diff --git a/README.md b/README.md
index d51aebaab..d7b5c2596 100644
--- a/README.md
+++ b/README.md
@@ -200,7 +200,7 @@ Then perform the following commands on the root folder:
 | region | The region to host the cluster in (optional if zonal cluster / required if regional) | `string` | `null` | no |
 | regional | Whether is a regional cluster (zonal cluster if set false. WARNING: changing this after cluster creation is destructive!) | `bool` | `true` | no |
 | registry\_project\_ids | Projects holding Google Container Registries. If empty, we use the cluster project. If a service account is created and the `grant_registry_access` variable is set to `true`, the `storage.objectViewer` and `artifactregsitry.reader` roles are assigned on these projects. | `list(string)` | `[]` | no |
-| release\_channel | The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `UNSPECIFIED`. | `string` | `null` | no |
+| release\_channel | The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`. | `string` | `"REGULAR"` | no |
 | remove\_default\_node\_pool | Remove default node pool while setting up the cluster | `bool` | `false` | no |
 | resource\_usage\_export\_dataset\_id | The ID of a BigQuery Dataset for using BigQuery as the destination of resource usage export. | `string` | `""` | no |
 | service\_account | The service account to run nodes as if not overridden in `node_pools`. The create\_service\_account variable default value (true) will cause a cluster-specific service account to be created. This service account should already exists and it will be used by the node pools. If you wish to only override the service account name, you can use service\_account\_name variable. | `string` | `""` | no |
diff --git a/autogen/main/main.tf.tmpl b/autogen/main/main.tf.tmpl
index da8d6d28c..6bb347760 100644
--- a/autogen/main/main.tf.tmpl
+++ b/autogen/main/main.tf.tmpl
@@ -79,12 +79,8 @@ locals {
   cluster_type                = var.regional ? "regional" : "zonal"
 {% if autopilot_cluster != true %}
   // auto upgrade by defaults only for regional cluster as long it has multiple masters versus zonal clusters have only have a single master so upgrades are more dangerous.
-{% if beta_cluster %}
-  // When a release channel is used, node auto-upgrade are enabled and cannot be disabled.
-  default_auto_upgrade = var.regional || var.release_channel != null ? true : false
-{% else %}
-  default_auto_upgrade = var.regional ? true : false
-{% endif %}
+  // When a release channel is used, node auto-upgrade is enabled and cannot be disabled.
+  default_auto_upgrade = var.regional || var.release_channel != "UNSPECIFIED" ? true : false
 {% endif %}
 
   cluster_subnet_cidr       = var.add_cluster_firewall_rules ? data.google_compute_subnetwork.gke_subnetwork[0].ip_cidr_range : null
diff --git a/autogen/main/variables.tf.tmpl b/autogen/main/variables.tf.tmpl
index 3f0959f2c..8bdd17b35 100644
--- a/autogen/main/variables.tf.tmpl
+++ b/autogen/main/variables.tf.tmpl
@@ -464,8 +464,8 @@ variable "identity_namespace" {
 
 variable "release_channel" {
   type        = string
-  description = "The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `UNSPECIFIED`."
-  default     = null
+  description = "The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`."
+  default     = "REGULAR"
 }
 
 variable "gateway_api_channel" {
diff --git a/autogen/safer-cluster/variables.tf.tmpl b/autogen/safer-cluster/variables.tf.tmpl
index 77b185024..d7720b77c 100644
--- a/autogen/safer-cluster/variables.tf.tmpl
+++ b/autogen/safer-cluster/variables.tf.tmpl
@@ -73,7 +73,7 @@ variable "kubernetes_version" {
 
 variable "release_channel" {
   type        = string
-  description = "(Beta) The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`."
+  description = "The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`."
   default     = "REGULAR"
 }
 
