Update release cycle for Windows clients

Windows updates help you to stay productive and protected. They provide your users and IT administrators with the security fixes they need, and protect devices so that unpatched vulnerabilities can't be exploited. Updates for the Windows client OS are typically cumulative. They include all previously released fixes to guard against fragmentation of the operating system. Reliability and vulnerability issues can occur when only a subset of fixes is installed.

This article provides details on the types of updates that Microsoft provides, and how they help make the overall user experience simple and consistent.

Types of update releases

Release type Description Release cycle
Monthly security update release A cumulative update release that includes both security and nonsecurity content Second Tuesday of each month, typically published at 10:00 AM Pacific Time (PST/PDT)
Optional nonsecurity preview release An optional cumulative update release that's typically used for early validation of the monthly security update release Fourth Tuesday of each month, typically published at 10:00 AM Pacific Time (PST/PDT)
Out-of-band (OOB) release Resolves a recently identified issue or vulnerability As needed
Annual feature update An update with new features and enhancements that also changes the Windows version Once a year in the second half of the calendar year
Continuous innovation for Windows 11 Introduces new features and enhancements for Windows 11 Periodically included in an optional nonsecurity preview release then in the monthly security update releases

Monthly security update release

Most people are familiar with the monthly security update release. The monthly security update release is published on the second Tuesday of each month, typically at 10:00 AM Pacific Time (PST/PDT). This release might commonly be referred to as:

  • Patch Tuesday
  • Update Tuesday
  • B week releases (meaning the second week of the month)
  • Quality updates
  • Security updates
  • Latest cumulative update (LCU)

Monthly security update releases are cumulative. The release includes both new and previously released security fixes, along with nonsecurity content introduced in the prior month's Optional nonsecurity preview release. These updates help keep Windows devices secure and compliant by deploying stability fixes and addressing security vulnerabilities. Most organizations consider monthly security update releases as mandatory.

Monthly security update releases are available through the following channels:

Many update management tools, such as Microsoft Configuration Manager and Microsoft Intune, rely on these channels for update deployment.

Optional nonsecurity preview release

Optional nonsecurity preview releases provide IT admins an opportunity for early validation of that content prior to the monthly security update release. Admins can test and validate production-quality releases ahead of the planned monthly security update release for the following month. These updates are optional, cumulative, nonsecurity preview releases. New features might initially be deployed in the prior month's optional nonsecurity preview release, then ship in the following monthly security update release. These releases are only offered to the most recent, supported versions of Windows.

Optional nonsecurity preview releases might commonly be referred to as:

  • C or D week releases (meaning the third or fourth week of the month)
  • Preview updates
  • Preview CU
  • LCU preview


Starting in April 2023, all optional nonsecurity preview releases will be released on the fourth Tuesday of the month. This change in release cadence gives admins a consistent time cycle for testing and validating fixes and features.

To access the optional nonsecurity preview release:

OOB releases

Out-of-band (OOB) releases might be provided to fix a recently identified issue or vulnerability. They're used in atypical cases when an issue is detected and can't wait for the next monthly release, because devices must be updated immediately to address security vulnerabilities or to resolve a quality issue impacting many devices. Out-of-band (OOB) releases are provided outside of the monthly schedule when there's an exceptional need.

Some key considerations about OOB releases include:

  • OOB releases are always cumulative.
    • OOB releases supersede any prior monthly security update and optional nonsecurity preview release.
  • OOB releases generally require IT admins to deploy off-cycle.
  • Some OOB releases are classified as critical.
    • Critical OOB releases are automatically available to WSUS and Windows Update for Business, just like the monthly security update releases.
  • Some OOB releases are classified as noncritical.
    • Noncritical releases only go to the Microsoft Update Catalog for users or organizations to voluntarily obtain the update.

Continuous innovation for Windows 11

Starting with Windows 11, version 22H2, new features and enhancements are introduced periodically to provide continuous innovation for Windows 11. These features and enhancements use the normal update servicing channels you're already familiar with. At first, new features are introduced with an optional nonsecurity preview release and gradually rolled out to unmanaged clients. These new features are released later as part of a monthly security update release.

Some of the new features may be disruptive to organizations. By default, these select features are turned off temporarily for all managed devices until the next annual feature update is installed. In this scenario, a device is considered managed if it uses one of the following to determine which updates to install:

  • Windows Update for Business
    • Devices that have updates managed Microsoft Intune use Windows Update for Business
  • WSUS
    • Devices that have updates managed by Configuration Manager use WSUS

Features that are turned off by default are listed in the KB article for the monthly cumulative update. If you want to enable these features, there's a client policy that allows admins to enable features that are behind temporary enterprise control. For more information about this policy, see Enable features that are behind temporary enterprise feature control.

Annual feature updates

Annual feature updates are released in the second half of the calendar year. These updates are typically cumulative and include all previously released fixes. They also include new features and enhancements. The annual feature update marks the start of the support lifecycle:

  • 24 months of support for Home and Pro editions of Windows
  • 36 months of support for Enterprise and Education editions

For more information, see Windows lifecycle FAQ.

Release information

For more information about specific releases, see: