diff --git a/planetstack/model_policies/model_policy_Site.py b/planetstack/model_policies/model_policy_Site.py
new file mode 100644
index 0000000..a49c868
--- /dev/null
+++ b/planetstack/model_policies/model_policy_Site.py
@@ -0,0 +1,12 @@
+from core.models import *
+
+def handle(site):
+    # make sure site has a ControllerSite record for each controller
+    ctrl_sites = ControllerSite.objects.filter(site=site)
+    existing_controllers = [cs.controller for cs in ctrl_sites]
+
+    all_controllers = Controller.objects.all()
+    for ctrl in all_controllers:
+        if ctrl not in existing_controllers:
+            ctrl_site = ControllerSite(controller=ctrl, site=site)
+            ctrl_site.save()