diff --git a/api/current.txt b/api/current.txt
index c386819..970e3e8 100755
--- a/api/current.txt
+++ b/api/current.txt
@@ -43150,7 +43150,6 @@
     field public static final String EXTRA_STATE_RINGING;
     field public static final String EXTRA_SUBSCRIPTION_ID = "android.telephony.extra.SUBSCRIPTION_ID";
     field public static final String EXTRA_VOICEMAIL_NUMBER = "android.telephony.extra.VOICEMAIL_NUMBER";
-    field public static final int INVALID_CARD_ID = -1; // 0xffffffff
     field public static final String METADATA_HIDE_VOICEMAIL_SETTINGS_MENU = "android.telephony.HIDE_VOICEMAIL_SETTINGS_MENU";
     field public static final int NETWORK_TYPE_1xRTT = 7; // 0x7
     field public static final int NETWORK_TYPE_CDMA = 4; // 0x4
@@ -43186,7 +43185,9 @@
     field public static final int SIM_STATE_PUK_REQUIRED = 3; // 0x3
     field public static final int SIM_STATE_READY = 5; // 0x5
     field public static final int SIM_STATE_UNKNOWN = 0; // 0x0
+    field public static final int UNINITIALIZED_CARD_ID = -2; // 0xfffffffe
     field public static final int UNKNOWN_CARRIER_ID = -1; // 0xffffffff
+    field public static final int UNSUPPORTED_CARD_ID = -1; // 0xffffffff
     field public static final int USSD_ERROR_SERVICE_UNAVAIL = -2; // 0xfffffffe
     field public static final int USSD_RETURN_FAILURE = -1; // 0xffffffff
     field public static final String VVM_TYPE_CVVM = "vvm_type_cvvm";
diff --git a/core/java/android/service/euicc/EuiccService.java b/core/java/android/service/euicc/EuiccService.java
index b84e556..53cc25b 100644
--- a/core/java/android/service/euicc/EuiccService.java
+++ b/core/java/android/service/euicc/EuiccService.java
@@ -76,6 +76,11 @@
  * filter with the appropriate action, the {@link #CATEGORY_EUICC_UI} category, and a non-zero
  * priority.
  *
+ * <p>Old implementations of EuiccService may support passing in slot IDs equal to
+ * {@link android.telephony.SubscriptionManager#INVALID_SIM_SLOT_INDEX}, which allows the LPA to
+ * decide which eUICC to target when there are multiple eUICCs. This behavior is not supported in
+ * Android Q or later.
+ *
  * @hide
  */
 @SystemApi
@@ -520,7 +525,7 @@
                         int resultCode = EuiccService.this.onDownloadSubscription(
                                 slotId, subscription, switchAfterDownload, forceDeactivateSim);
                         result = new DownloadSubscriptionResult(resultCode,
-                            0 /* resolvableErrors */, TelephonyManager.INVALID_CARD_ID);
+                            0 /* resolvableErrors */, TelephonyManager.UNSUPPORTED_CARD_ID);
                     }
                     try {
                         callback.onComplete(result);
diff --git a/telephony/java/android/telephony/TelephonyManager.java b/telephony/java/android/telephony/TelephonyManager.java
index d857fd0..292ff92 100644
--- a/telephony/java/android/telephony/TelephonyManager.java
+++ b/telephony/java/android/telephony/TelephonyManager.java
@@ -227,10 +227,19 @@
     public static final int SRVCC_STATE_HANDOVER_CANCELED  = 3;
 
     /**
-     * An invalid UICC card identifier. See {@link #getCardIdForDefaultEuicc()} and
-     * {@link UiccCardInfo#getCardId()}.
+     * A UICC card identifier used if the device does not support the operation.
+     * For example, {@link #getCardIdForDefaultEuicc()} returns this value if the device has no
+     * eUICC, or the eUICC cannot be read.
      */
-    public static final int INVALID_CARD_ID = -1;
+    public static final int UNSUPPORTED_CARD_ID = -1;
+
+    /**
+     * A UICC card identifier used before the UICC card is loaded. See
+     * {@link #getCardIdForDefaultEuicc()} and {@link UiccCardInfo#getCardId()}.
+     * <p>
+     * Note that once the UICC card is loaded, the card ID may become {@link #UNSUPPORTED_CARD_ID}.
+     */
+    public static final int UNINITIALIZED_CARD_ID = -2;
 