diff --git a/docs/upgrading_to_v26.0.md b/docs/upgrading_to_v26.0.md
new file mode 100644
index 000000000..808836104
--- /dev/null
+++ b/docs/upgrading_to_v26.0.md
@@ -0,0 +1,21 @@
+# Upgrading to v26.0
+The v26.0 release of *kubernetes-engine* is a backwards incompatible
+release.
+
+### release_channel now defaults to REGULAR
+
+For all clusters `release_channel` now defaults to `REGULAR`, this was already
+the default for safer_cluster variants.
+
+To opt out of using a release channel, set `release_channel` to `"UNSPECIFIED"`.
+
+```diff
+  module "gke" {
+-   source           = "terraform-google-modules/kubernetes-engine"
+-   version          = "~> 25.0"
++   source           = "terraform-google-modules/kubernetes-engine"
++   version          = "~> 26.0"
+...
++   release_channel = "UNSPECIFIED"
+}
+```
diff --git a/main.tf b/main.tf
index 6d671bfbb..8c4cba521 100644
--- a/main.tf
+++ b/main.tf
@@ -70,7 +70,8 @@ locals {
   zone_count                  = length(var.zones)
   cluster_type                = var.regional ? "regional" : "zonal"
   // auto upgrade by defaults only for regional cluster as long it has multiple masters versus zonal clusters have only have a single master so upgrades are more dangerous.
-  default_auto_upgrade = var.regional ? true : false
+  // When a release channel is used, node auto-upgrade is enabled and cannot be disabled.
+  default_auto_upgrade = var.regional || var.release_channel != "UNSPECIFIED" ? true : false
 
   cluster_subnet_cidr       = var.add_cluster_firewall_rules ? data.google_compute_subnetwork.gke_subnetwork[0].ip_cidr_range : null
   cluster_alias_ranges_cidr = var.add_cluster_firewall_rules ? { for range in toset(data.google_compute_subnetwork.gke_subnetwork[0].secondary_ip_range) : range.range_name => range.ip_cidr_range } : {}
diff --git a/modules/beta-autopilot-private-cluster/README.md b/modules/beta-autopilot-private-cluster/README.md
index 9763ef9ef..bbe938170 100644
--- a/modules/beta-autopilot-private-cluster/README.md
+++ b/modules/beta-autopilot-private-cluster/README.md
@@ -118,7 +118,7 @@ Then perform the following commands on the root folder:
 | region | The region to host the cluster in (optional if zonal cluster / required if regional) | `string` | `null` | no |
 | regional | Whether is a regional cluster (zonal cluster if set false. WARNING: changing this after cluster creation is destructive!) | `bool` | `true` | no |
 | registry\_project\_ids | Projects holding Google Container Registries. If empty, we use the cluster project. If a service account is created and the `grant_registry_access` variable is set to `true`, the `storage.objectViewer` and `artifactregsitry.reader` roles are assigned on these projects. | `list(string)` | `[]` | no |
-| release\_channel | The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `UNSPECIFIED`. | `string` | `null` | no |
+| release\_channel | The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`. | `string` | `"REGULAR"` | no |
 | resource\_usage\_export\_dataset\_id | The ID of a BigQuery Dataset for using BigQuery as the destination of resource usage export. | `string` | `""` | no |
 | service\_account | The service account to run nodes as if not overridden in `node_pools`. The create\_service\_account variable default value (true) will cause a cluster-specific service account to be created. This service account should already exists and it will be used by the node pools. If you wish to only override the service account name, you can use service\_account\_name variable. | `string` | `""` | no |
 | service\_account\_name | The name of the service account that will be created if create\_service\_account is true. If you wish to use an existing service account, use service\_account variable. | `string` | `""` | no |
diff --git a/modules/beta-autopilot-private-cluster/variables.tf b/modules/beta-autopilot-private-cluster/variables.tf
index 8dc2c9a8d..8b0bf17e2 100644
--- a/modules/beta-autopilot-private-cluster/variables.tf
+++ b/modules/beta-autopilot-private-cluster/variables.tf
@@ -301,8 +301,8 @@ variable "identity_namespace" {
 
 variable "release_channel" {
   type        = string
-  description = "The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `UNSPECIFIED`."
-  default     = null
+  description = "The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`."
+  default     = "REGULAR"
 }
 
