diff --git a/x-pack/plugins/ingest_manager/common/types/models/agent.ts b/x-pack/plugins/ingest_manager/common/types/models/agent.ts
index ad06e8d3c9c11..179cc3fc9eb55 100644
--- a/x-pack/plugins/ingest_manager/common/types/models/agent.ts
+++ b/x-pack/plugins/ingest_manager/common/types/models/agent.ts
@@ -56,8 +56,9 @@ interface AgentBase {
   access_api_key_id?: string;
   default_api_key?: string;
   config_id?: string;
+  config_revision?: number;
+  config_newest_revision?: number;
   last_checkin?: string;
-  config_updated_at?: string;
   actions: AgentAction[];
 }
 
diff --git a/x-pack/plugins/ingest_manager/public/applications/ingest_manager/sections/fleet/agent_list_page/index.tsx b/x-pack/plugins/ingest_manager/public/applications/ingest_manager/sections/fleet/agent_list_page/index.tsx
index acf09dedc25f7..14a579eb72598 100644
--- a/x-pack/plugins/ingest_manager/public/applications/ingest_manager/sections/fleet/agent_list_page/index.tsx
+++ b/x-pack/plugins/ingest_manager/public/applications/ingest_manager/sections/fleet/agent_list_page/index.tsx
@@ -26,6 +26,7 @@ import {
   EuiButtonIcon,
   EuiContextMenuPanel,
   EuiContextMenuItem,
+  EuiIcon,
 } from '@elastic/eui';
 import { i18n } from '@kbn/i18n';
 import { FormattedMessage, FormattedRelative } from '@kbn/i18n/react';
@@ -289,6 +290,7 @@ export const AgentListPage: React.FunctionComponent<{}> = () => {
     },
     {
       field: 'active',
+      width: '100px',
       name: i18n.translate('xpack.ingestManager.agentList.statusColumnTitle', {
         defaultMessage: 'Status',
       }),
@@ -299,10 +301,10 @@ export const AgentListPage: React.FunctionComponent<{}> = () => {
       name: i18n.translate('xpack.ingestManager.agentList.configColumnTitle', {
         defaultMessage: 'Configuration',
       }),
-      render: (configId: string) => {
+      render: (configId: string, agent: Agent) => {
         const configName = agentConfigs.find(p => p.id === configId)?.name;
         return (
-          <EuiFlexGroup gutterSize="s" alignItems="baseline" style={{ minWidth: 0 }}>
+          <EuiFlexGroup gutterSize="s" alignItems="center" style={{ minWidth: 0 }}>
             <EuiFlexItem grow={false} style={NO_WRAP_TRUNCATE_STYLE}>
               <EuiLink
                 href={`${CONFIG_DETAILS_URI}${configId}`}
@@ -312,21 +314,42 @@ export const AgentListPage: React.FunctionComponent<{}> = () => {
                 {configName || configId}
               </EuiLink>
             </EuiFlexItem>
-            <EuiFlexItem grow={true}>
-              <EuiText color="subdued" size="xs" style={{ whiteSpace: 'nowrap' }}>
-                <FormattedMessage
-                  id="xpack.ingestManager.agentList.revisionNumber"
-                  defaultMessage="rev. {revNumber}"
-                  values={{ revNumber: '999' }} // TODO fix when we have revision
-                />
-              </EuiText>
-            </EuiFlexItem>
+            {agent.config_revision && (
+              <EuiFlexItem grow={false}>
+                <EuiText color="default" size="xs" className="eui-textNoWrap">
+                  <FormattedMessage
+                    id="xpack.ingestManager.agentList.revisionNumber"
+                    defaultMessage="rev. {revNumber}"
+                    values={{ revNumber: agent.config_revision }}
+                  />
+                </EuiText>
+              </EuiFlexItem>
+            )}
+            {agent.config_revision &&
+              agent.config_newest_revision &&
+              agent.config_newest_revision > agent.config_revision && (
+                <EuiFlexItem grow={false}>
+                  <EuiText color="subdued" size="xs" className="eui-textNoWrap">
+                    <EuiIcon size="m" type="alert" color="warning" />
+                    &nbsp;
+                    {true && (
+                      <>
+                        <FormattedMessage
+                          id="xpack.ingestManager.agentList.outOfDateLabel"
+                          defaultMessage="Out-of-date"
+                        />
+                      </>
+                    )}
+                  </EuiText>
+                </EuiFlexItem>
+              )}
           </EuiFlexGroup>
         );
       },
     },
     {
       field: 'local_metadata.agent_version',
+      width: '100px',
       name: i18n.translate('xpack.ingestManager.agentList.versionTitle', {
         defaultMessage: 'Version',
       }),
diff --git a/x-pack/plugins/ingest_manager/server/saved_objects.ts b/x-pack/plugins/ingest_manager/server/saved_objects.ts
index 860b95b58c7f7..31cf173c3e4f9 100644
--- a/x-pack/plugins/ingest_manager/server/saved_objects.ts
+++ b/x-pack/plugins/ingest_manager/server/saved_objects.ts
@@ -32,7 +32,8 @@ export const savedObjectMappings = {
       config_id: { type: 'keyword' },
       last_updated: { type: 'date' },
       last_checkin: { type: 'date' },
-      config_updated_at: { type: 'date' },
+      config_revision: { type: 'integer' },
+      config_newest_revision: { type: 'integer' },
       // FIXME_INGEST https://github.com/elastic/kibana/issues/56554
       default_api_key: { type: 'keyword' },
       updated_at: { type: 'date' },
diff --git a/x-pack/plugins/ingest_manager/server/services/agents/acks.ts b/x-pack/plugins/ingest_manager/server/services/agents/acks.ts
index 98a5f69f9d2b0..cf9a47979ae8b 100644
--- a/x-pack/plugins/ingest_manager/server/services/agents/acks.ts
+++ b/x-pack/plugins/ingest_manager/server/services/agents/acks.ts
@@ -51,8 +51,22 @@ export async function acknowledgeAgentActions(
   });
 