     /** @hide */
     @Retention(RetentionPolicy.SOURCE)
@@ -3099,24 +3108,25 @@
     }
 
     /**
-     * Get the card ID of the default eUICC card. If there is no eUICC, returns
-     * {@link #INVALID_CARD_ID}.
+     * Get the card ID of the default eUICC card. If the eUICCs have not yet been loaded, returns
+     * {@link #UNINITIALIZED_CARD_ID}. If there is no eUICC or the device does not support card IDs
+     * for eUICCs, returns {@link #UNSUPPORTED_CARD_ID}.
      *
      * <p>The card ID is a unique identifier associated with a UICC or eUICC card. Card IDs are
      * unique to a device, and always refer to the same UICC or eUICC card unless the device goes
      * through a factory reset.
      *
-     * @return card ID of the default eUICC card.
+     * @return card ID of the default eUICC card, if loaded.
      */
     public int getCardIdForDefaultEuicc() {
         try {
             ITelephony telephony = getITelephony();
             if (telephony == null) {
-                return INVALID_CARD_ID;
+                return UNINITIALIZED_CARD_ID;
             }
             return telephony.getCardIdForDefaultEuicc(mSubId, mContext.getOpPackageName());
         } catch (RemoteException e) {
-            return INVALID_CARD_ID;
+            return UNINITIALIZED_CARD_ID;
         }
     }
 