 variable "gateway_api_channel" {
diff --git a/modules/beta-autopilot-public-cluster/README.md b/modules/beta-autopilot-public-cluster/README.md
index 05876ae44..91a48d9ce 100644
--- a/modules/beta-autopilot-public-cluster/README.md
+++ b/modules/beta-autopilot-public-cluster/README.md
@@ -107,7 +107,7 @@ Then perform the following commands on the root folder:
 | region | The region to host the cluster in (optional if zonal cluster / required if regional) | `string` | `null` | no |
 | regional | Whether is a regional cluster (zonal cluster if set false. WARNING: changing this after cluster creation is destructive!) | `bool` | `true` | no |
 | registry\_project\_ids | Projects holding Google Container Registries. If empty, we use the cluster project. If a service account is created and the `grant_registry_access` variable is set to `true`, the `storage.objectViewer` and `artifactregsitry.reader` roles are assigned on these projects. | `list(string)` | `[]` | no |
-| release\_channel | The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `UNSPECIFIED`. | `string` | `null` | no |
+| release\_channel | The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`. | `string` | `"REGULAR"` | no |
 | resource\_usage\_export\_dataset\_id | The ID of a BigQuery Dataset for using BigQuery as the destination of resource usage export. | `string` | `""` | no |
 | service\_account | The service account to run nodes as if not overridden in `node_pools`. The create\_service\_account variable default value (true) will cause a cluster-specific service account to be created. This service account should already exists and it will be used by the node pools. If you wish to only override the service account name, you can use service\_account\_name variable. | `string` | `""` | no |
 | service\_account\_name | The name of the service account that will be created if create\_service\_account is true. If you wish to use an existing service account, use service\_account variable. | `string` | `""` | no |
diff --git a/modules/beta-autopilot-public-cluster/variables.tf b/modules/beta-autopilot-public-cluster/variables.tf
index 95d24d69f..947bf6df8 100644
--- a/modules/beta-autopilot-public-cluster/variables.tf
+++ b/modules/beta-autopilot-public-cluster/variables.tf
@@ -271,8 +271,8 @@ variable "identity_namespace" {
 
 variable "release_channel" {
   type        = string
-  description = "The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `UNSPECIFIED`."
-  default     = null
+  description = "The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`."
+  default     = "REGULAR"
 }
 
 variable "gateway_api_channel" {
diff --git a/modules/beta-private-cluster-update-variant/README.md b/modules/beta-private-cluster-update-variant/README.md
index eb3e39aaf..1578646b4 100644
--- a/modules/beta-private-cluster-update-variant/README.md
+++ b/modules/beta-private-cluster-update-variant/README.md
@@ -250,7 +250,7 @@ Then perform the following commands on the root folder:
 | region | The region to host the cluster in (optional if zonal cluster / required if regional) | `string` | `null` | no |
 | regional | Whether is a regional cluster (zonal cluster if set false. WARNING: changing this after cluster creation is destructive!) | `bool` | `true` | no |
 | registry\_project\_ids | Projects holding Google Container Registries. If empty, we use the cluster project. If a service account is created and the `grant_registry_access` variable is set to `true`, the `storage.objectViewer` and `artifactregsitry.reader` roles are assigned on these projects. | `list(string)` | `[]` | no |
-| release\_channel | The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `UNSPECIFIED`. | `string` | `null` | no |
+| release\_channel | The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`. | `string` | `"REGULAR"` | no |
 | remove\_default\_node\_pool | Remove default node pool while setting up the cluster | `bool` | `false` | no |
 | resource\_usage\_export\_dataset\_id | The ID of a BigQuery Dataset for using BigQuery as the destination of resource usage export. | `string` | `""` | no |
 | sandbox\_enabled | (Beta) Enable GKE Sandbox (Do not forget to set `image_type` = `COS_CONTAINERD` to use it). | `bool` | `false` | no |
diff --git a/modules/beta-private-cluster-update-variant/main.tf b/modules/beta-private-cluster-update-variant/main.tf
index dbbf64e97..69a88465d 100644
--- a/modules/beta-private-cluster-update-variant/main.tf
+++ b/modules/beta-private-cluster-update-variant/main.tf
@@ -70,8 +70,8 @@ locals {
   zone_count                  = length(var.zones)
   cluster_type                = var.regional ? "regional" : "zonal"
   // auto upgrade by defaults only for regional cluster as long it has multiple masters versus zonal clusters have only have a single master so upgrades are more dangerous.
-  // When a release channel is used, node auto-upgrade are enabled and cannot be disabled.
-  default_auto_upgrade = var.regional || var.release_channel != null ? true : false
+  // When a release channel is used, node auto-upgrade is enabled and cannot be disabled.
+  default_auto_upgrade = var.regional || var.release_channel != "UNSPECIFIED" ? true : false
 
   cluster_subnet_cidr       = var.add_cluster_firewall_rules ? data.google_compute_subnetwork.gke_subnetwork[0].ip_cidr_range : null
   cluster_alias_ranges_cidr = var.add_cluster_firewall_rules ? { for range in toset(data.google_compute_subnetwork.gke_subnetwork[0].secondary_ip_range) : range.range_name => range.ip_cidr_range } : {}
diff --git a/modules/beta-private-cluster-update-variant/variables.tf b/modules/beta-private-cluster-update-variant/variables.tf
index 2f5a967c4..7f285bcc0 100644
--- a/modules/beta-private-cluster-update-variant/variables.tf
+++ b/modules/beta-private-cluster-update-variant/variables.tf
@@ -437,8 +437,8 @@ variable "identity_namespace" {
 
