docs: Add Version Lifecycle page under Getting Started

docs/index.rst

@@ -11,6 +11,7 @@ SageMaker Python SDK V3
    overview
    installation
    quickstart
+   lifecycle
 
 .. toctree::
    :maxdepth: 2

docs/lifecycle.rst

@@ -0,0 +1,119 @@
+Version Lifecycle
+=================
+
+The SageMaker Python SDK follows the `AWS SDKs and Tools maintenance policy
+<https://docs.aws.amazon.com/sdkref/latest/guide/maint-policy.html>`_. This page
+describes the maintenance lifecycle for the major versions of the SDK and the
+timelines associated with each phase.
+
+Version 3 became generally available on 2025-11-19 and is the actively developed
+major version. Version 2 is in maintenance mode: it receives critical bug fixes
+and security updates only, and will not receive new features, API updates, or new
+region support.
+
+.. note::
+   We recommend all users migrate to V3. See the `migration guide
+   <https://github.com/aws/sagemaker-python-sdk/blob/master/migration.md>`_ for
+   detailed guidance on moving from V2 to V3.
+
+Version Support Matrix
+----------------------
+
+The following table shows the available major versions of the SageMaker Python
+SDK and where each is in the maintenance lifecycle.
+
+.. list-table::
+   :header-rows: 1
+   :widths: 20 25 35 20
+
+   * - Major Version
+     - Current Phase
+     - Install
+     - General Availability
+   * - Version 3
+     - General Availability
+     - ``pip install sagemaker``
+     - 2025-11-19
+   * - Version 2
+     - Maintenance mode
+     - ``pip install "sagemaker<3"``
+     - 2020-08-04
+
+Lifecycle Phases
+----------------
+
+Each major version moves through the following phases, as defined by the
+`AWS SDKs and Tools maintenance policy
+<https://docs.aws.amazon.com/sdkref/latest/guide/maint-policy.html>`_:
+
+- **General Availability** -- the SDK is fully supported, with regular releases
+  for new services, API updates, and bug and security fixes.
+- **Maintenance mode** -- AWS limits releases to critical bug fixes and security
+  issues only. No new APIs, features, or region support are added.
+- **End-of-Support** -- the SDK no longer receives updates or releases.
+  Previously published versions remain available on PyPI and the source remains
+  on GitHub.
+
+Version 3
+---------
+
+Version 3 is the current, actively developed major version and is in the
+**General Availability** phase.
+
+.. list-table::
+   :header-rows: 1
+   :widths: 40 30 30
+
+   * - Phase
+     - Start Date
+     - End Date
+   * - General Availability
+     - 2025-11-19
+     - N/A
+
+Version 2
+---------
+
+Version 2 is in **Maintenance mode**. The following table shows its lifecycle
+phases and timelines.
+
+.. list-table::
+   :header-rows: 1
+   :widths: 40 30 30
+
+   * - Phase
+     - Start Date
+     - End Date
+   * - General Availability
+     - 2020-08-04
+     - N/A
+   * - Maintenance mode
+     - 2026-07-06
+     - 2027-07-05
+   * - End-of-Support
+     - 2027-07-06
+     - N/A
+
+Managing Your Version
+---------------------
+
+To upgrade to the latest V3 release:
+
+.. code-block:: bash
+
+   pip install --upgrade sagemaker
+
+To pin to V2 during migration:
+
+.. code-block:: bash
+
+   pip install "sagemaker<3"
+
+Next Steps
+----------
+
+- Read the :doc:`overview` to understand what changed in V3
+- Follow the :doc:`installation` guide to set up V3
+- Review the `migration guide
+  <https://github.com/aws/sagemaker-python-sdk/blob/master/migration.md>`_ to move
+  from V2 to V3