[Yandex Cloud documentation](../../index.md) > [Yandex Managed Service for ClickHouse®](../index.md) > [Concepts](index.md) > ClickHouse® versioning policy

# ClickHouse® versioning policy

ClickHouse® employs the frequent release policy. Managed Service for ClickHouse® offers a limited set of ClickHouse® versions: 25.8.24.21 LTS, 26.3.12.3 LTS, 26.4.4.38 and 26.5.2.39. The list of versions is continuously updated. If the ClickHouse® version used in a Managed Service for ClickHouse® cluster becomes deprecated, it gets updated.

Upgrading to current versions allows you to get new features, patches, and security fixes, which improves the overall stability of the cluster.

Each ClickHouse® version supported by Managed Service for ClickHouse® undergoes comprehensive testing. 

Upgrading to a new supported version of ClickHouse® does not affect data integrity and access.


## Versioning policy {#versioning-policy}

Managed Service for ClickHouse® uses two types of ClickHouse® versions:
- **LTS** (Long-Term Support) versions.

  LTS versions are supported for 12 months, with new versions released every 6 months.

  Two LTS versions are supported at the same time: the current one and the previous one. 
  
  When a new LTS version is released in Managed Service for ClickHouse®, the oldest available one becomes obsolete.

- **Interim** versions.

  The three latest ClickHouse® versions, including interim ones, are supported. If one of these versions is an LTS version, only two interim versions are supported.

  When a new interim ClickHouse® version is released in Managed Service for ClickHouse®, the oldest interim one becomes obsolete.

You can manually [update the cluster version](../operations/cluster-version-update.md) to one of the supported versions.

{% note warning %}

* For clusters with an obsolete ClickHouse® version, there is no option to create new hosts or restore from backups.
* Clusters running on an obsolete ClickHouse® version will be automatically updated according to the [update policy](#update-policy).

{% endnote %}


## Update policy {#update-policy}

{% list tabs %}

- LTS versions

  A Managed Service for ClickHouse® cluster running on an obsolete version of ClickHouse® will be updated to the next LTS version.
  
  ![image](../../_assets/mdb/mch-update-policy-lts.svg)
  
  {% note warning %}
  
  Users get notifications about the scheduled update of clusters using an obsolete LTS version **two months** and **one week** prior to the update.

  {% endnote %} 

- Interim versions

  A Managed Service for ClickHouse® cluster running on an obsolete ClickHouse® version will be upgraded to either the nearest LTS version, if available, or the latest interim version.
  
  ![image](../../_assets/mdb/mch-update-policy.svg)
  
  {% note warning %}
     
  * Users get notifications about the scheduled update of clusters using an obsolete interim version **one week** prior to the update.
  * If you upgrade to an LTS version, the appropriate update policy will apply to the cluster.

  {% endnote %}

{% endlist %}

_ClickHouse® is a registered trademark of [ClickHouse, Inc](https://clickhouse.com)._