 variable "release_channel" {
   type        = string
-  description = "The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `UNSPECIFIED`."
-  default     = null
+  description = "The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`."
+  default     = "REGULAR"
 }
 
 variable "gateway_api_channel" {
diff --git a/modules/beta-private-cluster/README.md b/modules/beta-private-cluster/README.md
index 75b04ff7b..3e994e406 100644
--- a/modules/beta-private-cluster/README.md
+++ b/modules/beta-private-cluster/README.md
@@ -228,7 +228,7 @@ Then perform the following commands on the root folder:
 | region | The region to host the cluster in (optional if zonal cluster / required if regional) | `string` | `null` | no |
 | regional | Whether is a regional cluster (zonal cluster if set false. WARNING: changing this after cluster creation is destructive!) | `bool` | `true` | no |
 | registry\_project\_ids | Projects holding Google Container Registries. If empty, we use the cluster project. If a service account is created and the `grant_registry_access` variable is set to `true`, the `storage.objectViewer` and `artifactregsitry.reader` roles are assigned on these projects. | `list(string)` | `[]` | no |
-| release\_channel | The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `UNSPECIFIED`. | `string` | `null` | no |
+| release\_channel | The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`. | `string` | `"REGULAR"` | no |
 | remove\_default\_node\_pool | Remove default node pool while setting up the cluster | `bool` | `false` | no |
 | resource\_usage\_export\_dataset\_id | The ID of a BigQuery Dataset for using BigQuery as the destination of resource usage export. | `string` | `""` | no |
 | sandbox\_enabled | (Beta) Enable GKE Sandbox (Do not forget to set `image_type` = `COS_CONTAINERD` to use it). | `bool` | `false` | no |
diff --git a/modules/beta-private-cluster/main.tf b/modules/beta-private-cluster/main.tf
index dbbf64e97..69a88465d 100644
--- a/modules/beta-private-cluster/main.tf
+++ b/modules/beta-private-cluster/main.tf
@@ -70,8 +70,8 @@ locals {
   zone_count                  = length(var.zones)
   cluster_type                = var.regional ? "regional" : "zonal"
   // auto upgrade by defaults only for regional cluster as long it has multiple masters versus zonal clusters have only have a single master so upgrades are more dangerous.
-  // When a release channel is used, node auto-upgrade are enabled and cannot be disabled.
-  default_auto_upgrade = var.regional || var.release_channel != null ? true : false
+  // When a release channel is used, node auto-upgrade is enabled and cannot be disabled.
+  default_auto_upgrade = var.regional || var.release_channel != "UNSPECIFIED" ? true : false
 
   cluster_subnet_cidr       = var.add_cluster_firewall_rules ? data.google_compute_subnetwork.gke_subnetwork[0].ip_cidr_range : null
   cluster_alias_ranges_cidr = var.add_cluster_firewall_rules ? { for range in toset(data.google_compute_subnetwork.gke_subnetwork[0].secondary_ip_range) : range.range_name => range.ip_cidr_range } : {}
diff --git a/modules/beta-private-cluster/variables.tf b/modules/beta-private-cluster/variables.tf
index 2f5a967c4..7f285bcc0 100644
--- a/modules/beta-private-cluster/variables.tf
+++ b/modules/beta-private-cluster/variables.tf
@@ -437,8 +437,8 @@ variable "identity_namespace" {
 
 variable "release_channel" {
   type        = string
-  description = "The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `UNSPECIFIED`."
-  default     = null
+  description = "The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`."
+  default     = "REGULAR"
 }
 
