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  ## Key facts
  - Environment types have defined intents. Default is for Microsoft 365 personal productivity work, not permanent solutions. Production is for permanent work. Sandbox supports copy and reset and suits testing and ALM builds. Developer environments are personal maker workspaces.
- - Developer environments: up to three per maker, they don't count against tenant capacity, they're turned off after 90 days of no use and removed if the owner doesn't respond, and Dynamics 365 apps aren't available in them.
+ - Developer environments: each maker can create only one managed developer environment (it used to be up to three), unmanaged ones are deprecated, they don't count against tenant capacity, they're turned off after 90 days of no use and removed if the owner doesn't respond, and Dynamics 365 apps aren't available in them.
  - Every environment except trial and developer consumes 1 GB of tenant capacity to provision. Capacity is shared across the tenant.
  - Environment routing redirects makers away from the default environment into a personal developer environment, creating one where needed. It requires managed environments, and environments created by routing are managed by default.
  - Environment groups need managed environments too. An environment belongs to exactly one group, can be moved between groups, and groups can't nest. Rules published to a group lock the corresponding environment settings so an environment admin can't override them.
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  - Makers with a premium or Developer Plan licence can still create developer environments manually, outside any group, with none of your rules applied. Restrict creation in tenant settings or the gap stays open.
  - Group rules lock settings while the environment is in the group. Remove it and it keeps the settings, but an environment admin can now change them.
  - Moving developer environments into region or business-unit groups is a manual action today. If your design depends on it happening automatically, check whether the admin connector supports it yet.
+ - **Deprecated:** Unmanaged developer environments, including the ones the Developer Plan sign-up used to create, are being phased out. Sign-up no longer creates an environment once the phase date passes, so makers need a managed one from their admin (environment routing is the obvious route), and running assets in it needs a premium licence. See [deprecation page](https://learn.microsoft.com/en-us/power-platform/important-changes-coming#deprecation-of-unmanaged-developer-environments-and-the-power-apps-developer-plan).
  - The 90-day developer environment cleanup is a feature until someone's proof of concept evaporates. Anything worth keeping belongs in source control, not in a developer environment.
  - Assets built outside a custom solution land in the default solution and are painful to promote. Setting a preferred solution per environment is the cheap fix and almost nobody does it unprompted.