diff --git a/React/Modules/RCTUIManager.m b/React/Modules/RCTUIManager.m
index 1d7ac52a941..dff752077e9 100644
--- a/React/Modules/RCTUIManager.m
+++ b/React/Modules/RCTUIManager.m
@@ -808,6 +808,7 @@ RCT_EXPORT_METHOD(removeRootView:(nonnull NSNumber *)rootReactTag)
 RCT_EXPORT_METHOD(replaceExistingNonRootView:(nonnull NSNumber *)reactTag
                   withView:(nonnull NSNumber *)newReactTag)
 {
+  RCTLogWarn(@"RCTUIManager.replaceExistingNonRootView method is deprecated and it will not be implemented in newer versions of RN (Fabric) - T47686450");
   RCTShadowView *shadowView = _shadowViewRegistry[reactTag];
   RCTAssert(shadowView != nil, @"shadowView (for ID %@) not found", reactTag);
 
diff --git a/ReactAndroid/src/main/java/com/facebook/react/uimanager/UIManagerModule.java b/ReactAndroid/src/main/java/com/facebook/react/uimanager/UIManagerModule.java
index 478dc2b4070..c13b9e26ed3 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/uimanager/UIManagerModule.java
+++ b/ReactAndroid/src/main/java/com/facebook/react/uimanager/UIManagerModule.java
@@ -544,8 +544,11 @@ public class UIManagerModule extends ReactContextBaseJavaModule
    * Replaces the View specified by oldTag with the View specified by newTag within oldTag's parent.
    * This resolves to a simple {@link #manageChildren} call, but React doesn't have enough info in
    * JS to formulate it itself.
+   *
+   * @deprecated This method will not be available in Fabric UIManager.
    */
   @ReactMethod
+  @Deprecated
   public void replaceExistingNonRootView(int oldTag, int newTag) {
     mUIImplementation.replaceExistingNonRootView(oldTag, newTag);
   }