 variable "gateway_api_channel" {
diff --git a/modules/beta-public-cluster-update-variant/README.md b/modules/beta-public-cluster-update-variant/README.md
index 4822ebf46..3535d6526 100644
--- a/modules/beta-public-cluster-update-variant/README.md
+++ b/modules/beta-public-cluster-update-variant/README.md
@@ -239,7 +239,7 @@ Then perform the following commands on the root folder:
 | region | The region to host the cluster in (optional if zonal cluster / required if regional) | `string` | `null` | no |
 | regional | Whether is a regional cluster (zonal cluster if set false. WARNING: changing this after cluster creation is destructive!) | `bool` | `true` | no |
 | registry\_project\_ids | Projects holding Google Container Registries. If empty, we use the cluster project. If a service account is created and the `grant_registry_access` variable is set to `true`, the `storage.objectViewer` and `artifactregsitry.reader` roles are assigned on these projects. | `list(string)` | `[]` | no |
-| release\_channel | The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `UNSPECIFIED`. | `string` | `null` | no |
+| release\_channel | The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`. | `string` | `"REGULAR"` | no |
 | remove\_default\_node\_pool | Remove default node pool while setting up the cluster | `bool` | `false` | no |
 | resource\_usage\_export\_dataset\_id | The ID of a BigQuery Dataset for using BigQuery as the destination of resource usage export. | `string` | `""` | no |
 | sandbox\_enabled | (Beta) Enable GKE Sandbox (Do not forget to set `image_type` = `COS_CONTAINERD` to use it). | `bool` | `false` | no |
diff --git a/modules/beta-public-cluster-update-variant/main.tf b/modules/beta-public-cluster-update-variant/main.tf
index 59ae5281d..30220c7cc 100644
--- a/modules/beta-public-cluster-update-variant/main.tf
+++ b/modules/beta-public-cluster-update-variant/main.tf
@@ -70,8 +70,8 @@ locals {
   zone_count                  = length(var.zones)
   cluster_type                = var.regional ? "regional" : "zonal"
   // auto upgrade by defaults only for regional cluster as long it has multiple masters versus zonal clusters have only have a single master so upgrades are more dangerous.
-  // When a release channel is used, node auto-upgrade are enabled and cannot be disabled.
-  default_auto_upgrade = var.regional || var.release_channel != null ? true : false
+  // When a release channel is used, node auto-upgrade is enabled and cannot be disabled.
+  default_auto_upgrade = var.regional || var.release_channel != "UNSPECIFIED" ? true : false
 
   cluster_subnet_cidr       = var.add_cluster_firewall_rules ? data.google_compute_subnetwork.gke_subnetwork[0].ip_cidr_range : null
   cluster_alias_ranges_cidr = var.add_cluster_firewall_rules ? { for range in toset(data.google_compute_subnetwork.gke_subnetwork[0].secondary_ip_range) : range.range_name => range.ip_cidr_range } : {}
diff --git a/modules/beta-public-cluster-update-variant/variables.tf b/modules/beta-public-cluster-update-variant/variables.tf
index d096780a3..3c7169e00 100644
--- a/modules/beta-public-cluster-update-variant/variables.tf
+++ b/modules/beta-public-cluster-update-variant/variables.tf
@@ -407,8 +407,8 @@ variable "identity_namespace" {
 
 variable "release_channel" {
   type        = string
-  description = "The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `UNSPECIFIED`."
-  default     = null
+  description = "The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`."
+  default     = "REGULAR"
 }
 
 variable "gateway_api_channel" {
diff --git a/modules/beta-public-cluster/README.md b/modules/beta-public-cluster/README.md
index a6d1d33d3..608300463 100644
--- a/modules/beta-public-cluster/README.md
+++ b/modules/beta-public-cluster/README.md
@@ -217,7 +217,7 @@ Then perform the following commands on the root folder:
 | region | The region to host the cluster in (optional if zonal cluster / required if regional) | `string` | `null` | no |
 | regional | Whether is a regional cluster (zonal cluster if set false. WARNING: changing this after cluster creation is destructive!) | `bool` | `true` | no |
 | registry\_project\_ids | Projects holding Google Container Registries. If empty, we use the cluster project. If a service account is created and the `grant_registry_access` variable is set to `true`, the `storage.objectViewer` and `artifactregsitry.reader` roles are assigned on these projects. | `list(string)` | `[]` | no |
-| release\_channel | The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `UNSPECIFIED`. | `string` | `null` | no |
+| release\_channel | The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`. | `string` | `"REGULAR"` | no |
 | remove\_default\_node\_pool | Remove default node pool while setting up the cluster | `bool` | `false` | no |
 | resource\_usage\_export\_dataset\_id | The ID of a BigQuery Dataset for using BigQuery as the destination of resource usage export. | `string` | `""` | no |
 | sandbox\_enabled | (Beta) Enable GKE Sandbox (Do not forget to set `image_type` = `COS_CONTAINERD` to use it). | `bool` | `false` | no |
diff --git a/modules/beta-public-cluster/main.tf b/modules/beta-public-cluster/main.tf
index 59ae5281d..30220c7cc 100644
--- a/modules/beta-public-cluster/main.tf
+++ b/modules/beta-public-cluster/main.tf
@@ -70,8 +70,8 @@ locals {
   zone_count                  = length(var.zones)
   cluster_type                = var.regional ? "regional" : "zonal"
   // auto upgrade by defaults only for regional cluster as long it has multiple masters versus zonal clusters have only have a single master so upgrades are more dangerous.
-  // When a release channel is used, node auto-upgrade are enabled and cannot be disabled.
-  default_auto_upgrade = var.regional || var.release_channel != null ? true : false
+  // When a release channel is used, node auto-upgrade is enabled and cannot be disabled.
+  default_auto_upgrade = var.regional || var.release_channel != "UNSPECIFIED" ? true : false
 
