Microsoft supports .NET on multiple operating systems, per the [Microsoft Modern Lifecycle](https://support.microsoft.com/help/30881/modern-lifecycle-policy).
* Patches are provided (for free) as required for functional or security issues, typically monthly.
* You can [contact Microsoft support to request help](https://support.serviceshub.microsoft.com/supportforbusiness/onboarding) (potentially at a cost).
Knowing key dates for a product lifecycle helps you make informed decisions about when to upgrade or make other changes to your software and computing environment.