diff --git a/doc/extensions/metadata.md b/doc/extensions/metadata.md
index 8a6c0f624..b8101a71c 100644
--- a/doc/extensions/metadata.md
+++ b/doc/extensions/metadata.md
@@ -50,4 +50,9 @@ Type: `string`
 
 Example: `"azext.maxCliCoreVersion": "2.0.15"`
 
+### azext.isPreview
+Description: Indicate that the extension is in preview.
 
+Type: `boolean`
+
+Example: `"azext.isPreview": true`
diff --git a/src/azure-cli-core/HISTORY.rst b/src/azure-cli-core/HISTORY.rst
index 3e2ee4727..d5d6fa091 100644
--- a/src/azure-cli-core/HISTORY.rst
+++ b/src/azure-cli-core/HISTORY.rst
@@ -6,7 +6,7 @@ Release History
 
 2.0.30
 ++++++
-* Minor fixes
+* Show message for extensions marked as preview on -h.
 
 2.0.29
 ++++++
diff --git a/src/azure-cli-core/azure/cli/core/__init__.py b/src/azure-cli-core/azure/cli/core/__init__.py
index 098feb8f4..e510f4042 100644
--- a/src/azure-cli-core/azure/cli/core/__init__.py
+++ b/src/azure-cli-core/azure/cli/core/__init__.py
@@ -163,7 +163,8 @@ class MainCommandsLoader(CLICommandsLoader):
             if extensions:
                 logger.debug("Found %s extensions: %s", len(extensions), [e.name for e in extensions])
                 allowed_extensions = _handle_extension_suppressions(extensions)
-                for ext_name in [e.name for e in allowed_extensions]:
+                for ext in allowed_extensions:
+                    ext_name = ext.name
                     ext_dir = get_extension_path(ext_name)
                     sys.path.append(ext_dir)
                     try:
@@ -177,7 +178,8 @@ class MainCommandsLoader(CLICommandsLoader):
                         for cmd_name, cmd in extension_command_table.items():
                             cmd.command_source = ExtensionCommandSource(
                                 extension_name=ext_name,
-                                overrides_command=cmd_name in cmd_to_mod_map)
+                                overrides_command=cmd_name in cmd_to_mod_map,
+                                preview=ext.preview)
 
                         self.command_table.update(extension_command_table)
                         elapsed_time = timeit.default_timer() - start_time
diff --git a/src/azure-cli-core/azure/cli/core/_help.py b/src/azure-cli-core/azure/cli/core/_help.py
index f64a8ea7f..a6fad47aa 100644
--- a/src/azure-cli-core/azure/cli/core/_help.py
+++ b/src/azure-cli-core/azure/cli/core/_help.py
@@ -56,6 +56,8 @@ class AzCliHelp(CLIHelp):
             return
         if help_file.command_source and isinstance(help_file.command_source, ExtensionCommandSource):
             logger.warning(help_file.command_source.get_command_warn_msg())
+            if help_file.command_source.preview:
+                logger.warning(help_file.command_source.get_preview_warn_msg())
 
     @classmethod
     def print_detailed_help(cls, cli_name, help_file):
diff --git a/src/azure-cli-core/azure/cli/core/commands/__init__.py b/src/azure-cli-core/azure/cli/core/commands/__init__.py
index cb85cb813..1eeae48ab 100644
--- a/src/azure-cli-core/azure/cli/core/commands/__init__.py
+++ b/src/azure-cli-core/azure/cli/core/commands/__init__.py
@@ -568,11 +568,12 @@ def _load_module_command_loader(loader, args, mod):
 class ExtensionCommandSource(object):
     """ Class for commands contributed by an extension """
 
-    def __init__(self, overrides_command=False, extension_name=None):
+    def __init__(self, overrides_command=False, extension_name=None, preview=False):
         super(ExtensionCommandSource, self).__init__()
         # True if the command overrides a CLI command
         self.overrides_command = overrides_command
         self.extension_name = extension_name
+        self.preview = preview
 
     def get_command_warn_msg(self):
         if self.overrides_command:
@@ -585,6 +586,11 @@ class ExtensionCommandSource(object):
                 return "This command is from the following extension: {}".format(self.extension_name)
             return "This command is from an extension."
 
