diff --git a/nearby/framework/java/android/nearby/NearbyManager.java b/nearby/framework/java/android/nearby/NearbyManager.java
index ea53ab8..fba6ae5 100644
--- a/nearby/framework/java/android/nearby/NearbyManager.java
+++ b/nearby/framework/java/android/nearby/NearbyManager.java
@@ -62,7 +62,7 @@
             ScanStatus.ERROR,
     })
     public @interface ScanStatus {
-        // Default, invalid state.
+        // The undetermined status, some modules may be initializing. Retry is suggested.
         int UNKNOWN = 0;
         // The successful state.
         int SUCCESS = 1;
diff --git a/nearby/service/java/com/android/server/nearby/NearbyService.java b/nearby/service/java/com/android/server/nearby/NearbyService.java
index be3b84e..a1bca19 100644
--- a/nearby/service/java/com/android/server/nearby/NearbyService.java
+++ b/nearby/service/java/com/android/server/nearby/NearbyService.java
@@ -108,10 +108,7 @@
         CallerIdentity identity = CallerIdentity.fromBinder(mContext, packageName, attributionTag);
         DiscoveryPermissions.enforceDiscoveryPermission(mContext, identity);
 
-        if (mProviderManager.registerScanListener(scanRequest, listener, identity)) {
-            return NearbyManager.ScanStatus.SUCCESS;
-        }
-        return NearbyManager.ScanStatus.ERROR;
+        return mProviderManager.registerScanListener(scanRequest, listener, identity);
     }
 
     @Override
diff --git a/nearby/service/java/com/android/server/nearby/provider/ChreCommunication.java b/nearby/service/java/com/android/server/nearby/provider/ChreCommunication.java
index 00e1cb6..9d93843 100644
--- a/nearby/service/java/com/android/server/nearby/provider/ChreCommunication.java
+++ b/nearby/service/java/com/android/server/nearby/provider/ChreCommunication.java
@@ -69,6 +69,8 @@
     private final Executor mExecutor;
 
     private boolean mStarted = false;
+    // null when CHRE availability result has not been returned
+    @Nullable private Boolean mChreSupport = null;
     @Nullable private ContextHubCommsCallback mCallback;
     @Nullable private ContextHubClient mContextHubClient;
 
@@ -78,8 +80,13 @@
         mExecutor = executor;
     }
 
-    public boolean available() {
-        return mContextHubClient != null;
+    /**
+     * @return {@code true} if NanoApp is available and {@code null} when CHRE availability result
+     * has not been returned
+     */
+    @Nullable
+    public Boolean available() {
+        return mChreSupport;
     }
 
     /**
@@ -138,6 +145,7 @@
         if (mContextHubClient != null) {
             mContextHubClient.close();
             mContextHubClient = null;
+            mChreSupport = null;
         }
     }
 
@@ -245,6 +253,7 @@
                                         "Found valid contexthub: %s", mQueriedContextHub.getId()));
                         mContextHubClient = mManager.createClient(mContext, mQueriedContextHub,
                                 mExecutor, ChreCommunication.this);
+                        mChreSupport = true;
                         mCallback.started(true);
                         return;
                     }
@@ -267,6 +276,7 @@
             // there isn't a valid context available on this device.
             if (mContextHubs.isEmpty()) {
                 mCallback.started(false);
+                mChreSupport = false;
             }
         }
     }
diff --git a/nearby/service/java/com/android/server/nearby/provider/ChreDiscoveryProvider.java b/nearby/service/java/com/android/server/nearby/provider/ChreDiscoveryProvider.java
index 105051a..d0d0de0 100644
--- a/nearby/service/java/com/android/server/nearby/provider/ChreDiscoveryProvider.java
+++ b/nearby/service/java/com/android/server/nearby/provider/ChreDiscoveryProvider.java
@@ -24,6 +24,7 @@
 import static service.proto.Blefilter.DataElement.ElementType.DE_CONNECTION_STATUS;
 import static service.proto.Blefilter.DataElement.ElementType.DE_FAST_PAIR_ACCOUNT_KEY;
 
+import android.annotation.Nullable;
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
@@ -59,7 +60,6 @@
     /** @hide */
     @VisibleForTesting public static final int NANOAPP_MESSAGE_TYPE_CONFIG = 5;
 
-    private static final int PRESENCE_UUID = 0xFCF1;
     private static final int FP_ACCOUNT_KEY_LENGTH = 16;
 
     private final ChreCommunication mChreCommunication;
@@ -114,7 +114,12 @@
         onStart();
     }
 
