diff --git a/x-pack/platform/plugins/private/upgrade_assistant/common/types.ts b/x-pack/platform/plugins/private/upgrade_assistant/common/types.ts
index 9304e54560fd2..50568ea85acbd 100644
--- a/x-pack/platform/plugins/private/upgrade_assistant/common/types.ts
+++ b/x-pack/platform/plugins/private/upgrade_assistant/common/types.ts
@@ -203,6 +203,11 @@ export interface ReindexAction {
    * In future this could be an array of blockers.
    */
   blockerForReindexing?: 'index-closed'; // 'index-closed' can be handled automatically, but requires more resources, user should be warned
+
+  /**
+   * The transform IDs that are currently targeting this index
+   */
+  transformIds?: string[];
 }
 
 export interface UnfreezeAction {
diff --git a/x-pack/platform/plugins/private/upgrade_assistant/public/application/components/es_deprecations/deprecation_types/indices/flyout/container.tsx b/x-pack/platform/plugins/private/upgrade_assistant/public/application/components/es_deprecations/deprecation_types/indices/flyout/container.tsx
index cda76c81b6e2c..c81ff4f132164 100644
--- a/x-pack/platform/plugins/private/upgrade_assistant/public/application/components/es_deprecations/deprecation_types/indices/flyout/container.tsx
+++ b/x-pack/platform/plugins/private/upgrade_assistant/public/application/components/es_deprecations/deprecation_types/indices/flyout/container.tsx
@@ -154,6 +154,7 @@ export const IndexFlyout: React.FunctionComponent<IndexFlyoutProps> = ({
             startReadonly={() => {
               setFlyoutStep('confirmReadonly');
             }}
+            deprecation={deprecation}
             updateIndexState={updateIndexState}
             reindexState={reindexState}
           />
@@ -214,6 +215,7 @@ export const IndexFlyout: React.FunctionComponent<IndexFlyoutProps> = ({
   }, [
     flyoutStep,
     correctiveAction?.type,
+    deprecation,
     closeFlyout,
     updateIndexState,
     reindexState,
diff --git a/x-pack/platform/plugins/private/upgrade_assistant/public/application/components/es_deprecations/deprecation_types/indices/flyout/steps/details/es_transform_target_guidance.tsx b/x-pack/platform/plugins/private/upgrade_assistant/public/application/components/es_deprecations/deprecation_types/indices/flyout/steps/details/es_transform_target_guidance.tsx
new file mode 100644
index 0000000000000..7a674d6d0bc95
--- /dev/null
+++ b/x-pack/platform/plugins/private/upgrade_assistant/public/application/components/es_deprecations/deprecation_types/indices/flyout/steps/details/es_transform_target_guidance.tsx
@@ -0,0 +1,79 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import { i18n } from '@kbn/i18n';
+import { EuiCallOut, EuiLink, EuiText, EuiSpacer } from '@elastic/eui';
+import React from 'react';
+import { FormattedMessage } from '@kbn/i18n-react';
+import type { EnrichedDeprecationInfo } from '../../../../../../../../../common/types';
+import { useAppContext } from '../../../../../../../app_context';
+
+interface Props {
+  deprecation: EnrichedDeprecationInfo;
+}
+
+/**
+ * We get copy directly from ES. This contains information that applies to indices
+ * that are read-only or not.
+ */
+export const ESTransformsTargetGuidance = ({ deprecation }: Props) => {
+  const {
+    services: {
+      core: { http },
+    },
+  } = useAppContext();
+  return (
+    <>
+      <EuiCallOut
+        title={i18n.translate(
+          'xpack.upgradeAssistant.esDeprecations.indices.indexFlyout.detailsStep.esTransform.calloutTitle',
+          { defaultMessage: 'Transforms detected' }
+        )}
+        data-test-subj="esTransformsGuidance"
+        color="warning"
+      >
+        {deprecation.details}
+      </EuiCallOut>
+      <EuiSpacer size="s" />
+      <EuiText size="m">
+        <p>
+          <FormattedMessage
+            id="xpack.upgradeAssistant.esDeprecations.indices.indexFlyout.detailsStep.esTransform.description1"
+            defaultMessage="The reindex operation will copy all of the existing documents into a new index and remove the old one. During the reindex operation your data will be in a read-only state and transforms writing to this index will be paused."
+          />
+        </p>
+        <p>
+          <FormattedMessage
+            id="xpack.upgradeAssistant.esDeprecations.indices.indexFlyout.detailsStep.esTransform.description2"
+            defaultMessage="Depending on size and resources, reindexing may take an extended time. For indices with more than 10GB of data or to avoid transform downtime refer to the {migrationGuideLink} or {transformsLink} to manage transforms writing to this index."
+            values={{
+              migrationGuideLink: (
+                <EuiLink target="_blank" href={deprecation.url}>
+                  {i18n.translate(
+                    'xpack.upgradeAssistant.esDeprecations.indices.indexFlyout.detailsStep.esTransform.migrationGuideLink',
+                    { defaultMessage: 'migration guide' }
+                  )}
+                </EuiLink>
+              ),
+              transformsLink: (
+                <EuiLink
+                  target="_blank"
+                  href={`${http.basePath.prepend('/app/management/data/transform')}`}
+                >
+                  <FormattedMessage
+                    id="xpack.upgradeAssistant.esDeprecations.indices.indexFlyout.detailsStep.esTransform.transfromsLink"
+                    defaultMessage="go to transforms"
+                  />
+                </EuiLink>
+              ),
+            }}
+          />
+        </p>
+      </EuiText>
+    </>
+  );
+};
diff --git a/x-pack/platform/plugins/private/upgrade_assistant/public/application/components/es_deprecations/deprecation_types/indices/flyout/steps/details/reindex_details_step.test.tsx b/x-pack/platform/plugins/private/upgrade_assistant/public/application/components/es_deprecations/deprecation_types/indices/flyout/steps/details/reindex_details_step.test.tsx
index 7861ccd9e482f..2b225299b2772 100644
--- a/x-pack/platform/plugins/private/upgrade_assistant/public/application/components/es_deprecations/deprecation_types/indices/flyout/steps/details/reindex_details_step.test.tsx
+++ b/x-pack/platform/plugins/private/upgrade_assistant/public/application/components/es_deprecations/deprecation_types/indices/flyout/steps/details/reindex_details_step.test.tsx
@@ -12,6 +12,7 @@ import type { ReindexState } from '../../../use_reindex';
 import type { UpdateIndexState } from '../../../use_update_index';
 import { LoadingState } from '../../../../../../types';
 import { cloneDeep } from 'lodash';
+import { EnrichedDeprecationInfo } from '../../../../../../../../../common/types';
 