   if (matchedUpdatedActions.length > 0) {
+    const configRevision = matchedUpdatedActions.reduce((acc, action) => {
+      if (action.type !== 'CONFIG_CHANGE') {
+        return acc;
+      }
+      const data = action.data ? JSON.parse(action.data as string) : {};
+
+      if (data?.config?.id !== agent.config_id) {
+        return acc;
+      }
+
+      return data?.config?.revision > acc ? data?.config?.revision : acc;
+    }, agent.config_revision || 0);
+
     await soClient.update<AgentSOAttributes>(AGENT_SAVED_OBJECT_TYPE, agent.id, {
       actions: matchedUpdatedActions,
+      config_revision: configRevision,
     });
   }
 
diff --git a/x-pack/plugins/ingest_manager/server/services/agents/checkin.test.ts b/x-pack/plugins/ingest_manager/server/services/agents/checkin.test.ts
new file mode 100644
index 0000000000000..d3e10fcb6b63f
--- /dev/null
+++ b/x-pack/plugins/ingest_manager/server/services/agents/checkin.test.ts
@@ -0,0 +1,117 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+import { shouldCreateConfigAction } from './checkin';
+import { Agent } from '../../types';
+
+function getAgent(data: Partial<Agent>) {
+  return { actions: [], ...data } as Agent;
+}
+
+describe('Agent checkin service', () => {
+  describe('shouldCreateConfigAction', () => {
+    it('should return false if the agent do not have an assigned config', () => {
+      const res = shouldCreateConfigAction(getAgent({}));
+
+      expect(res).toBeFalsy();
+    });
+
+    it('should return true if this is agent first checkin', () => {
+      const res = shouldCreateConfigAction(getAgent({ config_id: 'config1' }));
+
+      expect(res).toBeTruthy();
+    });
+
+    it('should return false agent is already running latest revision', () => {
+      const res = shouldCreateConfigAction(
+        getAgent({
+          config_id: 'config1',
+          last_checkin: '2018-01-02T00:00:00',
+          config_revision: 1,
+          config_newest_revision: 1,
+        })
+      );
+
+      expect(res).toBeFalsy();
+    });
+
+    it('should return false agent has already latest revision config change action', () => {
+      const res = shouldCreateConfigAction(
+        getAgent({
+          config_id: 'config1',
+          last_checkin: '2018-01-02T00:00:00',
+          config_revision: 1,
+          config_newest_revision: 2,
+          actions: [
+            {
+              id: 'action1',
+              type: 'CONFIG_CHANGE',
+              created_at: new Date().toISOString(),
+              data: JSON.stringify({
+                config: {
+                  id: 'config1',
+                  revision: 2,
+                },
+              }),
+            },
+          ],
+        })
+      );
+
+      expect(res).toBeFalsy();
+    });
+
+    it('should return true agent has unrelated config change actions', () => {
+      const res = shouldCreateConfigAction(
+        getAgent({
+          config_id: 'config1',
+          last_checkin: '2018-01-02T00:00:00',
+          config_revision: 1,
+          config_newest_revision: 2,
+          actions: [
+            {
+              id: 'action1',
+              type: 'CONFIG_CHANGE',
+              created_at: new Date().toISOString(),
+              data: JSON.stringify({
+                config: {
+                  id: 'config2',
+                  revision: 2,
+                },
+              }),
+            },
+            {
+              id: 'action1',
+              type: 'CONFIG_CHANGE',
+              created_at: new Date().toISOString(),
+              data: JSON.stringify({
+                config: {
+                  id: 'config1',
+                  revision: 1,
+                },
+              }),
+            },
+          ],
+        })
+      );
+
+      expect(res).toBeTruthy();
+    });
+
+    it('should return true if this agent has a new revision', () => {
+      const res = shouldCreateConfigAction(
+        getAgent({
+          config_id: 'config1',
+          last_checkin: '2018-01-02T00:00:00',
+          config_revision: 1,
+          config_newest_revision: 2,
+        })
+      );
+
+      expect(res).toBeTruthy();
+    });
+  });
+});
diff --git a/x-pack/plugins/ingest_manager/server/services/agents/checkin.ts b/x-pack/plugins/ingest_manager/server/services/agents/checkin.ts
index 0ff4af4ffe351..d80fff5d8eceb 100644
--- a/x-pack/plugins/ingest_manager/server/services/agents/checkin.ts
+++ b/x-pack/plugins/ingest_manager/server/services/agents/checkin.ts
@@ -37,7 +37,7 @@ export async function agentCheckin(
   const actions = filterActionsForCheckin(agent);
 