-    public boolean available() {
+    /**
+     * @return {@code true} if CHRE is available and {@code null} when CHRE availability result
+     * has not been returned
+     */
+    @Nullable
+    public Boolean available() {
         return mChreCommunication.available();
     }
 
diff --git a/nearby/service/java/com/android/server/nearby/provider/DiscoveryProviderManager.java b/nearby/service/java/com/android/server/nearby/provider/DiscoveryProviderManager.java
index e4c56e4..b7574c9 100644
--- a/nearby/service/java/com/android/server/nearby/provider/DiscoveryProviderManager.java
+++ b/nearby/service/java/com/android/server/nearby/provider/DiscoveryProviderManager.java
@@ -26,6 +26,7 @@
 import android.nearby.DataElement;
 import android.nearby.IScanListener;
 import android.nearby.NearbyDeviceParcelable;
+import android.nearby.NearbyManager;
 import android.nearby.PresenceScanFilter;
 import android.nearby.ScanFilter;
 import android.nearby.ScanRequest;
@@ -148,7 +149,8 @@
     /**
      * Registers the listener in the manager and starts scan according to the requested scan mode.
      */
-    public boolean registerScanListener(ScanRequest scanRequest, IScanListener listener,
+    @NearbyManager.ScanStatus
+    public int registerScanListener(ScanRequest scanRequest, IScanListener listener,
             CallerIdentity callerIdentity) {
         synchronized (mLock) {
             ScanListenerDeathRecipient deathRecipient = (listener != null)
@@ -166,23 +168,26 @@
                         mScanTypeScanListenerRecordMap.get(listenerBinder).getScanRequest();
                 if (scanRequest.equals(savedScanRequest)) {
                     Log.d(TAG, "Already registered the scanRequest: " + scanRequest);
-                    return true;
+                    return NearbyManager.ScanStatus.SUCCESS;
                 }
             }
             ScanListenerRecord scanListenerRecord =
                     new ScanListenerRecord(scanRequest, listener, callerIdentity, deathRecipient);
             mScanTypeScanListenerRecordMap.put(listenerBinder, scanListenerRecord);
 
-            if (!startProviders(scanRequest)) {
-                return false;
+            Boolean started = startProviders(scanRequest);
+            if (started == null) {
+                return NearbyManager.ScanStatus.UNKNOWN;
             }
-
+            if (!started) {
+                return NearbyManager.ScanStatus.ERROR;
+            }
             NearbyMetrics.logScanStarted(scanListenerRecord.hashCode(), scanRequest);
             if (mScanMode < scanRequest.getScanMode()) {
                 mScanMode = scanRequest.getScanMode();
                 invalidateProviderScanMode();
             }
-            return true;
+            return NearbyManager.ScanStatus.SUCCESS;
         }
     }
 
@@ -237,18 +242,33 @@
         }
     }
 
-    // Returns false when fail to start all the providers. Returns true if any one of the provider
-    // starts successfully.
+    /**
+     * @return {@code null} when all providers are initializing
+     * {@code false} when fail to start all the providers
+     * {@code true} when any one of the provider starts successfully
+     */
     @VisibleForTesting
-    boolean startProviders(ScanRequest scanRequest) {
+    @Nullable
+    Boolean startProviders(ScanRequest scanRequest) {
         if (!scanRequest.isBleEnabled()) {
             Log.w(TAG, "failed to start any provider because client disabled BLE");
             return false;
         }
         List<ScanFilter> scanFilters = getPresenceScanFilters();
+        boolean chreOnly = isChreOnly(scanFilters);
+        Boolean chreAvailable = mChreDiscoveryProvider.available();
+        if (chreAvailable == null) {
+            if (chreOnly) {
+                Log.w(TAG, "client wants CHRE only and Nearby service is still querying CHRE"
+                        + " status");
+                return null;
+            }
+            startBleProvider(scanFilters);
+            return true;
+        }
 
-        if (!mChreDiscoveryProvider.available()) {
-            if (scanRequest.getScanType() == SCAN_TYPE_NEARBY_PRESENCE && isChreOnly(scanFilters)) {
+        if (!chreAvailable) {
+            if (chreOnly) {
                 Log.w(TAG, "failed to start any provider because client wants CHRE only and CHRE"
                         + " is not available");
                 return false;
diff --git a/nearby/tests/unit/src/com/android/server/nearby/provider/DiscoveryProviderManagerTest.java b/nearby/tests/unit/src/com/android/server/nearby/provider/DiscoveryProviderManagerTest.java
index b1737e9..8591b60 100644
--- a/nearby/tests/unit/src/com/android/server/nearby/provider/DiscoveryProviderManagerTest.java
+++ b/nearby/tests/unit/src/com/android/server/nearby/provider/DiscoveryProviderManagerTest.java
@@ -45,7 +45,6 @@
 import org.mockito.MockitoAnnotations;
 
 import java.util.HashMap;
-import java.util.List;
 import java.util.Map;
 
 public class DiscoveryProviderManagerTest {
@@ -76,6 +75,7 @@
         when(mInjector.getAppOpsManager()).thenReturn(mAppOpsManager);
         when(mBleDiscoveryProvider.getController()).thenReturn(mBluetoothController);
         when(mChreDiscoveryProvider.getController()).thenReturn(mChreController);
+
         mScanTypeScanListenerRecordMap = new HashMap<>();
         mDiscoveryProviderManager =
                 new DiscoveryProviderManager(mContext, mInjector, mBleDiscoveryProvider,
@@ -108,10 +108,9 @@
                         mCallerIdentity, mScanListenerDeathRecipient);
         mScanTypeScanListenerRecordMap.put(mIBinder, record);
 