 jest.mock('../../../../../../../app_context', () => {
   const { docLinksServiceMock } = jest.requireActual('@kbn/core-doc-links-browser-mocks');
@@ -38,6 +39,13 @@ jest.mock('../../../../../../../app_context', () => {
 });
 
 describe('ReindexDetailsFlyoutStep', () => {
+  const deprecation: EnrichedDeprecationInfo = {
+    isCritical: true,
+    message: 'foo',
+    resolveDuringUpgrade: false,
+    type: 'index_settings',
+    url: 'https://te.st',
+  };
   const defaultReindexState: ReindexState = {
     loadingState: LoadingState.Success,
     meta: {
@@ -65,6 +73,7 @@ describe('ReindexDetailsFlyoutStep', () => {
         startReadonly={jest.fn()}
         reindexState={defaultReindexState}
         updateIndexState={defaultUpdateIndexState}
+        deprecation={deprecation}
       />
     );
 
@@ -206,6 +215,94 @@ describe('ReindexDetailsFlyoutStep', () => {
     `);
   });
 
+  it('renders correct guidance for indices with transforms', () => {
+    const wrapper = shallow(
+      <ReindexDetailsFlyoutStep
+        closeFlyout={jest.fn()}
+        startReindex={jest.fn()}
+        startReadonly={jest.fn()}
+        reindexState={defaultReindexState}
+        updateIndexState={defaultUpdateIndexState}
+        deprecation={{
+          ...deprecation,
+          correctiveAction: { type: 'reindex', transformIds: ['abc', 'def'] },
+        }}
+      />
+    );
+    expect(wrapper).toMatchInlineSnapshot(`
+      <Fragment>
+        <EuiFlyoutBody>
+          <EuiText>
+            <ESTransformsTargetGuidance
+              deprecation={
+                Object {
+                  "correctiveAction": Object {
+                    "transformIds": Array [
+                      "abc",
+                      "def",
+                    ],
+                    "type": "reindex",
+                  },
+                  "isCritical": true,
+                  "message": "foo",
+                  "resolveDuringUpgrade": false,
+                  "type": "index_settings",
+                  "url": "https://te.st",
+                }
+              }
+            />
+          </EuiText>
+          <EuiSpacer />
+        </EuiFlyoutBody>
+        <EuiFlyoutFooter>
+          <EuiFlexGroup
+            justifyContent="spaceBetween"
+          >
+            <EuiFlexItem
+              grow={false}
+            >
+              <EuiButtonEmpty
+                flush="left"
+                iconType="cross"
+                onClick={[MockFunction]}
+              >
+                <MemoizedFormattedMessage
+                  defaultMessage="Close"
+                  id="xpack.upgradeAssistant.esDeprecations.indices.indexFlyout.closeButtonLabel"
+                />
+              </EuiButtonEmpty>
+            </EuiFlexItem>
+            <EuiFlexItem
+              grow={false}
+            >
+              <EuiFlexGroup
+                gutterSize="s"
+              >
+                <EuiFlexItem
+                  grow={false}
+                >
+                  <EuiButton
+                    color="primary"
+                    data-test-subj="startReindexingButton"
+                    disabled={false}
+                    fill={true}
+                    isLoading={false}
+                    onClick={[MockFunction]}
+                  >
+                    <MemoizedFormattedMessage
+                      defaultMessage="Start reindexing"
+                      id="xpack.upgradeAssistant.esDeprecations.indices.indexFlyout.detailsStep.reindexButton.runReindexLabel"
