diff --git a/.changeset/silver-animals-buy.md b/.changeset/silver-animals-buy.md
new file mode 100644
index 000000000..bee12facb
--- /dev/null
+++ b/.changeset/silver-animals-buy.md
@@ -0,0 +1,5 @@
+---
+"@effect-app/vue-components": patch
+---
+
+fix: preserve user selections when updating tag defaults in OmegaTaggedUnionInternal
diff --git a/packages/vue-components/src/components/OmegaForm/OmegaTaggedUnionInternal.vue b/packages/vue-components/src/components/OmegaForm/OmegaTaggedUnionInternal.vue
index 30a2c8553..48ca4c3e4 100644
--- a/packages/vue-components/src/components/OmegaForm/OmegaTaggedUnionInternal.vue
+++ b/packages/vue-components/src/components/OmegaForm/OmegaTaggedUnionInternal.vue
@@ -34,8 +34,11 @@ watch(() => props.state, (newTag, oldTag) => {
     nextTick(() => {
       // Get default values for the new tag to ensure correct types
       const tagDefaults = (props.form as any).unionDefaultValues?.[newTag as string] ?? {}
-      // Merge: keep _tag from current values, but use tag defaults for other fields
+      // Get current form values to preserve user's selections (e.g., carrier)
+      const currentValues = props.form.state.values
+      // Merge: keep current values, override with tag defaults for type correctness, set new _tag
       const resetValues = {
+        ...currentValues,
         ...tagDefaults,
         _tag: newTag
       }