diff --git a/internal/registry/model_registry.go b/internal/registry/model_registry.go
index cc679941..dba10d9d 100644
--- a/internal/registry/model_registry.go
+++ b/internal/registry/model_registry.go
@@ -105,10 +105,12 @@ func (r *ModelRegistry) RegisterClient(clientID, clientProvider string, models [
 	seen := make(map[string]struct{})
 	modelIDs := make([]string, 0, len(models))
 	newModels := make(map[string]*ModelInfo, len(models))
+	newCounts := make(map[string]int, len(models))
 	for _, model := range models {
 		if model == nil || model.ID == "" {
 			continue
 		}
+		newCounts[model.ID]++
 		if _, exists := seen[model.ID]; exists {
 			continue
 		}
@@ -148,36 +150,45 @@ func (r *ModelRegistry) RegisterClient(clientID, clientProvider string, models [
 		return
 	}
 
-	oldSet := make(map[string]struct{}, len(oldModels))
+	oldCounts := make(map[string]int, len(oldModels))
 	for _, id := range oldModels {
-		oldSet[id] = struct{}{}
+		oldCounts[id]++
 	}
 
 	added := make([]string, 0)
-	removed := make([]string, 0)
 	for _, id := range modelIDs {
-		if _, exists := oldSet[id]; !exists {
+		if oldCounts[id] == 0 {
 			added = append(added, id)
 		}
 	}
-	for _, id := range oldModels {
-		if _, exists := newModels[id]; !exists {
+
+	removed := make([]string, 0)
+	for id := range oldCounts {
+		if newCounts[id] == 0 {
 			removed = append(removed, id)
 		}
 	}
 
 	// Handle provider change for overlapping models before modifications.
 	if providerChanged && oldProvider != "" {
-		for _, id := range modelIDs {
-			if _, existed := oldSet[id]; !existed {
+		for id, newCount := range newCounts {
+			if newCount == 0 {
 				continue
 			}
+			oldCount := oldCounts[id]
+			if oldCount == 0 {
+				continue
+			}
+			toRemove := newCount
+			if oldCount < toRemove {
+				toRemove = oldCount
+			}
 			if reg, ok := r.models[id]; ok && reg.Providers != nil {
 				if count, okProv := reg.Providers[oldProvider]; okProv {
-					if count <= 1 {
+					if count <= toRemove {
 						delete(reg.Providers, oldProvider)
 					} else {
-						reg.Providers[oldProvider] = count - 1
+						reg.Providers[oldProvider] = count - toRemove
 					}
 				}
 			}
@@ -186,13 +197,34 @@ func (r *ModelRegistry) RegisterClient(clientID, clientProvider string, models [
 
 	// Apply removals first to keep counters accurate.
 	for _, id := range removed {
-		r.removeModelRegistration(clientID, id, oldProvider, now)
+		oldCount := oldCounts[id]
+		for i := 0; i < oldCount; i++ {
+			r.removeModelRegistration(clientID, id, oldProvider, now)
+		}
+	}
+
+	for id, oldCount := range oldCounts {
+		newCount := newCounts[id]
+		if newCount == 0 || oldCount <= newCount {
+			continue
+		}
+		overage := oldCount - newCount
+		for i := 0; i < overage; i++ {
+			r.removeModelRegistration(clientID, id, oldProvider, now)
+		}
 	}
 
 	// Apply additions.
-	for _, id := range added {
+	for id, newCount := range newCounts {
+		oldCount := oldCounts[id]
+		if newCount <= oldCount {
+			continue
+		}
 		model := newModels[id]
-		r.addModelRegistration(id, provider, model, now)
+		diff := newCount - oldCount
+		for i := 0; i < diff; i++ {
+			r.addModelRegistration(id, provider, model, now)
+		}
 	}
 
 	// Update metadata for models that remain associated with the client.
@@ -209,10 +241,17 @@ func (r *ModelRegistry) RegisterClient(clientID, clientProvider string, models [
 				if _, newlyAdded := addedSet[id]; newlyAdded {
 					continue
 				}
+				overlapCount := newCounts[id]
+				if oldCount := oldCounts[id]; oldCount < overlapCount {
+					overlapCount = oldCount
+				}
+				if overlapCount <= 0 {
+					continue
+				}
 				if reg.Providers == nil {
 					reg.Providers = make(map[string]int)
 				}
-				reg.Providers[provider]++
+				reg.Providers[provider] += overlapCount
 			}
 		}
 	}