+                    />
+                  </EuiButton>
+                </EuiFlexItem>
+              </EuiFlexGroup>
+            </EuiFlexItem>
+          </EuiFlexGroup>
+        </EuiFlyoutFooter>
+      </Fragment>
+    `);
+  });
+
   it('renders for readonly indices (warning deprecation)', () => {
     const props = cloneDeep(defaultReindexState);
     props.meta.isReadonly = true;
@@ -217,6 +314,7 @@ describe('ReindexDetailsFlyoutStep', () => {
         startReadonly={jest.fn()}
         reindexState={props}
         updateIndexState={defaultUpdateIndexState}
+        deprecation={deprecation}
       />
     );
 
diff --git a/x-pack/platform/plugins/private/upgrade_assistant/public/application/components/es_deprecations/deprecation_types/indices/flyout/steps/details/reindex_details_step.tsx b/x-pack/platform/plugins/private/upgrade_assistant/public/application/components/es_deprecations/deprecation_types/indices/flyout/steps/details/reindex_details_step.tsx
index b246081a955e7..0ef7438b38a82 100644
--- a/x-pack/platform/plugins/private/upgrade_assistant/public/application/components/es_deprecations/deprecation_types/indices/flyout/steps/details/reindex_details_step.tsx
+++ b/x-pack/platform/plugins/private/upgrade_assistant/public/application/components/es_deprecations/deprecation_types/indices/flyout/steps/details/reindex_details_step.tsx
@@ -23,7 +23,11 @@ import {
 import { FormattedMessage } from '@kbn/i18n-react';
 import { i18n } from '@kbn/i18n';
 
-import { ReindexStatus } from '../../../../../../../../../common/types';
+import {
+  EnrichedDeprecationInfo,
+  ReindexAction,
+  ReindexStatus,
+} from '../../../../../../../../../common/types';
 import { LoadingState } from '../../../../../../types';
 import type { ReindexState } from '../../../use_reindex';
 import { useAppContext } from '../../../../../../../app_context';
@@ -32,6 +36,7 @@ import { FrozenCallOut } from '../frozen_callout';
 import type { UpdateIndexState } from '../../../use_update_index';
 import { FetchFailedCallOut } from '../fetch_failed_callout';
 import { ReindexingFailedCallOut } from '../reindexing_failed_callout';
+import { ESTransformsTargetGuidance } from './es_transform_target_guidance';
 
 /**
  * Displays a flyout that shows the details / corrective action for a "reindex" deprecation for a given index.
@@ -39,10 +44,18 @@ import { ReindexingFailedCallOut } from '../reindexing_failed_callout';
 export const ReindexDetailsFlyoutStep: React.FunctionComponent<{
   reindexState: ReindexState;
   updateIndexState: UpdateIndexState;
+  deprecation: EnrichedDeprecationInfo;
   startReindex: () => void;
   startReadonly: () => void;
   closeFlyout: () => void;
-}> = ({ reindexState, updateIndexState, startReindex, startReadonly, closeFlyout }) => {
+}> = ({
+  reindexState,
+  updateIndexState,
+  deprecation,
+  startReindex,
+  startReadonly,
+  closeFlyout,
+}) => {
   const {
     services: {
       api,
@@ -57,6 +70,8 @@ export const ReindexDetailsFlyoutStep: React.FunctionComponent<{
   const isCompleted = reindexStatus === ReindexStatus.completed || updateIndexStatus === 'complete';
   const hasFetchFailed = reindexStatus === ReindexStatus.fetchFailed;
   const hasReindexingFailed = reindexStatus === ReindexStatus.failed;
+  const correctiveAction = deprecation.correctiveAction as ReindexAction | undefined;
+  const isESTransformTarget = !!correctiveAction?.transformIds?.length;
 
   const { data: nodes } = api.useLoadNodeDiskSpace();
 