+    def get_preview_warn_msg(self):
+        if self.preview:
+            return "The extension is in preview"
+        return None
+
 
 def _load_client_exception_class():
     # Since loading msrest is expensive, we avoid it until we have to
diff --git a/src/azure-cli-core/azure/cli/core/extension.py b/src/azure-cli-core/azure/cli/core/extension.py
index 460fba21d..538af3516 100644
--- a/src/azure-cli-core/azure/cli/core/extension.py
+++ b/src/azure-cli-core/azure/cli/core/extension.py
@@ -22,6 +22,7 @@ AZEXT_METADATA_FILENAME = 'azext_metadata.json'
 
 EXT_METADATA_MINCLICOREVERSION = 'azext.minCliCoreVersion'
 EXT_METADATA_MAXCLICOREVERSION = 'azext.maxCliCoreVersion'
+EXT_METADATA_ISPREVIEW = 'azext.isPreview'
 
 logger = get_logger(__name__)
 
@@ -42,6 +43,7 @@ class Extension(object):
         self.ext_type = ext_type
         self._version = None
         self._metadata = None
+        self._preview = None
 
     @property
     def version(self):
@@ -67,6 +69,19 @@ class Extension(object):
             logger.debug("Unable to get extension metadata: %s", traceback.format_exc())
         return self._metadata
 
+    @property
+    def preview(self):
+        """
+        Lazy load preview status.
+        Returns the preview status of the extension.
+        """
+        try:
+            if not isinstance(self._preview, bool):
+                self._preview = bool(self.metadata.get(EXT_METADATA_ISPREVIEW))
+        except Exception:  # pylint: disable=broad-except
+            logger.debug("Unable to get extension preview status: %s", traceback.format_exc())
+        return self._preview
+
     def get_version(self):
         raise NotImplementedError()
 
diff --git a/src/azure-cli-core/azure/cli/core/tests/test_command_registration.py b/src/azure-cli-core/azure/cli/core/tests/test_command_registration.py
index cced5bf71..605299005 100644
--- a/src/azure-cli-core/azure/cli/core/tests/test_command_registration.py
+++ b/src/azure-cli-core/azure/cli/core/tests/test_command_registration.py
@@ -152,9 +152,9 @@ class TestCommandRegistration(unittest.TestCase):
         return ext_name
 
     def _mock_get_extensions():
-        MockExtension = namedtuple('Extension', ['name'])
-        return [MockExtension(name=__name__ + '.ExtCommandsLoader'),
-                MockExtension(name=__name__ + '.Ext2CommandsLoader')]
+        MockExtension = namedtuple('Extension', ['name', 'preview'])
+        return [MockExtension(name=__name__ + '.ExtCommandsLoader', preview=False),
+                MockExtension(name=__name__ + '.Ext2CommandsLoader', preview=False)]
 
     def _mock_load_command_loader(loader, args, name, prefix):
 
diff --git a/src/command_modules/azure-cli-extension/HISTORY.rst b/src/command_modules/azure-cli-extension/HISTORY.rst
index ef5ba6189..b69ea770a 100644
--- a/src/command_modules/azure-cli-extension/HISTORY.rst
+++ b/src/command_modules/azure-cli-extension/HISTORY.rst
@@ -5,7 +5,9 @@ Release History
 
 0.0.11
 ++++++
-* Minor fixes
+* Preview extensions: Show message on `az extension add` if extension is in preview
+* BC: `az extension list-available` - The full extension data is now available with `--show-details`
+* `az extension list-available` - A simplified view of the extensions available is now shown by default
 