diff --git a/telephony/java/android/telephony/euicc/EuiccManager.java b/telephony/java/android/telephony/euicc/EuiccManager.java
index 40c6f70..828e3e9 100644
--- a/telephony/java/android/telephony/euicc/EuiccManager.java
+++ b/telephony/java/android/telephony/euicc/EuiccManager.java
@@ -305,7 +305,7 @@
      */
     @Nullable
     public String getEid() {
-        if (!refreshCardIdIfInvalid()) {
+        if (!refreshCardIdIfUninitialized()) {
             return null;
         }
         try {
@@ -328,7 +328,7 @@
     @SystemApi
     @RequiresPermission(Manifest.permission.WRITE_EMBEDDED_SUBSCRIPTIONS)
     public int getOtaStatus() {
-        if (!refreshCardIdIfInvalid()) {
+        if (!refreshCardIdIfUninitialized()) {
             return EUICC_OTA_STATUS_UNAVAILABLE;
         }
         try {
@@ -363,7 +363,7 @@
     @RequiresPermission(Manifest.permission.WRITE_EMBEDDED_SUBSCRIPTIONS)
     public void downloadSubscription(DownloadableSubscription subscription,
             boolean switchAfterDownload, PendingIntent callbackIntent) {
-        if (!refreshCardIdIfInvalid()) {
+        if (!refreshCardIdIfUninitialized()) {
             sendUnavailableError(callbackIntent);
             return;
         }
@@ -425,7 +425,7 @@
     @SystemApi
     @RequiresPermission(Manifest.permission.WRITE_EMBEDDED_SUBSCRIPTIONS)
     public void continueOperation(Intent resolutionIntent, Bundle resolutionExtras) {
-        if (!refreshCardIdIfInvalid()) {
+        if (!refreshCardIdIfUninitialized()) {
             PendingIntent callbackIntent =
                     resolutionIntent.getParcelableExtra(
                             EuiccManager.EXTRA_EMBEDDED_SUBSCRIPTION_RESOLUTION_CALLBACK_INTENT);
@@ -462,7 +462,7 @@
     @RequiresPermission(Manifest.permission.WRITE_EMBEDDED_SUBSCRIPTIONS)
     public void getDownloadableSubscriptionMetadata(
             DownloadableSubscription subscription, PendingIntent callbackIntent) {
-        if (!refreshCardIdIfInvalid()) {
+        if (!refreshCardIdIfUninitialized()) {
             sendUnavailableError(callbackIntent);
             return;
         }
@@ -492,7 +492,7 @@
     @SystemApi
     @RequiresPermission(Manifest.permission.WRITE_EMBEDDED_SUBSCRIPTIONS)
     public void getDefaultDownloadableSubscriptionList(PendingIntent callbackIntent) {
-        if (!refreshCardIdIfInvalid()) {
+        if (!refreshCardIdIfUninitialized()) {
             sendUnavailableError(callbackIntent);
             return;
         }
@@ -511,7 +511,7 @@
      */
     @Nullable
     public EuiccInfo getEuiccInfo() {
-        if (!refreshCardIdIfInvalid()) {
+        if (!refreshCardIdIfUninitialized()) {
             return null;
         }
         try {
@@ -536,7 +536,7 @@
      */
     @RequiresPermission(Manifest.permission.WRITE_EMBEDDED_SUBSCRIPTIONS)
     public void deleteSubscription(int subscriptionId, PendingIntent callbackIntent) {
-        if (!refreshCardIdIfInvalid()) {
+        if (!refreshCardIdIfUninitialized()) {
             sendUnavailableError(callbackIntent);
             return;
         }
@@ -576,7 +576,7 @@
      */
     @RequiresPermission(Manifest.permission.WRITE_EMBEDDED_SUBSCRIPTIONS)
     public void switchToSubscription(int subscriptionId, PendingIntent callbackIntent) {
-        if (!refreshCardIdIfInvalid()) {
+        if (!refreshCardIdIfUninitialized()) {
             sendUnavailableError(callbackIntent);
             return;
         }
@@ -602,7 +602,7 @@
     @RequiresPermission(Manifest.permission.WRITE_EMBEDDED_SUBSCRIPTIONS)
     public void updateSubscriptionNickname(
             int subscriptionId, String nickname, PendingIntent callbackIntent) {
-        if (!refreshCardIdIfInvalid()) {
+        if (!refreshCardIdIfUninitialized()) {
             sendUnavailableError(callbackIntent);
             return;
         }
@@ -626,7 +626,7 @@
     @SystemApi
     @RequiresPermission(Manifest.permission.WRITE_EMBEDDED_SUBSCRIPTIONS)
     public void eraseSubscriptions(PendingIntent callbackIntent) {
-        if (!refreshCardIdIfInvalid()) {
+        if (!refreshCardIdIfUninitialized()) {
             sendUnavailableError(callbackIntent);
             return;
         }
@@ -656,7 +656,7 @@
      * @hide
      */
     public void retainSubscriptionsForFactoryReset(PendingIntent callbackIntent) {
-        if (!refreshCardIdIfInvalid()) {
+        if (!refreshCardIdIfUninitialized()) {
             sendUnavailableError(callbackIntent);
             return;
         }
@@ -667,16 +667,24 @@
         }
     }
 
-    private boolean refreshCardIdIfInvalid() {
-        if (!isEnabled()) {
-            return false;
-        }
-        // Refresh mCardId if it's invalid.
-        if (mCardId == TelephonyManager.INVALID_CARD_ID) {
+    /**
+     * Refreshes the cardId if its uninitialized, and returns whether we should continue the
+     * operation.
+     * <p>
+     * Note that after a successful refresh, the mCardId may be TelephonyManager.UNSUPPORTED_CARD_ID
+     * on older HALs. For backwards compatability, we continue to the LPA and let it decide which
+     * card to use.
+     */
+    private boolean refreshCardIdIfUninitialized() {
+        // Refresh mCardId if its UNINITIALIZED_CARD_ID
+        if (mCardId == TelephonyManager.UNINITIALIZED_CARD_ID) {
             TelephonyManager tm = (TelephonyManager)
                     mContext.getSystemService(Context.TELEPHONY_SERVICE);
             mCardId = tm.getCardIdForDefaultEuicc();
         }
+        if (mCardId == TelephonyManager.UNINITIALIZED_CARD_ID) {
+            return false;
+        }
         return true;
     }