diff --git a/README.md b/README.md
index 3ec94e8..4317e7c 100644
--- a/README.md
+++ b/README.md
@@ -7,6 +7,7 @@ This terraform module creates a documentDB cluster.
 
 | Name | Description | Type | Default | Required |
 |------|-------------|:----:|:-----:|:-----:|
+| apply\_immediately | Specifies whether any cluster modifications are applied immediately, or during the next maintenance window. | bool | `"false"` | no |
 | backup\_retention\_period |  | number | `"7"` | no |
 | cluster\_instance\_class |  | string | `"db.r5.large"` | no |
 | cluster\_instance\_count |  | number | `"1"` | no |
diff --git a/main.tf b/main.tf
index cb7fd4a..182bee0 100644
--- a/main.tf
+++ b/main.tf
@@ -12,6 +12,7 @@ resource "aws_docdb_cluster" "api_docdb" {
   master_username                 = var.master_username
   master_password                 = var.master_password
   storage_encrypted               = var.storage_encrypted
+  apply_immediately               = var.apply_immediately
 
   backup_retention_period = var.backup_retention_period
   preferred_backup_window = var.preferred_backup_window
diff --git a/variables.tf b/variables.tf
index 076fa22..287df27 100644
--- a/variables.tf
+++ b/variables.tf
@@ -54,3 +54,9 @@ variable "parameters" {
   type        = list(map(any))
   default     = []
 }
+
+variable "apply_immediately" {
+  default     = false
+  description = "Specifies whether any cluster modifications are applied immediately, or during the next maintenance window."
+  type        = bool
+}