 0.0.10
 +++++++
diff --git a/src/command_modules/azure-cli-extension/azure/cli/command_modules/extension/__init__.py b/src/command_modules/azure-cli-extension/azure/cli/command_modules/extension/__init__.py
index 1e6e71651..dd83874fd 100644
--- a/src/command_modules/azure-cli-extension/azure/cli/command_modules/extension/__init__.py
+++ b/src/command_modules/azure-cli-extension/azure/cli/command_modules/extension/__init__.py
@@ -27,7 +27,10 @@ class ExtensionCommandsLoader(AzCommandsLoader):
             return bool(not command_args.get('source') or prompt_y_n('Are you sure you want to install this extension?'))
 
         def transform_extension_list_available(results):
-            return [OrderedDict([('Name', r)]) for r in results]
+            if isinstance(results, dict):
+                # For --show-details, transform the table
+                return [OrderedDict([('Name', r)]) for r in results]
+            return results
 
         def validate_extension_add(namespace):
             if (namespace.extension_name and namespace.source) or (not namespace.extension_name and not namespace.source):
@@ -67,5 +70,8 @@ class ExtensionCommandsLoader(AzCommandsLoader):
             c.argument('source', options_list=['--source', '-s'], help='Filepath or URL to an extension', completer=FilesCompleter())
             c.argument('yes', options_list=['--yes', '-y'], action='store_true', help='Do not prompt for confirmation.')
 
+        with self.argument_context('extension list-available') as c:
+            c.argument('show_details', options_list=['--show-details', '-d'], action='store_true', help='Show the raw data from the extension index.')
+
 
 COMMAND_LOADER_CLS = ExtensionCommandsLoader
diff --git a/src/command_modules/azure-cli-extension/azure/cli/command_modules/extension/custom.py b/src/command_modules/azure-cli-extension/azure/cli/command_modules/extension/custom.py
index ea897338d..9ba515f06 100644
--- a/src/command_modules/azure-cli-extension/azure/cli/command_modules/extension/custom.py
+++ b/src/command_modules/azure-cli-extension/azure/cli/command_modules/extension/custom.py
@@ -11,14 +11,17 @@ import traceback
 import hashlib
 from subprocess import check_output, STDOUT, CalledProcessError
 from six.moves.urllib.parse import urlparse  # pylint: disable=import-error
+from collections import OrderedDict
 
 import requests
 from wheel.install import WHEEL_INFO_RE
+from pkg_resources import parse_version
+
 from knack.log import get_logger
 
 from azure.cli.core.util import CLIError
 from azure.cli.core.extension import (extension_exists, get_extension_path, get_extensions,
-                                      get_extension, ext_compat_with_cli,
+                                      get_extension, ext_compat_with_cli, EXT_METADATA_ISPREVIEW,
                                       WheelExtension, ExtensionNotInstalledException)
 from azure.cli.core.telemetry import set_extension_management_detail
 
@@ -200,6 +203,11 @@ def add_extension(source=None, extension_name=None, index_url=None, yes=None,  #
             raise CLIError("No matching extensions for '{}'. Use --debug for more information.".format(extension_name))
     _add_whl_ext(source, ext_sha256=ext_sha256, pip_extra_index_urls=pip_extra_index_urls, pip_proxy=pip_proxy)
     _augment_telemetry_with_ext_info(extension_name)
+    try:
+        if extension_name and get_extension(extension_name).preview:
+            logger.warning("The installed extension '%s' is in preview.", extension_name)
+    except ExtensionNotInstalledException:
+        pass
 
 
 def remove_extension(extension_name):
@@ -263,8 +271,28 @@ def update_extension(extension_name, index_url=None, pip_extra_index_urls=None,
         raise CLIError(e)
 