   cluster_subnet_cidr       = var.add_cluster_firewall_rules ? data.google_compute_subnetwork.gke_subnetwork[0].ip_cidr_range : null
   cluster_alias_ranges_cidr = var.add_cluster_firewall_rules ? { for range in toset(data.google_compute_subnetwork.gke_subnetwork[0].secondary_ip_range) : range.range_name => range.ip_cidr_range } : {}
diff --git a/modules/beta-public-cluster/variables.tf b/modules/beta-public-cluster/variables.tf
index d096780a3..3c7169e00 100644
--- a/modules/beta-public-cluster/variables.tf
+++ b/modules/beta-public-cluster/variables.tf
@@ -407,8 +407,8 @@ variable "identity_namespace" {
 
 variable "release_channel" {
   type        = string
-  description = "The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `UNSPECIFIED`."
-  default     = null
+  description = "The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`."
+  default     = "REGULAR"
 }
 
 variable "gateway_api_channel" {
diff --git a/modules/private-cluster-update-variant/README.md b/modules/private-cluster-update-variant/README.md
index 9e614719b..4e645df6b 100644
--- a/modules/private-cluster-update-variant/README.md
+++ b/modules/private-cluster-update-variant/README.md
@@ -233,7 +233,7 @@ Then perform the following commands on the root folder:
 | region | The region to host the cluster in (optional if zonal cluster / required if regional) | `string` | `null` | no |
 | regional | Whether is a regional cluster (zonal cluster if set false. WARNING: changing this after cluster creation is destructive!) | `bool` | `true` | no |
 | registry\_project\_ids | Projects holding Google Container Registries. If empty, we use the cluster project. If a service account is created and the `grant_registry_access` variable is set to `true`, the `storage.objectViewer` and `artifactregsitry.reader` roles are assigned on these projects. | `list(string)` | `[]` | no |
-| release\_channel | The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `UNSPECIFIED`. | `string` | `null` | no |
+| release\_channel | The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`. | `string` | `"REGULAR"` | no |
 | remove\_default\_node\_pool | Remove default node pool while setting up the cluster | `bool` | `false` | no |
 | resource\_usage\_export\_dataset\_id | The ID of a BigQuery Dataset for using BigQuery as the destination of resource usage export. | `string` | `""` | no |
 | service\_account | The service account to run nodes as if not overridden in `node_pools`. The create\_service\_account variable default value (true) will cause a cluster-specific service account to be created. This service account should already exists and it will be used by the node pools. If you wish to only override the service account name, you can use service\_account\_name variable. | `string` | `""` | no |
diff --git a/modules/private-cluster-update-variant/main.tf b/modules/private-cluster-update-variant/main.tf
index 5ae0f32e4..fe1520fca 100644
--- a/modules/private-cluster-update-variant/main.tf
+++ b/modules/private-cluster-update-variant/main.tf
@@ -70,7 +70,8 @@ locals {
   zone_count                  = length(var.zones)
   cluster_type                = var.regional ? "regional" : "zonal"
   // auto upgrade by defaults only for regional cluster as long it has multiple masters versus zonal clusters have only have a single master so upgrades are more dangerous.
-  default_auto_upgrade = var.regional ? true : false
+  // When a release channel is used, node auto-upgrade is enabled and cannot be disabled.
+  default_auto_upgrade = var.regional || var.release_channel != "UNSPECIFIED" ? true : false
 
   cluster_subnet_cidr       = var.add_cluster_firewall_rules ? data.google_compute_subnetwork.gke_subnetwork[0].ip_cidr_range : null
   cluster_alias_ranges_cidr = var.add_cluster_firewall_rules ? { for range in toset(data.google_compute_subnetwork.gke_subnetwork[0].secondary_ip_range) : range.range_name => range.ip_cidr_range } : {}
diff --git a/modules/private-cluster-update-variant/variables.tf b/modules/private-cluster-update-variant/variables.tf
index b48d88f20..c6f8db81e 100644
--- a/modules/private-cluster-update-variant/variables.tf
+++ b/modules/private-cluster-update-variant/variables.tf
@@ -429,8 +429,8 @@ variable "identity_namespace" {
 
