diff --git a/.changelog/29999.txt b/.changelog/29999.txt
new file mode 100644
index 000000000000..ff1ec5c4f962
--- /dev/null
+++ b/.changelog/29999.txt
@@ -0,0 +1,3 @@
+```release-note:bug    
+resource/aws_neptune_cluster: Change lower bound validation for `serverless_v2_scaling_configuration.min_capacity` to 1 Neptune Capacity Unit (NCU)
+```
diff --git a/internal/service/neptune/cluster.go b/internal/service/neptune/cluster.go
index 0245e4788b11..22193e391ddd 100644
--- a/internal/service/neptune/cluster.go
+++ b/internal/service/neptune/cluster.go
@@ -31,8 +31,9 @@ const (
 
 	DefaultPort = 8182
 
-	ServerlessMinNCUs = 2.5
-	ServerlessMaxNCUs = 128.0
+	oldServerlessMinNCUs = 2.5
+	ServerlessMinNCUs    = 1.0
+	ServerlessMaxNCUs    = 128.0
 )
 
 // @SDKResource("aws_neptune_cluster")
@@ -253,8 +254,8 @@ func ResourceCluster() *schema.Resource {
 						"min_capacity": {
 							Type:     schema.TypeFloat,
 							Optional: true,
-							Default:  ServerlessMinNCUs,
-							// Minimum capacity is 2.5 NCUs
+							Default:  oldServerlessMinNCUs,
+							// Minimum capacity is 1.0 NCU
 							// see: https://docs.aws.amazon.com/neptune/latest/userguide/neptune-serverless-capacity-scaling.html
 							ValidateFunc: validation.FloatAtLeast(ServerlessMinNCUs),
 						},
diff --git a/website/docs/r/neptune_cluster.html.markdown b/website/docs/r/neptune_cluster.html.markdown
index 7e4e5f933665..933081620654 100644
--- a/website/docs/r/neptune_cluster.html.markdown
+++ b/website/docs/r/neptune_cluster.html.markdown
@@ -94,7 +94,7 @@ resource "aws_neptune_cluster_instance" "example" {
 }
 ```
 
-* `min_capacity`: (default: **2.5**) The minimum Neptune Capacity Units (NCUs) for this cluster. Must be greater or equal than **2.5**. See [AWS Documentation](https://docs.aws.amazon.com/neptune/latest/userguide/neptune-serverless-capacity-scaling.html) for more details.
+* `min_capacity`: (default: **2.5**) The minimum Neptune Capacity Units (NCUs) for this cluster. Must be greater or equal than **1**. See [AWS Documentation](https://docs.aws.amazon.com/neptune/latest/userguide/neptune-serverless-capacity-scaling.html) for more details.
 * `max_capacity`: (default: **128**) The maximum Neptune Capacity Units (NCUs) for this cluster. Must be lower or equal than **128**. See [AWS Documentation](https://docs.aws.amazon.com/neptune/latest/userguide/neptune-serverless-capacity-scaling.html) for more details.
 
 ## Attributes Reference