diff --git a/smithy-aws-traits/src/main/java/software/amazon/smithy/aws/traits/tagging/TaggableResourceValidator.java b/smithy-aws-traits/src/main/java/software/amazon/smithy/aws/traits/tagging/TaggableResourceValidator.java
index 417bc1627e6..2dfa663aded 100644
--- a/smithy-aws-traits/src/main/java/software/amazon/smithy/aws/traits/tagging/TaggableResourceValidator.java
+++ b/smithy-aws-traits/src/main/java/software/amazon/smithy/aws/traits/tagging/TaggableResourceValidator.java
@@ -43,14 +43,23 @@ public List<ValidationEvent> validate(Model model) {
         List<ValidationEvent> events = new LinkedList<>();
         TopDownIndex topDownIndex = TopDownIndex.of(model);
         AwsTagIndex tagIndex = AwsTagIndex.of(model);
-        for (ServiceShape service : model.getServiceShapesWithTrait(TagEnabledTrait.class)) {
+        for (ServiceShape service : model.getServiceShapes()) {
             for (ResourceShape resource : topDownIndex.getContainedResources(service)) {
+                boolean resourceLikelyTaggable = false;
                 if (resource.hasTrait(TaggableTrait.class)) {
                     events.addAll(validateResource(model, resource, service, tagIndex));
-                } else if (resource.hasTrait(ArnTrait.class) && tagIndex.serviceHasTagApis(service.getId())) {
+                    resourceLikelyTaggable = true;
+                } else if (resource.hasTrait(ArnTrait.class) && tagIndex.serviceHasTagApis(service)) {
                     // If a resource does not have the taggable trait, but has an ARN, and the service has tag
                     // operations, it is most likely a mistake.
                     events.add(warning(resource, "Resource is likely missing `aws.api#taggable` trait."));
+                    resourceLikelyTaggable = true;
+                }
+
+                // It's possible the resource was marked as taggable but the service isn't tagEnabled.
+                if (resourceLikelyTaggable && !service.hasTrait(TagEnabledTrait.class)) {
+                    events.add(warning(service, "Service has resources with `aws.api#taggable` applied but does not "
+                            + "have the `aws.api#tagEnabled` trait."));
                 }
             }
         }
diff --git a/smithy-aws-traits/src/test/resources/software/amazon/smithy/aws/traits/errorfiles/tagging/tagging-warnings.errors b/smithy-aws-traits/src/test/resources/software/amazon/smithy/aws/traits/errorfiles/tagging/tagging-warnings.errors
index eb96150771a..494564873da 100644
--- a/smithy-aws-traits/src/test/resources/software/amazon/smithy/aws/traits/errorfiles/tagging/tagging-warnings.errors
+++ b/smithy-aws-traits/src/test/resources/software/amazon/smithy/aws/traits/errorfiles/tagging/tagging-warnings.errors
@@ -3,3 +3,4 @@
 [WARNING] example.weather#Weather: Service marked `aws.api#TagEnabled` is missing an operation named 'UntagResource.' | ServiceTagging
 [WARNING] example.weather#City: Suggested tag property name is '[T|t]ags'. | TagResourcePropertyName
 [DANGER] example.weather#UpdateCity: Update and put resource lifecycle operations should not support updating tags because it is a privileged operation that modifies access. | TaggableResource
+[WARNING] example.weather#Weather2: Service has resources with `aws.api#taggable` applied but does not have the `aws.api#tagEnabled` trait. | TaggableResource
diff --git a/smithy-aws-traits/src/test/resources/software/amazon/smithy/aws/traits/errorfiles/tagging/tagging-warnings.smithy b/smithy-aws-traits/src/test/resources/software/amazon/smithy/aws/traits/errorfiles/tagging/tagging-warnings.smithy
index b15aeecee53..420f0c5882f 100644
--- a/smithy-aws-traits/src/test/resources/software/amazon/smithy/aws/traits/errorfiles/tagging/tagging-warnings.smithy
+++ b/smithy-aws-traits/src/test/resources/software/amazon/smithy/aws/traits/errorfiles/tagging/tagging-warnings.smithy
@@ -19,6 +19,11 @@ service Weather {
     operations: [GetCurrentTime]
 }
 
+service Weather2 {
+    version: "2006-03-01",
+    resources: [City]
+}
+
 structure Tag {
     key: String
     value: String