 variable "release_channel" {
   type        = string
-  description = "The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `UNSPECIFIED`."
-  default     = null
+  description = "The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`."
+  default     = "REGULAR"
 }
 
 variable "gateway_api_channel" {
diff --git a/modules/private-cluster/README.md b/modules/private-cluster/README.md
index 5c27de7a0..23058af6e 100644
--- a/modules/private-cluster/README.md
+++ b/modules/private-cluster/README.md
@@ -211,7 +211,7 @@ Then perform the following commands on the root folder:
 | region | The region to host the cluster in (optional if zonal cluster / required if regional) | `string` | `null` | no |
 | regional | Whether is a regional cluster (zonal cluster if set false. WARNING: changing this after cluster creation is destructive!) | `bool` | `true` | no |
 | registry\_project\_ids | Projects holding Google Container Registries. If empty, we use the cluster project. If a service account is created and the `grant_registry_access` variable is set to `true`, the `storage.objectViewer` and `artifactregsitry.reader` roles are assigned on these projects. | `list(string)` | `[]` | no |
-| release\_channel | The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `UNSPECIFIED`. | `string` | `null` | no |
+| release\_channel | The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`. | `string` | `"REGULAR"` | no |
 | remove\_default\_node\_pool | Remove default node pool while setting up the cluster | `bool` | `false` | no |
 | resource\_usage\_export\_dataset\_id | The ID of a BigQuery Dataset for using BigQuery as the destination of resource usage export. | `string` | `""` | no |
 | service\_account | The service account to run nodes as if not overridden in `node_pools`. The create\_service\_account variable default value (true) will cause a cluster-specific service account to be created. This service account should already exists and it will be used by the node pools. If you wish to only override the service account name, you can use service\_account\_name variable. | `string` | `""` | no |
diff --git a/modules/private-cluster/main.tf b/modules/private-cluster/main.tf
index 5ae0f32e4..fe1520fca 100644
--- a/modules/private-cluster/main.tf
+++ b/modules/private-cluster/main.tf
@@ -70,7 +70,8 @@ locals {
   zone_count                  = length(var.zones)
   cluster_type                = var.regional ? "regional" : "zonal"
   // auto upgrade by defaults only for regional cluster as long it has multiple masters versus zonal clusters have only have a single master so upgrades are more dangerous.
-  default_auto_upgrade = var.regional ? true : false
+  // When a release channel is used, node auto-upgrade is enabled and cannot be disabled.
+  default_auto_upgrade = var.regional || var.release_channel != "UNSPECIFIED" ? true : false
 
   cluster_subnet_cidr       = var.add_cluster_firewall_rules ? data.google_compute_subnetwork.gke_subnetwork[0].ip_cidr_range : null
   cluster_alias_ranges_cidr = var.add_cluster_firewall_rules ? { for range in toset(data.google_compute_subnetwork.gke_subnetwork[0].secondary_ip_range) : range.range_name => range.ip_cidr_range } : {}
diff --git a/modules/private-cluster/variables.tf b/modules/private-cluster/variables.tf
index b48d88f20..c6f8db81e 100644
--- a/modules/private-cluster/variables.tf
+++ b/modules/private-cluster/variables.tf
@@ -429,8 +429,8 @@ variable "identity_namespace" {
 
 variable "release_channel" {
   type        = string
-  description = "The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `UNSPECIFIED`."
-  default     = null
+  description = "The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`."
+  default     = "REGULAR"
 }
 