-
-        boolean startProviders = mDiscoveryProviderManager.startProviders(scanRequest);
+        Boolean start = mDiscoveryProviderManager.startProviders(scanRequest);
         verify(mBluetoothController, never()).start();
-        assertThat(startProviders).isTrue();
+        assertThat(start).isTrue();
     }
 
     @Test
@@ -127,9 +126,9 @@
                         mCallerIdentity, mScanListenerDeathRecipient);
         mScanTypeScanListenerRecordMap.put(mIBinder, record);
 
-        boolean startProviders = mDiscoveryProviderManager.startProviders(scanRequest);
+        Boolean start = mDiscoveryProviderManager.startProviders(scanRequest);
         verify(mBluetoothController, never()).start();
-        assertThat(startProviders).isTrue();
+        assertThat(start).isTrue();
     }
 
     @Test
@@ -144,9 +143,9 @@
                         mCallerIdentity, mScanListenerDeathRecipient);
         mScanTypeScanListenerRecordMap.put(mIBinder, record);
 
-        boolean startProviders = mDiscoveryProviderManager.startProviders(scanRequest);
+        Boolean start = mDiscoveryProviderManager.startProviders(scanRequest);
         verify(mBluetoothController, never()).start();
-        assertThat(startProviders).isFalse();
+        assertThat(start).isFalse();
     }
 
     @Test
@@ -161,9 +160,9 @@
                         mCallerIdentity, mScanListenerDeathRecipient);
         mScanTypeScanListenerRecordMap.put(mIBinder, record);
 
-        boolean startProviders = mDiscoveryProviderManager.startProviders(scanRequest);
+        Boolean start = mDiscoveryProviderManager.startProviders(scanRequest);
         verify(mBluetoothController, never()).start();
-        assertThat(startProviders).isTrue();
+        assertThat(start).isTrue();
     }
 
     @Test
@@ -178,14 +177,43 @@
                         mCallerIdentity, mScanListenerDeathRecipient);
         mScanTypeScanListenerRecordMap.put(mIBinder, record);
 
-        boolean startProviders = mDiscoveryProviderManager.startProviders(scanRequest);
+        Boolean start = mDiscoveryProviderManager.startProviders(scanRequest);
         verify(mBluetoothController, atLeastOnce()).start();
-        assertThat(startProviders).isTrue();
+        assertThat(start).isTrue();
     }
 
     @Test
-    public void testStartChreProvider() {
-        mDiscoveryProviderManager.startChreProvider(List.of(getPresenceScanFilter()));
+    public void testStartProviders_chreOnlyChreUndetermined_bleProviderNotStarted() {
+        when(mChreDiscoveryProvider.available()).thenReturn(null);
+
+        ScanRequest scanRequest = new ScanRequest.Builder()
+                .setScanType(SCAN_TYPE_NEARBY_PRESENCE)
+                .addScanFilter(getChreOnlyPresenceScanFilter()).build();
+        DiscoveryProviderManager.ScanListenerRecord record =
+                new DiscoveryProviderManager.ScanListenerRecord(scanRequest, mScanListener,
+                        mCallerIdentity, mScanListenerDeathRecipient);
+        mScanTypeScanListenerRecordMap.put(mIBinder, record);
+
+        Boolean start = mDiscoveryProviderManager.startProviders(scanRequest);
+        verify(mBluetoothController, never()).start();
+        assertThat(start).isNull();
+    }
+
+    @Test
+    public void testStartProviders_notChreOnlyChreUndetermined_bleProviderStarted() {
+        when(mChreDiscoveryProvider.available()).thenReturn(null);
+
+        ScanRequest scanRequest = new ScanRequest.Builder()
+                .setScanType(SCAN_TYPE_NEARBY_PRESENCE)
+                .addScanFilter(getPresenceScanFilter()).build();
+        DiscoveryProviderManager.ScanListenerRecord record =
+                new DiscoveryProviderManager.ScanListenerRecord(scanRequest, mScanListener,
+                        mCallerIdentity, mScanListenerDeathRecipient);
+        mScanTypeScanListenerRecordMap.put(mIBinder, record);
+
+        Boolean start = mDiscoveryProviderManager.startProviders(scanRequest);
+        verify(mBluetoothController, atLeastOnce()).start();
+        assertThat(start).isTrue();
     }
 
     private static PresenceScanFilter getPresenceScanFilter() {