diff --git a/telephony/java/android/telephony/TelephonyManager.java b/telephony/java/android/telephony/TelephonyManager.java
index d6cdaa6d8bc0c..f623649fb25ed 100644
--- a/telephony/java/android/telephony/TelephonyManager.java
+++ b/telephony/java/android/telephony/TelephonyManager.java
@@ -147,6 +147,10 @@ import java.util.regex.Pattern;
  * information unless it has the appropriate permissions declared in
  * its manifest file. Where permissions apply, they are noted in the
  * the methods through which you access the protected information.
+ *
+ * <p>TelephonyManager is intended for use on devices that implement
+ * {@link android.content.pm.PackageManager#FEATURE_TELEPHONY FEATURE_TELEPHONY}. On devices
+ * that do not implement this feature, the behavior is not reliable.
  */
 @SystemService(Context.TELEPHONY_SERVICE)
 public class TelephonyManager {
@@ -5842,6 +5846,10 @@ public class TelephonyManager {
      * {@link android.telephony.PhoneStateListener#onCellInfoChanged onCellInfoChanged()}
      * for each active subscription.
      *
+     * <p>This method returns valid data for devices with
+     * {@link android.content.pm.PackageManager#FEATURE_TELEPHONY FEATURE_TELEPHONY}. On devices
+     * that do not implement this feature, the behavior is not reliable.
+     *
      * @param executor the executor on which callback will be invoked.
      * @param callback a callback to receive CellInfo.
      */
@@ -5888,6 +5896,10 @@ public class TelephonyManager {
      * {@link android.telephony.PhoneStateListener#onCellInfoChanged onCellInfoChanged()}
      * for each active subscription.
      *
+     * <p>This method returns valid data for devices with
+     * {@link android.content.pm.PackageManager#FEATURE_TELEPHONY FEATURE_TELEPHONY}. On devices
+     * that do not implement this feature, the behavior is not reliable.
+     *
      * @param workSource the requestor to whom the power consumption for this should be attributed.
      * @param executor the executor on which callback will be invoked.
      * @param callback a callback to receive CellInfo.