diff --git a/clusters/csvd-lab-dja/main.tf b/clusters/csvd-lab-dja/main.tf
new file mode 100644
index 0000000..7972a23
--- /dev/null
+++ b/clusters/csvd-lab-dja/main.tf
@@ -0,0 +1,60 @@
+provider "aws" {
+}
+
+data "aws_secretsmanager_secret_version" "github_token" {
+  secret_id = "/eks-cluster-deployment/github_token"
+}
+
+provider "github" {
+  token = data.aws_secretsmanager_secret_version.github_token.secret_string
+}
+
+module "eks_deployment" {
+  source          = "../../"
+  repository_mode = "create"
+  organization    = "SCT-Engineering"
+
+  # Repository and cluster configuration - single name for both
+  name        = "csvd-lab-dja"
+  environment = "lab"
+  region      = "us-gov-east-1"
+
+  # Cluster configuration - simplified interface
+  cluster_config = {
+    account_name          = "lab-dev-gov"
+    aws_account_id        = "224384469011"
+    cluster_mailing_list  = "matthew.c.morgan@census.gov"
+    environment_abbr      = "lab"
+    finops_project_name   = "csvd_platformbaseline"
+    finops_project_number = "fs0000000078"
+    finops_project_role   = "csvd_platformbaseline_eks"
+    vpc_domain_name       = "dev.lab.csp2.census.gov"
+    vpc_name              = "vpc3-lab-dev"
+    tags = {
+      Owner       = "matthew.c.morgan@census.gov"
+      Environment = "lab"
+      CostCenter  = "fs0000000078"
+    }
+    organization = "census:ocio:csvd"
+  }
+  template_enabled_modules = {
+    eks-gatekeeper = false
+    eks-grafana    = false
+    eks-kiali      = false
+    eks-keycloak   = false
+    eks-loki       = false
+    eks-otel       = false
+    eks-prometheus = false
+    eks-tempo      = false
+  }
+}
+
+output "repository_url" {
+  description = "URL of the created GitHub repository"
+  value       = module.eks_deployment.repository_url
+}
+
+output "ssh_clone_url" {
+  description = "SSH clone URL of the repository"
+  value       = module.eks_deployment.ssh_clone_url
+}
diff --git a/clusters/csvd-lab-mcm/main.tf b/clusters/csvd-lab-mcm/main.tf
index 09ed437..4b16870 100644
--- a/clusters/csvd-lab-mcm/main.tf
+++ b/clusters/csvd-lab-mcm/main.tf
@@ -11,12 +11,12 @@ provider "github" {
 
 module "eks_deployment" {
   source          = "../../"
-  repository_mode = "create"
+  repository_mode = "update"
   organization    = "SCT-Engineering"
 
   # Repository and cluster configuration - single name for both
   name        = "csvd-lab-mcm"
-  environment = "dev"
+  environment = "lab"
   region      = "us-gov-east-1"
 
