diff --git a/core/java/android/os/Environment.java b/core/java/android/os/Environment.java
index 8904ee6..a236300 100644
--- a/core/java/android/os/Environment.java
+++ b/core/java/android/os/Environment.java
@@ -382,6 +382,11 @@
     }
 
     /** {@hide} */
+    public static File getDataStagingDirectory(String volumeUuid) {
+        return new File(getDataDirectory(volumeUuid), "staging");
+    }
+
+    /** {@hide} */
     public static File getDataUserCeDirectory(String volumeUuid) {
         return new File(getDataDirectory(volumeUuid), "user");
     }
diff --git a/services/core/java/com/android/server/pm/PackageInstallerService.java b/services/core/java/com/android/server/pm/PackageInstallerService.java
index 66eae5e..7ca39df 100644
--- a/services/core/java/com/android/server/pm/PackageInstallerService.java
+++ b/services/core/java/com/android/server/pm/PackageInstallerService.java
@@ -209,8 +209,7 @@
         synchronized (mSessions) {
             readSessionsLocked();
 
-            reconcileStagesLocked(StorageManager.UUID_PRIVATE_INTERNAL, false /*isInstant*/);
-            reconcileStagesLocked(StorageManager.UUID_PRIVATE_INTERNAL, true /*isInstant*/);
+            reconcileStagesLocked(StorageManager.UUID_PRIVATE_INTERNAL);
 
             final ArraySet<File> unclaimedIcons = newArraySet(
                     mSessionsDir.listFiles());
@@ -230,8 +229,8 @@
     }
 
     @GuardedBy("mSessions")
-    private void reconcileStagesLocked(String volumeUuid, boolean isEphemeral) {
-        final File stagingDir = buildStagingDir(volumeUuid, isEphemeral);
+    private void reconcileStagesLocked(String volumeUuid) {
+        final File stagingDir = getTmpSessionDir(volumeUuid);
         final ArraySet<File> unclaimedStages = newArraySet(
                 stagingDir.listFiles(sStageFilter));
 
@@ -252,7 +251,7 @@
 
     public void onPrivateVolumeMounted(String volumeUuid) {
         synchronized (mSessions) {
-            reconcileStagesLocked(volumeUuid, false /*isInstant*/);
+            reconcileStagesLocked(volumeUuid);
         }
     }
 
@@ -269,9 +268,9 @@
             try {
                 final int sessionId = allocateSessionIdLocked();
                 mLegacySessions.put(sessionId, true);
-                final File stageDir = buildStageDir(volumeUuid, sessionId, isEphemeral);
-                prepareStageDir(stageDir);
-                return stageDir;
+                final File sessionStageDir = buildTmpSessionDir(sessionId, volumeUuid);
+                prepareStageDir(sessionStageDir);
+                return sessionStageDir;
             } catch (IllegalStateException e) {
                 throw new IOException(e);
             }
@@ -526,9 +525,7 @@
         String stageCid = null;
         if (!params.isMultiPackage) {
             if ((params.installFlags & PackageManager.INSTALL_INTERNAL) != 0) {
-                final boolean isInstant =
-                        (params.installFlags & PackageManager.INSTALL_INSTANT_APP) != 0;
-                stageDir = buildStageDir(params.volumeUuid, sessionId, isInstant);
+                stageDir = buildSessionDir(sessionId, params);
             } else {
                 stageCid = buildExternalStageCid(sessionId);
             }
@@ -634,13 +631,21 @@
         throw new IllegalStateException("Failed to allocate session ID");
     }
 
-    private File buildStagingDir(String volumeUuid, boolean isEphemeral) {
+    private File getTmpSessionDir(String volumeUuid) {
         return Environment.getDataAppDirectory(volumeUuid);
     }
 