   // Generate new agent config if config is updated
-  if (isNewAgentConfig(agent) && agent.config_id) {
+  if (agent.config_id && shouldCreateConfigAction(agent)) {
     const config = await agentConfigService.getFullConfig(soClient, agent.config_id);
     if (config) {
       // Assign output API keys
@@ -149,12 +149,37 @@ function isActionEvent(event: AgentEvent) {
   );
 }
 
-function isNewAgentConfig(agent: Agent) {
+export function shouldCreateConfigAction(agent: Agent): boolean {
+  if (!agent.config_id) {
+    return false;
+  }
+
   const isFirstCheckin = !agent.last_checkin;
-  const isConfigUpdatedSinceLastCheckin =
-    agent.last_checkin && agent.config_updated_at && agent.last_checkin <= agent.config_updated_at;
+  if (isFirstCheckin) {
+    return true;
+  }
+
+  const isAgentConfigOutdated =
+    agent.config_revision &&
+    agent.config_newest_revision &&
+    agent.config_revision < agent.config_newest_revision;
+  if (!isAgentConfigOutdated) {
+    return false;
+  }
+
+  const isActionAlreadyGenerated = !!agent.actions.find(action => {
+    if (!action.data || action.type !== 'CONFIG_CHANGE') {
+      return false;
+    }
+
+    const data = JSON.parse(action.data);
+
+    return (
+      data.config.id === agent.config_id && data.config.revision === agent.config_newest_revision
+    );
+  });
 
-  return isFirstCheckin || isConfigUpdatedSinceLastCheckin;
+  return !isActionAlreadyGenerated;
 }
 
 function filterActionsForCheckin(agent: Agent): AgentAction[] {
diff --git a/x-pack/plugins/ingest_manager/server/services/agents/enroll.ts b/x-pack/plugins/ingest_manager/server/services/agents/enroll.ts
index 0f73f71817eb0..52547e9bcb0fb 100644
--- a/x-pack/plugins/ingest_manager/server/services/agents/enroll.ts
+++ b/x-pack/plugins/ingest_manager/server/services/agents/enroll.ts
@@ -37,7 +37,6 @@ export async function enroll(
     current_error_events: undefined,
     actions: [],
     access_api_key_id: undefined,
-    config_updated_at: undefined,
     last_checkin: undefined,
     default_api_key: undefined,
   };
diff --git a/x-pack/plugins/ingest_manager/server/services/agents/update.ts b/x-pack/plugins/ingest_manager/server/services/agents/update.ts
index 9eabf0944bdc4..59d0ad31d1a64 100644
--- a/x-pack/plugins/ingest_manager/server/services/agents/update.ts
+++ b/x-pack/plugins/ingest_manager/server/services/agents/update.ts
@@ -8,14 +8,18 @@ import { SavedObjectsClientContract } from 'src/core/server';
 import { listAgents } from './crud';
 import { AGENT_SAVED_OBJECT_TYPE } from '../../constants';
 import { unenrollAgents } from './unenroll';
+import { agentConfigService } from '../agent_config';
 
 export async function updateAgentsForConfigId(
   soClient: SavedObjectsClientContract,
   configId: string
 ) {
+  const config = await agentConfigService.get(soClient, configId);
+  if (!config) {
+    throw new Error('Config not found');
+  }
   let hasMore = true;
   let page = 1;
-  const now = new Date().toISOString();
   while (hasMore) {
     const { agents } = await listAgents(soClient, {
       kuery: `agents.config_id:"${configId}"`,
@@ -30,7 +34,7 @@ export async function updateAgentsForConfigId(
     const agentUpdate = agents.map(agent => ({
       id: agent.id,
       type: AGENT_SAVED_OBJECT_TYPE,
-      attributes: { config_updated_at: now },
+      attributes: { config_newest_revision: config.revision },
     }));
 
     await soClient.bulkUpdate(agentUpdate);