---
reviewers:
- sig-api-machinery
- sig-architecture
- sig-cli
- sig-cluster-lifecycle
- sig-node
- sig-release
title: Version Skew Policy
type: docs
description: >
  The maximum version skew supported between various Kubernetes components.
---

<!-- overview -->
This document describes the maximum version skew supported between various Kubernetes components.
Specific cluster deployment tools may place additional restrictions on version skew.

<!-- body -->

## Supported versions

Kubernetes versions are expressed as **x.y.z**, where **x** is the major version,
**y** is the minor version, and **z** is the patch version, following
[Semantic Versioning](https://semver.org/) terminology. For more information, see
[Kubernetes Release Versioning](https://git.k8s.io/sig-release/release-engineering/versioning.md#kubernetes-release-versioning).

The Kubernetes project maintains release branches for the most recent three minor releases
({{< skew latestVersion >}}, {{< skew prevMinorVersion >}}, {{< skew oldestMinorVersion >}}).
Kubernetes 1.19 and newer receive [approximately 1 year of patch support](/releases/patch-releases/#support-period).
Kubernetes 1.18 and older received approximately 9 months of patch support.

Applicable fixes, including security fixes, may be backported to those three release branches,
depending on severity and feasibility. Patch releases are cut from those branches at a
[regular cadence](/releases/patch-releases/#cadence), plus additional urgent releases, when required.

The [Release Managers](/releases/release-managers/) group owns this decision.

For more information, see the Kubernetes [patch releases](/releases/patch-releases/) page.

## Supported version skew

### kube-apiserver

In [highly-available (HA) clusters](/docs/setup/production-environment/tools/kubeadm/high-availability/),
the newest and oldest `kube-apiserver` instances must be within one minor version.

Example:

* newest `kube-apiserver` is at **{{< skew currentVersion >}}**
* other `kube-apiserver` instances are supported at **{{< skew currentVersion >}}** and **{{< skew currentVersionAddMinor -1 >}}**

### kubelet

* `kubelet` must not be newer than `kube-apiserver`.
* `kubelet` may be up to three minor versions older than `kube-apiserver` (`kubelet` < 1.25 may only be up to two minor versions older than `kube-apiserver`).

Example:

* `kube-apiserver` is at **{{< skew currentVersion >}}**
* `kubelet` is supported at **{{< skew currentVersion >}}**, **{{< skew currentVersionAddMinor -1 >}}**,
  **{{< skew currentVersionAddMinor -2 >}}**, and **{{< skew currentVersionAddMinor -3 >}}**

{{< note >}}
If version skew exists between `kube-apiserver` instances in an HA cluster, this narrows the allowed `kubelet` versions.
{{</ note >}}

Example:

* `kube-apiserver` instances are at **{{< skew currentVersion >}}** and **{{< skew currentVersionAddMinor -1 >}}**
* `kubelet` is supported at **{{< skew currentVersionAddMinor -1 >}}**, **{{< skew currentVersionAddMinor -2 >}}**,
  and **{{< skew currentVersionAddMinor -3 >}}** (**{{< skew currentVersion >}}** is not supported because that
  would be newer than the `kube-apiserver` instance at version **{{< skew currentVersionAddMinor -1 >}}**)

### kube-proxy

* `kube-proxy` must not be newer than `kube-apiserver`.
* `kube-proxy` may be up to three minor versions older than `kube-apiserver`
  (`kube-proxy` < 1.25 may only be up to two minor versions older than `kube-apiserver`).
* `kube-proxy` may be up to three minor versions older or newer than the `kubelet` instance
  it runs alongside (`kube-proxy` < 1.25 may only be up to two minor versions older or newer
  than the `kubelet` instance it runs alongside).

Example:

* `kube-apiserver` is at **{{< skew currentVersion >}}**
* `kube-proxy` is supported at **{{< skew currentVersion >}}**, **{{< skew currentVersionAddMinor -1 >}}**,
  **{{< skew currentVersionAddMinor -2 >}}**, and **{{< skew currentVersionAddMinor -3 >}}**

{{< note >}}
If version skew exists between `kube-apiserver` instances in an HA cluster, this narrows the allowed `kube-proxy` versions.