)
+        connection.close()
+        if len(self.index_ids) != 3:
+            raise Exception("Could not create the test indexes.")
+
+    def get_index_sql(self, index_id):
+        response = self.tester.get(
+            "{0}{1}/{2}/{3}/{4}/{5}/{6}".format(self.url, utils.SERVER_GROUP,
+                                                self.server_id, self.db_id,
+                                                self.schema_id, self.table_id,
+                                                index_id),
+            follow_redirects=True)
+        self.assertEqual(response.status_code, 200)
+        resp_sql = response.data.decode('unicode_escape')
+        if resp_sql.startswith('"') and resp_sql.endswith('"'):
+            resp_sql = resp_sql[1:-1]
+        # Collapse whitespace so assertions do not depend on template
+        # line breaks.
+        return re.sub(r'\s+', ' ', resp_sql)
+
+    def runTest(self):
+        if self.is_positive_test:
+            sql_by_index = dict(
+                (idx, self.get_index_sql(idx)) for idx in self.index_ids)
+            opclass_sql = None
+            relopts_sql = None
+            for idx, sql in sql_by_index.items():
+                if self.opclass_index_name in sql:
+                    opclass_sql = sql
+                if self.relopts_index_name in sql:
+                    relopts_sql = sql
+            self.assertIsNotNone(opclass_sql)
+            self.assertIsNotNone(relopts_sql)
+            self.assertIn('gist_trgm_ops(siglen=32)', opclass_sql)
+            # Options on the default opclass still require the opclass
+            # name to be rendered, otherwise the options are lost.
+            default_sql = None
+            for idx, sql in sql_by_index.items():
+                if self.default_opclass_index_name in sql:
+                    default_sql = sql
+            self.assertIsNotNone(default_sql)
+            self.assertIn('tsvector_ops(siglen=64)', default_sql)
+            self.assertIn('fillfactor=70', relopts_sql)
+            self.assertIn('vacuum_cleanup_index_scale_factor=0.5',
+                          relopts_sql)
+
+    def tearDown(self):
+        # Disconnect the database
+        database_utils.disconnect_database(self, self.server_id, self.db_id)
diff --git a/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/utils.py b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/utils.py
index db6444f4c04..b9c5db2c27a 100644
--- a/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/utils.py
+++ b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/indexes/utils.py
@@ -129,6 +129,17 @@ def get_column_details(conn, idx, data, mode='properties', template_path=None):
             'statistics': row['statistics']
         }
 
+        # Preserve any opclass options (e.g. gist_trgm_ops(siglen=32)) in
+        # the generated SQL. Only when creating SQL: the properties
+        # dialog expects the plain opclass name. #9625
+        if mode == 'create' and row['attoptions']:
+            # A default opclass has opcname=None, but the name must still
+            # be rendered for the options to survive.
+            opclass = row['opcname'] or row['opclassname']
+            if opclass:
+                cols_data['op_class'] = "{0}({1})".format(
+                    opclass, ', '.join(row['attoptions']))
+
         # ASC/DESC and NULLS works only with btree indexes
         if 'amname' in data and data['amname'] == 'btree':
             cols_data['sort_order'] = False
@@ -334,11 +345,12 @@ def get_reverse_engineered_sql(conn, **kwargs):
     data['table'] = table
     data["storage_parameters"] = {}
 
-    storage_params = get_storage_params(data['amname'])
-
-    for param in storage_params:
-        if (param in data) and (data[param] is not None):
-            data["storage_parameters"].update({param: data[param]})
+    # Use the raw reloptions from the catalog so that every storage
+    # parameter is preserved, including ones pgAdmin doesn't know about
+    # (e.g. options of extension index access methods). #9625
+    for option in data.get('reloptions') or []:
+        key, _, value = option.partition('=')
+        data["storage_parameters"][key] = value
 
     # Add column details for current index
     data = get_column_details(conn, idx, data, 'create')
diff --git a/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/templates/indexes/sql/15_plus/properties.sql b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/templates/indexes/sql/15_plus/properties.sql
index 2fce4aa3612..b735040a757 100644
--- a/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/templates/indexes/sql/15_plus/properties.sql
+++ b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/templates/indexes/sql/15_plus/properties.sql
@@ -53,7 +53,8 @@ SELECT DISTINCT ON (cls.relname)
     substring(array_to_string(cls.reloptions, ',') FROM 'buffering=([a-z]*)') AS buffering,
     substring(array_to_string(cls.reloptions, ',') FROM 'fastupdate=([a-z]*)')::boolean AS fastupdate,
     substring(array_to_string(cls.reloptions, ',') FROM 'autosummarize=([a-z]*)')::boolean AS autosummarize,
-    substring(array_to_string(cls.reloptions, ',') FROM 'lists=([0-9]*)')::int AS lists
+    substring(array_to_string(cls.reloptions, ',') FROM 'lists=([0-9]*)')::int AS lists,
+    cls.reloptions
     {% if datlastsysoid %}
         , (cls.oid <= {{ datlastsysoid }}::oid) AS is_sys_idx
     {% endif %}
diff --git a/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/templates/indexes/sql/default/column_details.sql b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/templates/indexes/sql/default/column_details.sql
index cc53e6877c3..3a4529d1de9 100644
--- a/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/templates/indexes/sql/default/column_details.sql
+++ b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/templates/indexes/sql/default/column_details.sql
@@ -11,6 +11,8 @@ SELECT
     pg_catalog.pg_get_indexdef(i.indexrelid, i.attnum, true) as attdef,
     CASE WHEN pg_catalog.pg_get_indexdef(i.indexrelid, i.attnum, true) = pg_catalog.quote_ident(a.attname) THEN FALSE ELSE TRUE END AS is_exp,
     a.attstattarget as statistics,
+    a.attoptions AS attoptions,
+    o.opcname AS opclassname,
     CASE WHEN (o.opcdefault = FALSE) THEN o.opcname ELSE null END AS opcname,
     op.oprname AS oprname,
 	CASE WHEN length(nspc.nspname::text) > 0 AND length(coll.collname::text) > 0  THEN
diff --git a/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/templates/indexes/sql/default/properties.sql b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/templates/indexes/sql/default/properties.sql
index 00b6c69558c..a26afe2696c 100644
--- a/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/templates/indexes/sql/default/properties.sql
+++ b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/templates/indexes/sql/default/properties.sql
@@ -52,7 +52,8 @@ SELECT DISTINCT ON (cls.relname)
     substring(array_to_string(cls.reloptions, ',') FROM 'buffering=([a-z]*)') AS buffering,
     substring(array_to_string(cls.reloptions, ',') FROM 'fastupdate=([a-z]*)') AS fastupdate,
     substring(array_to_string(cls.reloptions, ',') FROM 'autosummarize=([a-z]*)')::boolean AS autosummarize,
-    substring(array_to_string(cls.reloptions, ',') FROM 'lists=([0-9]*)')::int AS lists
+    substring(array_to_string(cls.reloptions, ',') FROM 'lists=([0-9]*)')::int AS lists,
+    cls.reloptions
     {% if datlastsysoid %}
         , (cls.oid <= {{ datlastsysoid }}::oid) AS is_sys_idx
     {% endif %}