diff --git a/esphome/core/__init__.py b/esphome/core/__init__.py
index b63e4e3ad0..d0ceedfcbc 100644
--- a/esphome/core/__init__.py
+++ b/esphome/core/__init__.py
@@ -807,7 +807,12 @@ class EsphomeCore:
 
     @property
     def using_esp_idf(self):
-        return self.target_platform == PLATFORM_ESP32
+        _LOGGER.warning(
+            "CORE.using_esp_idf was deprecated in 2026.1, will change behavior in 2026.6. "
+            "ESP32 Arduino builds on top of ESP-IDF, so ESP-IDF features are available in both frameworks. "
+            "Use CORE.is_esp32 and/or CORE.using_arduino instead."
+        )
+        return self.target_framework == "esp-idf"
 
     @property
     def using_zephyr(self):