 variable "gateway_api_channel" {
diff --git a/modules/safer-cluster-update-variant/README.md b/modules/safer-cluster-update-variant/README.md
index e60325306..d3676146e 100644
--- a/modules/safer-cluster-update-variant/README.md
+++ b/modules/safer-cluster-update-variant/README.md
@@ -262,7 +262,7 @@ For simplicity, we suggest using `roles/container.admin` and
 | region | The region to host the cluster in | `string` | n/a | yes |
 | regional | Whether is a regional cluster (zonal cluster if set false. WARNING: changing this after cluster creation is destructive!) | `bool` | `true` | no |
 | registry\_project\_ids | Projects holding Google Container Registries. If empty, we use the cluster project. If a service account is created and the `grant_registry_access` variable is set to `true`, the `storage.objectViewer` role is assigned on these projects. | `list(string)` | `[]` | no |
-| release\_channel | (Beta) The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`. | `string` | `"REGULAR"` | no |
+| release\_channel | The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`. | `string` | `"REGULAR"` | no |
 | resource\_usage\_export\_dataset\_id | The dataset id for which network egress metering for this cluster will be enabled. If enabled, a daemonset will be created in the cluster to meter network egress traffic. | `string` | `""` | no |
 | sandbox\_enabled | (Beta) Enable GKE Sandbox (Do not forget to set `image_type` = `COS_CONTAINERD` to use it). | `bool` | `false` | no |
 | stub\_domains | Map of stub domains and their resolvers to forward DNS queries for a certain domain to an external DNS server | `map(list(string))` | `{}` | no |
diff --git a/modules/safer-cluster-update-variant/variables.tf b/modules/safer-cluster-update-variant/variables.tf
index 67d343060..bf39b9535 100644
--- a/modules/safer-cluster-update-variant/variables.tf
+++ b/modules/safer-cluster-update-variant/variables.tf
@@ -73,7 +73,7 @@ variable "kubernetes_version" {
 
 variable "release_channel" {
   type        = string
-  description = "(Beta) The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`."
+  description = "The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`."
   default     = "REGULAR"
 }
 
diff --git a/modules/safer-cluster/README.md b/modules/safer-cluster/README.md
index e60325306..d3676146e 100644
--- a/modules/safer-cluster/README.md
+++ b/modules/safer-cluster/README.md
@@ -262,7 +262,7 @@ For simplicity, we suggest using `roles/container.admin` and
 | region | The region to host the cluster in | `string` | n/a | yes |
 | regional | Whether is a regional cluster (zonal cluster if set false. WARNING: changing this after cluster creation is destructive!) | `bool` | `true` | no |
 | registry\_project\_ids | Projects holding Google Container Registries. If empty, we use the cluster project. If a service account is created and the `grant_registry_access` variable is set to `true`, the `storage.objectViewer` role is assigned on these projects. | `list(string)` | `[]` | no |
-| release\_channel | (Beta) The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`. | `string` | `"REGULAR"` | no |
+| release\_channel | The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`. | `string` | `"REGULAR"` | no |
 | resource\_usage\_export\_dataset\_id | The dataset id for which network egress metering for this cluster will be enabled. If enabled, a daemonset will be created in the cluster to meter network egress traffic. | `string` | `""` | no |
 | sandbox\_enabled | (Beta) Enable GKE Sandbox (Do not forget to set `image_type` = `COS_CONTAINERD` to use it). | `bool` | `false` | no |
 | stub\_domains | Map of stub domains and their resolvers to forward DNS queries for a certain domain to an external DNS server | `map(list(string))` | `{}` | no |
diff --git a/modules/safer-cluster/variables.tf b/modules/safer-cluster/variables.tf
index 67d343060..bf39b9535 100644
--- a/modules/safer-cluster/variables.tf
+++ b/modules/safer-cluster/variables.tf
@@ -73,7 +73,7 @@ variable "kubernetes_version" {
 
 variable "release_channel" {
   type        = string
-  description = "(Beta) The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`."
+  description = "The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`."
   default     = "REGULAR"
 }
 
diff --git a/test/setup/main.tf b/test/setup/main.tf
index 166609d7c..81200b572 100644
--- a/test/setup/main.tf
+++ b/test/setup/main.tf
@@ -30,7 +30,6 @@ locals {
     "anthosconfigmanagement.googleapis.com",
     "logging.googleapis.com",
     "meshca.googleapis.com",
-    "meshtelemetry.googleapis.com",
     "meshconfig.googleapis.com",
     "cloudresourcemanager.googleapis.com",
     "monitoring.googleapis.com",
diff --git a/variables.tf b/variables.tf
index 70747fcc8..de94ee0c6 100644
--- a/variables.tf
+++ b/variables.tf
@@ -399,8 +399,8 @@ variable "identity_namespace" {
 
 variable "release_channel" {
   type        = string
-  description = "The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `UNSPECIFIED`."
-  default     = null
+  description = "The release channel of this cluster. Accepted values are `UNSPECIFIED`, `RAPID`, `REGULAR` and `STABLE`. Defaults to `REGULAR`."
+  default     = "REGULAR"
 }
 
 variable "gateway_api_channel" {