   # Cluster configuration - simplified interface
@@ -32,7 +32,7 @@ module "eks_deployment" {
     vpc_name              = "vpc3-lab-dev"
     tags = {
       Owner       = "matthew.c.morgan@census.gov"
-      Environment = "development"
+      Environment = "lab"
       CostCenter  = "fs0000000078"
     }
     organization = "census:ocio:csvd"
diff --git a/main.tf b/main.tf
index 6aab949..c7f8752 100644
--- a/main.tf
+++ b/main.tf
@@ -1,6 +1,7 @@
 locals {
-  create_repository      = var.repository_mode == "create"
+  create_repository      = lower(trimspace(var.repository_mode)) == "create"
   effective_files_branch = local.create_repository ? "new/${var.name}" : "update/${var.name}"
+  update_source_branch   = var.files_branch_source_branch != null ? var.files_branch_source_branch : (local.create_repository ? null : data.github_repository.existing_repo[0].default_branch)
   effective_template_enabled_modules = merge(var.template_enabled_modules, {
     eks           = true
     eks-config    = true
@@ -57,6 +58,7 @@ locals {
         eks_ng_max_size        = local.eks_defaults.ng_max_size
         eks_ng_min_size        = local.eks_defaults.ng_min_size
         organization           = var.cluster_config.organization
+        CostAllocation         = var.cluster_config.organization
         finops_project_name    = local.organization_defaults.finops_project_name
         finops_project_number  = local.organization_defaults.finops_project_number
         finops_project_role    = local.organization_defaults.finops_project_role
@@ -105,6 +107,35 @@ locals {
       aws_region   = var.region
     })
   }
+
+  desired_managed_files_by_path = {
+    for file in concat([
+      for path, content in local.rendered_files : {
+        path    = path
+        content = content
+      }
+      ],
+      local.template_cluster_sync_files,
+      local.managed_extra_files
+    ) : file.path => file.content
+  }
+
+  existing_managed_file_paths = !local.create_repository && local.update_source_branch != null ? toset([
+    for entry in data.github_tree.update_source_branch_tree[0].entries : entry.path
+    if entry.type == "blob"
+  ]) : toset([])
+
+  managed_files_requiring_update = local.create_repository ? local.desired_managed_files_by_path : {
+    for path, content in local.desired_managed_files_by_path : path => content
+    if !contains(local.existing_managed_file_paths, path) || data.github_repository_file.existing_managed_files[path].content != content
+  }
+
+  has_update_changes            = length(local.managed_files_requiring_update) > 0
+  effective_update_files_branch = local.create_repository || local.has_update_changes ? local.effective_files_branch : null
+  managed_extra_files_for_module = [for path, content in local.managed_files_requiring_update : {
+    path    = path
+    content = content
+  }]
 }
 
 data "github_repository" "existing_repo" {
@@ -112,6 +143,30 @@ data "github_repository" "existing_repo" {
   full_name = "${var.organization}/${var.name}"
 }
 
+# Used to detect accidental create-mode runs against an already-existing repo.
+data "github_repositories" "create_mode_check" {
+  count = local.create_repository ? 1 : 0
+  query = "org:${var.organization} ${var.name} in:name"
+}
+
+locals {
+  create_mode_repo_exists = local.create_repository && contains(
+    try(data.github_repositories.create_mode_check[0].names, []),
+    var.name
+  )
+}
+
+resource "terraform_data" "create_mode_guard" {
+  count = local.create_repository ? 1 : 0
+
+  lifecycle {
+    precondition {
+      condition     = !local.create_mode_repo_exists
+      error_message = "repository_mode=\"create\" is set but repository \"${var.name}\" already exists in ${var.organization}. Switch to repository_mode=\"update\"."
+    }
+  }
+}
+
 data "github_repository_file" "template_cluster_files" {
   for_each = toset(var.template_cluster_file_paths)
 
@@ -120,25 +175,42 @@ data "github_repository_file" "template_cluster_files" {
   file       = "environment/region/vpc/cluster/${each.value}"
 }
 
-resource "github_branch" "files_branch" {
-  count         = !local.create_repository ? 1 : 0
-  repository    = var.name
-  branch        = local.effective_files_branch
-  source_branch = var.files_branch_source_branch != null ? var.files_branch_source_branch : data.github_repository.existing_repo[0].default_branch
+data "github_tree" "update_source_branch_tree" {
+  count = !local.create_repository && local.update_source_branch != null ? 1 : 0
+
+  repository = var.name
+  tree_sha   = local.update_source_branch
+  recursive  = true
+
+  depends_on = [
+    data.github_repository.existing_repo,
+  ]
+}
+
+data "github_repository_file" "existing_managed_files" {
+  for_each = !local.create_repository ? {
+    for path, content in local.desired_managed_files_by_path : path => content
+    if contains(local.existing_managed_file_paths, path)
+  } : {}
+
+  repository = "${var.organization}/${var.name}"
+  branch     = coalesce(local.update_source_branch, "main")
+  file       = each.key
 }
 
 module "github_repo" {
   source = "../terraform-github-repo"
 
