diff --git a/docs/changelog/134711.yaml b/docs/changelog/134711.yaml
new file mode 100644
index 0000000000000..0789eeb4b69df
--- /dev/null
+++ b/docs/changelog/134711.yaml
@@ -0,0 +1,5 @@
+pr: 134711
+summary: Add Reason field to elastic-agent upgrade details metadata
+area: Infra/Plugins
+type: enhancement
+issues: []
diff --git a/x-pack/plugin/core/template-resources/src/main/resources/fleet-agents.json b/x-pack/plugin/core/template-resources/src/main/resources/fleet-agents.json
index 4405b443859d5..fb2c840d72c8f 100644
--- a/x-pack/plugin/core/template-resources/src/main/resources/fleet-agents.json
+++ b/x-pack/plugin/core/template-resources/src/main/resources/fleet-agents.json
@@ -308,6 +308,15 @@
                 },
                 "retry_until": {
                   "type": "date"
+                },
+                "reason": {
+                  "type":"text",
+                  "fields": {
+                    "keyword": {
+                      "type": "keyword",
+                      "ignore_above": 1024
+                    }
+                  }
                 }
               }
             }
diff --git a/x-pack/plugin/fleet/src/main/java/org/elasticsearch/xpack/fleet/Fleet.java b/x-pack/plugin/fleet/src/main/java/org/elasticsearch/xpack/fleet/Fleet.java
index c2a5fe1ebb782..65c207b3855c6 100644
--- a/x-pack/plugin/fleet/src/main/java/org/elasticsearch/xpack/fleet/Fleet.java
+++ b/x-pack/plugin/fleet/src/main/java/org/elasticsearch/xpack/fleet/Fleet.java
@@ -79,7 +79,7 @@ public class Fleet extends Plugin implements SystemIndexPlugin {
     private static final String MAPPING_VERSION_VARIABLE = "fleet.version";
     private static final List<String> ALLOWED_PRODUCTS = List.of("kibana", "fleet");
     private static final int FLEET_ACTIONS_MAPPINGS_VERSION = 2;
-    private static final int FLEET_AGENTS_MAPPINGS_VERSION = 2;
+    private static final int FLEET_AGENTS_MAPPINGS_VERSION = 4;
     private static final int FLEET_ENROLLMENT_API_KEYS_MAPPINGS_VERSION = 3;
     private static final int FLEET_SECRETS_MAPPINGS_VERSION = 1;
     private static final int FLEET_POLICIES_MAPPINGS_VERSION = 2;