 
-def list_available_extensions(index_url=None):
-    return get_index_extensions(index_url=index_url)
+def list_available_extensions(index_url=None, show_details=False):
+    index_data = get_index_extensions(index_url=index_url)
+    if show_details:
+        return index_data
+    installed_extensions = get_extensions()
+    installed_extension_names = [e.name for e in installed_extensions]
+    results = []
+    for name, items in OrderedDict(sorted(index_data.items())).items():
+        latest = sorted(items, key=lambda c: parse_version(c['metadata']['version']), reverse=True)[0]
+        installed = False
+        if name in installed_extension_names:
+            installed = True
+            if parse_version(latest['metadata']['version']) > parse_version(get_extension(name).version):
+                installed = str(True) + ' (upgrade available)'
+        results.append({
+            'name': name,
+            'version': latest['metadata']['version'],
+            'summary': latest['metadata']['summary'],
+            'preview': latest['metadata'].get(EXT_METADATA_ISPREVIEW, False),
+            'installed': installed
+        })
+    return results
 
 
 def get_lsb_release():
@@ -296,14 +324,14 @@ def check_distro_consistency():
     except Exception as err:  # pylint: disable=broad-except
         current_linux_dist_name = None
         stored_linux_dist_name = None
-        logger.debug('Linux distro check: An error occurred while checking \
-linux distribution version source list consistency.')
+        logger.debug('Linux distro check: An error occurred while checking '
+                     'linux distribution version source list consistency.')
         logger.debug(err)
 
     if current_linux_dist_name != stored_linux_dist_name:
-        logger.warning("Linux distro check: Mismatch distribution \
-name in %s file", LIST_FILE_PATH)
-        logger.warning("Linux distro check: If command fails, install the appropriate package \
-for your distribution or change the above file accordingly.")
+        logger.warning("Linux distro check: Mismatch distribution "
+                       "name in %s file", LIST_FILE_PATH)
+        logger.warning("Linux distro check: If command fails, install the appropriate package "
+                       "for your distribution or change the above file accordingly.")
         logger.warning("Linux distro check: %s has '%s', current distro is '%s'",
                        LIST_FILE_PATH, stored_linux_dist_name, current_linux_dist_name)
diff --git a/src/command_modules/azure-cli-extension/azure/cli/command_modules/extension/tests/latest/test_extension_commands.py b/src/command_modules/azure-cli-extension/azure/cli/command_modules/extension/tests/latest/test_extension_commands.py
index 7bf4e3647..2415ca6e9 100644
--- a/src/command_modules/azure-cli-extension/azure/cli/command_modules/extension/tests/latest/test_extension_commands.py
+++ b/src/command_modules/azure-cli-extension/azure/cli/command_modules/extension/tests/latest/test_extension_commands.py
@@ -251,6 +251,29 @@ class TestExtensionCommands(unittest.TestCase):
             list_available_extensions(index_url=index_url)
             c.assert_called_once_with(index_url)
 
+    def test_list_available_extensions_show_details(self):
+        with mock.patch('azure.cli.command_modules.extension.custom.get_index_extensions', autospec=True) as c:
+            list_available_extensions(show_details=True)
+            c.assert_called_once_with(None)
+
+    def test_list_available_extensions_no_show_details(self):
+        sample_index_extensions = {
+            'test_sample_extension1': [{
+                'metadata': {
+                    'name': 'test_sample_extension1',
+                    'summary': 'my summary',
+                    'version': '0.1.0'
+                }}]
+        }
+        with mock.patch('azure.cli.command_modules.extension.custom.get_index_extensions', return_value=sample_index_extensions):
+            res = list_available_extensions()
+            self.assertIsInstance(res, list)
+            self.assertEqual(len(res), len(sample_index_extensions))
+            self.assertEqual(res[0]['name'], 'test_sample_extension1')
+            self.assertEqual(res[0]['summary'], 'my summary')
+            self.assertEqual(res[0]['version'], '0.1.0')
+            self.assertEqual(res[0]['preview'], False)
+
     def test_add_list_show_remove_extension_extra_index_url(self):
         """
         Tests extension addition while specifying --extra-index-url parameter.