diff --git a/rules/typescript/identifier-includes-check.toml b/rules/typescript/identifier-includes-check.toml
new file mode 100644
index 0000000..3605a8c
--- /dev/null
+++ b/rules/typescript/identifier-includes-check.toml
@@ -0,0 +1,110 @@
+[rule]
+id = "ts-identifier-includes-check"
+languages = ["typescript", "javascript"]
+category = "rbac"
+confidence = "high"
+description = "Role or group collection inclusion check on a bare identifier (e.g., userGroups.includes(\"admin\"))"
+query = """
+(call_expression
+  function: (member_expression
+    object: (identifier) @collection
+    property: (property_identifier) @method)
+  arguments: (arguments
+    (string) @role_value)
+) @match
+"""
+
+[rule.predicates.collection]
+match = "^(roles?|groups?|userRoles|userGroups)$"
+
+[rule.predicates.method]
+match = "^(includes|indexOf|contains|some|has)$"
+
+[rule.rego_template]
+template = """
+default allow := false
+
+allow if {
+    "{{role_value}}" in input.user.roles
+}
+"""
+
+
+[rule.cedar_template]
+template = """
+permit (
+    principal,
+    action,
+    resource
+)
+when {
+    principal.roles.contains("{{role_value}}")
+};
+"""
+
+[[rule.tests]]
+input = """
+if (userGroups.includes("manager")) {
+  allow();
+}
+"""
+expect_match = true
+
+[[rule.tests]]
+input = """
+if (groups.indexOf("admin") > -1) {
+  allow();
+}
+"""
+expect_match = true
+
+[[rule.tests]]
+input = """
+if (permissions.includes("write")) {
+  allow();
+}
+"""
+expect_match = false
+
+[[rule.tests]]
+input = """
+if (claims.has("customer")) {
+  allow();
+}
+"""
+expect_match = false
+language = "javascript"
+
+[[rule.tests]]
+input = """
+if (scope.includes("read:billing")) {
+  allow();
+}
+"""
+expect_match = false
+language = "javascript"
+
+[[rule.tests]]
+input = """
+if (scopes.has("write:billing")) {
+  allow();
+}
+"""
+expect_match = false
+language = "javascript"
+
+[[rule.tests]]
+input = """
+if (cache.has("key")) {
+  hit();
+}
+"""
+expect_match = false
+
+[[rule.tests]]
+input = """
+if (tags.includes("foo")) {
+  filter();
+}
+"""
+expect_match = false
diff --git a/src/rules/embedded.rs b/src/rules/embedded.rs
index ef50d17..1400d83 100644
--- a/src/rules/embedded.rs
+++ b/src/rules/embedded.rs
@@ -12,6 +12,10 @@ const EMBEDDED_RULES: &[(&str, &str)] = &[
         "role-includes-check",
         include_str!("../../rules/typescript/role-includes-check.toml"),
     ),
+    (
+        "identifier-includes-check",
+        include_str!("../../rules/typescript/identifier-includes-check.toml"),
+    ),
     (
         "has-role-call",
         include_str!("../../rules/typescript/has-role-call.toml"),
diff --git a/src/scanner/matcher.rs b/src/scanner/matcher.rs
index 1cfad9e..0f753d7 100644
--- a/src/scanner/matcher.rs
+++ b/src/scanner/matcher.rs
@@ -483,6 +483,36 @@ public IActionResult Reports() => Ok();"#,
         assert!(!findings.is_empty());
     }
 
+    #[test]
+    fn identifier_includes_check_is_role_shaped_only() {
+        let findings = parse_and_match(
+            r#"if (userGroups.includes("manager")) { allow(); }"#,
+            include_str!("../../rules/typescript/identifier-includes-check.toml"),
+        );
+
+        assert_eq!(findings.len(), 1);
+        assert_eq!(findings[0].category, crate::types::AuthCategory::Rbac);
+        let rego = findings[0].rego_stub.as_deref().unwrap();
+        assert!(
+            rego.contains(r#""manager" in input.user.roles"#),
+            "rego should use a role membership check; got: {rego}"
+        );
+        let cedar = findings[0].cedar_stub.as_deref().unwrap();
+        assert!(
+            cedar.contains(r#"principal.roles.contains("manager")"#),
+            "cedar should use a role membership check; got: {cedar}"
+        );
+
+        let permission_findings = parse_and_match(
+            r#"if (permissions.includes("write")) { allow(); }"#,
+            include_str!("../../rules/typescript/identifier-includes-check.toml"),
+        );
+        assert!(
+            permission_findings.is_empty(),
+            "bare permission collections need a permission-shaped rule"
+        );
+    }
+
     // -- Java rule tests --
 
     fn parse_and_match_java(source: &str, rule_toml: &str) -> Vec<Finding> {