diff --git a/src/com/android/phone/ImsRcsController.java b/src/com/android/phone/ImsRcsController.java
index bf55764..d4a0f1e 100644
--- a/src/com/android/phone/ImsRcsController.java
+++ b/src/com/android/phone/ImsRcsController.java
@@ -252,7 +252,7 @@
         } catch (ImsException e) {
             Log.e(TAG, "isCapable: sudId=" + subId
                     + ", capability=" + capability + ", " + e.getMessage());
-            return false;
+            throw new ServiceSpecificException(e.getCode(), e.getMessage());
         } finally {
             Binder.restoreCallingIdentity(token);
         }
@@ -278,7 +278,7 @@
         } catch (ImsException e) {
             Log.e(TAG, "isAvailable: sudId=" + subId
                     + ", capability=" + capability + ", " + e.getMessage());
-            return false;
+            throw new ServiceSpecificException(e.getCode(), e.getMessage());
         } finally {
             Binder.restoreCallingIdentity(token);
         }
@@ -786,16 +786,43 @@
         int slotId = phone.getPhoneId();
         if (!skipVerifyingConfig) {
             verifyImsRcsConfiguredOrThrow(slotId);
+            verifyRcsSubIdActiveOrThrow(slotId, subId);
         }
         RcsFeatureController c = mRcsService.getFeatureController(slotId);
         if (c == null) {
+            // If we hit this case, we have verified that TelephonyRcsService has processed any
+            // subId changes for the associated slot and applied configs. In this case, the configs
+            // do not have the RCS feature enabled.
             throw new ServiceSpecificException(ImsException.CODE_ERROR_UNSUPPORTED_OPERATION,
                     "The requested operation is not supported for subId " + subId);
         }
+        if (!skipVerifyingConfig && c.getAssociatedSubId() != subId) {
+            // If we hit this case, the ImsFeature has not finished setting up the RCS feature yet
+            // or the RCS feature has crashed and is being set up again.
+            Log.w(TAG, "getRcsFeatureController: service unavailable on slot " + slotId
+                    + " for subId " + subId);
+            throw new ServiceSpecificException(ImsException.CODE_ERROR_SERVICE_UNAVAILABLE,
+                    "The ImsService is not currently available for subid " + subId
+                            + ", please try again");
+        }
         return c;
     }
 
     /**
+     * Ensure the TelephonyRcsService is tracking the supplied subId for the supplied slotId and has
+     * set up the stack.
+     */
+    private void verifyRcsSubIdActiveOrThrow(int slotId, int subId) {
+        if (mRcsService.verifyActiveSubId(slotId, subId)) return;
+
+        Log.w(TAG, "verifyRcsSubIdActiveOrThrow: verify failed, service not set up yet on "
+                + "slot " + slotId + " for subId " + subId);
+        throw new ServiceSpecificException(ImsException.CODE_ERROR_SERVICE_UNAVAILABLE,
+                "ImsService set up in progress for subId " + subId
+                        + ", please try again");
+    }
+
+    /**
      * Throw an ImsException if the IMS resolver does not have an ImsService configured for RCS
      * for the given slot ID or no ImsResolver instance has been created.
      * @param slotId The slot ID that the IMS service is created for.
diff --git a/src/com/android/services/telephony/rcs/RcsFeatureController.java b/src/com/android/services/telephony/rcs/RcsFeatureController.java
index 0e1cb4b..48c84b1 100644
--- a/src/com/android/services/telephony/rcs/RcsFeatureController.java
+++ b/src/com/android/services/telephony/rcs/RcsFeatureController.java
@@ -19,6 +19,7 @@
 import android.annotation.AnyThread;
 import android.content.Context;
 import android.net.Uri;
+import android.telephony.SubscriptionManager;
 import android.telephony.ims.ImsException;
 import android.telephony.ims.ImsReasonInfo;
 import android.telephony.ims.aidl.IImsCapabilityCallback;
@@ -402,6 +403,17 @@
         callback.accept(mImsRcsRegistrationHelper.getImsRegistrationState());
     }
 
+    /**
+     * @return the subscription ID that is currently associated with this RCS feature.
+     */
+    public int getAssociatedSubId() {
+        RcsFeatureManager manager = getFeatureManager();
+        if (manager != null) {
+            return manager.getSubId();
+        }
+        return SubscriptionManager.INVALID_SUBSCRIPTION_ID;
+    }
+
     private void updateCapabilities() {
         RcsFeatureManager manager = getFeatureManager();
         if (manager != null) {
diff --git a/src/com/android/services/telephony/rcs/TelephonyRcsService.java b/src/com/android/services/telephony/rcs/TelephonyRcsService.java
index dfcea74..13b3a7d 100644
--- a/src/com/android/services/telephony/rcs/TelephonyRcsService.java
+++ b/src/com/android/services/telephony/rcs/TelephonyRcsService.java
@@ -244,6 +244,22 @@
     }
 
     /**
+     * Verifies the subId supplied is the active subId for the slotId specified.
+     * If we have not processed a CARRIER_CONFIG_CHANGED indication for this subscription yet,
+     * either the subscription is not active or we have not finished setting up the feature yet.
+     * @param slotId The slotId we are verifying
+     * @param subId The subId we are verifying
+     * @return true if the subId is the active subId we are tracking for the slotId specified.
+     */
+    public boolean verifyActiveSubId(int slotId, int subId) {
+        synchronized (mLock) {
+            int currId = mSlotToAssociatedSubIds.get(slotId,
+                    SubscriptionManager.INVALID_SUBSCRIPTION_ID);
+            return subId == currId;
+        }
+    }
+
+    /**
      * ACTION_CARRIER_CONFIG_CHANGED was received by this service for a specific slot.
      * @param slotId The slotId associated with the event.
      * @param subId The subId associated with the event. May cause the subId associated with the