diff --git a/comfy/model_patcher.py b/comfy/model_patcher.py
index 087b0fbfa..2bb363fab 100644
--- a/comfy/model_patcher.py
+++ b/comfy/model_patcher.py
@@ -1692,16 +1692,27 @@ class ModelPatcherDynamic(ModelPatcher):
             self.model.dynamic_vbars = {}
         if not hasattr(self.model, "dynamic_pins"):
             self.model.dynamic_pins = {}
-        if self.load_device not in self.model.dynamic_pins:
-            self.model.dynamic_pins[self.load_device] = {
+        self.register_load_device(self.load_device)
+        self.non_dynamic_delegate_model = None
+        assert load_device is not None
+
+    def register_load_device(self, device):
+        """Ensure dynamic_pins has an entry for *device*.
+
+        Called from __init__ and also from any code that retargets an
+        already-constructed patcher to a new load_device (e.g. the
+        Select{Model,CLIP,VAE}Device selector nodes); without this entry
+        partially_unload_ram() raises KeyError when it tries to read the
+        per-device pin state.
+        """
+        if device not in self.model.dynamic_pins:
+            self.model.dynamic_pins[device] = {
                 "weights": (comfy_aimdo.host_buffer.HostBuffer(0, 0, 0), [], [-1], [0]),
                 "patches": (comfy_aimdo.host_buffer.HostBuffer(0, 0, 0), [], [-1], [0]),
                 "hostbufs_initialized": False,
                 "failed": False,
                 "active": False,
             }
-        self.non_dynamic_delegate_model = None
-        assert load_device is not None
 
     def is_dynamic(self):
         return True
diff --git a/comfy_extras/nodes_multigpu.py b/comfy_extras/nodes_multigpu.py
index 9e03c56f0..df701af56 100644
--- a/comfy_extras/nodes_multigpu.py
+++ b/comfy_extras/nodes_multigpu.py
@@ -90,6 +90,8 @@ class SelectModelDeviceNode(io.ComfyNode):
         model.load_device = resolved
         if resolved.type == "cpu":
             model.offload_device = resolved
+        if hasattr(model, "register_load_device"):
+            model.register_load_device(resolved)
         return io.NodeOutput(model)
 
 
@@ -135,6 +137,8 @@ class SelectCLIPDeviceNode(io.ComfyNode):
         clip.patcher.load_device = resolved
         if resolved.type == "cpu":
             clip.patcher.offload_device = resolved
+        if hasattr(clip.patcher, "register_load_device"):
+            clip.patcher.register_load_device(resolved)
         return io.NodeOutput(clip)
 
 
@@ -185,6 +189,8 @@ class SelectVAEDeviceNode(io.ComfyNode):
         vae.device = resolved
         vae.patcher.load_device = resolved
         vae.patcher.offload_device = comfy.model_management.vae_offload_device()
+        if hasattr(vae.patcher, "register_load_device"):
+            vae.patcher.register_load_device(resolved)
         return io.NodeOutput(vae)