-  name                    = var.name
-  repo_org                = var.organization
-  create_repo             = local.create_repository
-  create_codeowners       = true
-  enforce_prs             = true
-  files_branch            = local.effective_files_branch
-  github_repo_description = "EKS Cluster Configuration for ${var.name}"
-  github_repo_topics      = ["eks", "kubernetes", "terraform", "infrastructure"]
-  force_name              = var.force_name
+  name                       = var.name
+  repo_org                   = var.organization
+  create_repo                = local.create_repository
+  create_codeowners          = true
+  enforce_prs                = true
+  files_branch               = local.effective_update_files_branch
+  files_branch_source_branch = local.update_source_branch
+  github_repo_description    = "EKS Cluster Configuration for ${var.name}"
+  github_repo_topics         = ["eks", "kubernetes", "terraform", "infrastructure"]
+  force_name                 = var.force_name
 
   template_repo_org = null
   template_repo     = null
@@ -149,15 +221,7 @@ module "github_repo" {
   github_has_projects  = true
   vulnerability_alerts = null
 
-  managed_extra_files = concat([
-    for path, content in local.rendered_files : {
-      path    = path
-      content = content
-    }],
-    local.template_cluster_sync_files,
-    local.managed_extra_files,
-    var.github_actions_workflows
-  )
+  managed_extra_files = local.managed_extra_files_for_module
 
   archive_on_destroy = false
   github_org_teams = [
@@ -170,9 +234,6 @@ module "github_repo" {
     }
   ]
 
-  depends_on = [
-    github_branch.files_branch
-  ]
 }
 
 # The EKS deployment logic will go here, and will be skipped if create_repository is true.
diff --git a/templates/cluster.hcl.tf.tpl b/templates/cluster.hcl.tf.tpl
index 0a30d6c..0d8c524 100644
--- a/templates/cluster.hcl.tf.tpl
+++ b/templates/cluster.hcl.tf.tpl
@@ -7,6 +7,7 @@ locals {
   eks_ng_max_size           = ${eks_ng_max_size}
   eks_ng_min_size           = ${eks_ng_min_size}
   organization              = "${organization}"
+  CostAllocation            = "${organization}"
   finops_project_name       = "${finops_project_name}"
   finops_project_number     = "${finops_project_number}"
   finops_project_role       = "${finops_project_role}"
diff --git a/templates/root.hcl.tf.tpl b/templates/root.hcl.tf.tpl
index 981f885..d4f7bf1 100644
--- a/templates/root.hcl.tf.tpl
+++ b/templates/root.hcl.tf.tpl
@@ -142,7 +142,9 @@ generate "aws-provider" {
         finops_project_name = "$${local.finops_project_name}"
         finops_project_number = "$${local.finops_project_number}"
         finops_project_role = "$${local.finops_project_role}"
+        CostAllocation = "$${local.organization}"
         organization = "$${local.organization}"
+        "boc:created-by" = "terragrunt"
       }
     }
     # Only these AWS Account IDs may be operated on by this template
@@ -151,6 +153,19 @@ generate "aws-provider" {
 EOF
 }
 
+generate "tags-yml" {
+  path      = "tags.yml"
+  if_exists = "overwrite"
+  contents  = !local.is_eks_module ? "" : <<-EOF
+  finops:
+    number: "$${tonumber(regex("[0-9]+$", local.finops_project_number))}"
+    name: "$${local.finops_project_name}"
+    roles:
+      - eks
+      - "$${local.finops_project_role}"
+  EOF
+}
+
 # ---------------------------------------------------------------------------------------------------------------------
 # GLOBAL PARAMETERS
 # These variables apply to all configurations in this subfolder. These are automatically merged into the child
diff --git a/variables.tf b/variables.tf
index 48db28b..da70bfd 100644
--- a/variables.tf
+++ b/variables.tf
@@ -258,7 +258,7 @@ variable "repository_mode" {
   default     = "create"
 
   validation {
-    condition     = contains(["create", "update"], var.repository_mode)
+    condition     = contains(["create", "update"], lower(trimspace(var.repository_mode)))
     error_message = "repository_mode must be either 'create' or 'update'."
   }
 }