-    private File buildStageDir(String volumeUuid, int sessionId, boolean isEphemeral) {
-        final File stagingDir = buildStagingDir(volumeUuid, isEphemeral);
-        return new File(stagingDir, "vmdl" + sessionId + ".tmp");
+    private File buildTmpSessionDir(int sessionId, String volumeUuid) {
+        final File sessionStagingDir = getTmpSessionDir(volumeUuid);
+        return new File(sessionStagingDir, "vmdl" + sessionId + ".tmp");
+    }
+
+    private File buildSessionDir(int sessionId, SessionParams params) {
+        if (params.isStaged) {
+            final File sessionStagingDir = Environment.getDataStagingDirectory(params.volumeUuid);
+            return new File(sessionStagingDir, "session_" + sessionId);
+        }
+        return buildTmpSessionDir(sessionId, params.volumeUuid);
     }
 
     static void prepareStageDir(File stageDir) throws IOException {
diff --git a/services/core/java/com/android/server/pm/PackageInstallerSession.java b/services/core/java/com/android/server/pm/PackageInstallerSession.java
index d4ee61b..11b58fb 100644
--- a/services/core/java/com/android/server/pm/PackageInstallerSession.java
+++ b/services/core/java/com/android/server/pm/PackageInstallerSession.java
@@ -977,18 +977,18 @@
 
         // Read transfers from the original owner stay open, but as the session's data
         // cannot be modified anymore, there is no leak of information.
-        if (!params.isMultiPackage) {
+        // For staged sessions, the validation is performed by StagingManager.
+        if (!params.isMultiPackage && !params.isStaged) {
             final PackageInfo pkgInfo = mPm.getPackageInfo(
                     params.appPackageName, PackageManager.GET_SIGNATURES
                             | PackageManager.MATCH_STATIC_SHARED_LIBRARIES /*flags*/, userId);
 
             resolveStageDirLocked();
 
-            // Verify that stage looks sane with respect to existing application.
-            // This currently only ensures packageName, versionCode, and certificate
-            // consistency.
             try {
                 if ((params.installFlags & PackageManager.INSTALL_APEX) != 0) {
+                    // TODO(b/118865310): Remove this when APEX validation is done via
+                    //                    StagingManager.
                     validateApexInstallLocked(pkgInfo);
                 } else {
                     // Verify that stage looks sane with respect to existing application.
@@ -1061,16 +1061,17 @@
     @GuardedBy("mLock")
     private void commitLocked()
             throws PackageManagerException {
+        if (params.isStaged) {
+            mStagingManager.commitSession(this);
+            destroyInternal();
+            dispatchSessionFinished(PackageManager.INSTALL_SUCCEEDED, "Session staged", null);
+            return;
+        }
         final PackageManagerService.ActiveInstallSession committingSession =
                 makeSessionActiveLocked();
         if (committingSession == null) {
             return;
         }
-        if (isStaged()) {
-            mStagingManager.commitSession(this);
-            dispatchSessionFinished(PackageManager.INSTALL_SUCCEEDED, "Session staged", null);
-            return;
-        }
         if (isMultiPackage()) {
             final int[] childSessionIds = getChildSessionIds();
             List<PackageManagerService.ActiveInstallSession> childSessions =
@@ -1973,7 +1974,11 @@
                 bridge.forceClose();
             }
         }
-        if (stageDir != null) {
+        // For staged sessions, we don't delete the directory where the packages have been copied,
+        // since these packages are supposed to be read on reboot. StagingManager is in charge of
+        // deleting these dirs when the staged session has reached a final state.
+        // TODO(b/118865310): Implement packageDir deletion in StagingManager.
+        if (stageDir != null && !params.isStaged) {
             try {
                 mPm.mInstaller.rmPackageDir(stageDir.getAbsolutePath());
             } catch (InstallerException ignored) {
diff --git a/services/core/java/com/android/server/pm/PackageManagerShellCommand.java b/services/core/java/com/android/server/pm/PackageManagerShellCommand.java
index ac9c6ef..2e9d26a 100644
--- a/services/core/java/com/android/server/pm/PackageManagerShellCommand.java
+++ b/services/core/java/com/android/server/pm/PackageManagerShellCommand.java
@@ -2293,6 +2293,9 @@
                     break;
                 case "--apex":
                     sessionParams.installFlags |= PackageManager.INSTALL_APEX;
+                    // TODO(b/118865310): APEX packages should always imply
+                    //                    sessionParams.isStaged(). Enforce this when the staged
+                    //                    install workflow is complete.
                     break;
                 case "--multi-package":
                     sessionParams.setMultiPackage();
@@ -2588,7 +2591,7 @@
         try {
             session = new PackageInstaller.Session(
                     mInterface.getPackageInstaller().openSession(sessionId));
-            if (!session.isMultiPackage()) {
+            if (!session.isMultiPackage() && !session.isStaged()) {
                 // Sanity check that all .dm files match an apk.
                 // (The installer does not support standalone .dm files and will not process them.)
                 try {