@@ -145,7 +160,8 @@ export const ReindexDetailsFlyoutStep: React.FunctionComponent<{
               </p>
             </Fragment>
           )}
-          {!meta.isReadonly && (
+          {isESTransformTarget && <ESTransformsTargetGuidance deprecation={deprecation} />}
+          {!meta.isReadonly && !isESTransformTarget && (
             <Fragment>
               <p>
                 <FormattedMessage
@@ -252,20 +268,24 @@ export const ReindexDetailsFlyoutStep: React.FunctionComponent<{
           </EuiFlexItem>
           <EuiFlexItem grow={false}>
             <EuiFlexGroup gutterSize="s">
-              {!meta.isReadonly && !hasFetchFailed && !isCompleted && hasRequiredPrivileges && (
-                <EuiFlexItem grow={false}>
-                  <EuiButton
-                    onClick={startReadonly}
-                    disabled={loading}
-                    data-test-subj="startIndexReadonlyButton"
-                  >
-                    <FormattedMessage
-                      id="xpack.upgradeAssistant.esDeprecations.indices.indexFlyout.detailsStep.startIndexReadonlyButton"
-                      defaultMessage="Mark as read-only"
-                    />
-                  </EuiButton>
-                </EuiFlexItem>
-              )}
+              {!meta.isReadonly &&
+                !hasFetchFailed &&
+                !isCompleted &&
+                hasRequiredPrivileges &&
+                !isESTransformTarget && (
+                  <EuiFlexItem grow={false}>
+                    <EuiButton
+                      onClick={startReadonly}
+                      disabled={loading}
+                      data-test-subj="startIndexReadonlyButton"
+                    >
+                      <FormattedMessage
+                        id="xpack.upgradeAssistant.esDeprecations.indices.indexFlyout.detailsStep.startIndexReadonlyButton"
+                        defaultMessage="Mark as read-only"
+                      />
+                    </EuiButton>
+                  </EuiFlexItem>
+                )}
               {!hasFetchFailed && !isCompleted && hasRequiredPrivileges && (
                 <EuiFlexItem grow={false}>
                   <EuiButton
diff --git a/x-pack/platform/plugins/private/upgrade_assistant/server/lib/__fixtures__/fake_deprecations.json b/x-pack/platform/plugins/private/upgrade_assistant/server/lib/__fixtures__/fake_deprecations.json
index bd01c26cf3fb7..5c06b1e68ceda 100644
--- a/x-pack/platform/plugins/private/upgrade_assistant/server/lib/__fixtures__/fake_deprecations.json
+++ b/x-pack/platform/plugins/private/upgrade_assistant/server/lib/__fixtures__/fake_deprecations.json
@@ -164,6 +164,19 @@
         "resolve_during_rolling_upgrade": false
       }
     ],
+    "transforms_index": [
+      {
+        "level": "critical",
+        "message": "Old index with a compatibility version < 8.0",
+        "url": "https://www.elastic.co/guide/en/elasticsearch/reference/master/breaking-changes-9.0.html",
+        "details": "This index has version: 7.17.25",
+        "resolve_during_rolling_upgrade": false,
+        "_meta": {
+          "reindex_required": true,
+          "transform_ids": ["abc"]
+        }
+      }
+    ],
     "myindex": [
       {
         "level": "critical",
diff --git a/x-pack/platform/plugins/private/upgrade_assistant/server/lib/es_deprecations_status/__snapshots__/index.test.ts.snap b/x-pack/platform/plugins/private/upgrade_assistant/server/lib/es_deprecations_status/__snapshots__/index.test.ts.snap
index 1b0fc3a393219..f189759048776 100644
--- a/x-pack/platform/plugins/private/upgrade_assistant/server/lib/es_deprecations_status/__snapshots__/index.test.ts.snap
+++ b/x-pack/platform/plugins/private/upgrade_assistant/server/lib/es_deprecations_status/__snapshots__/index.test.ts.snap
@@ -172,6 +172,22 @@ Object {
       "type": "index_settings",
       "url": "https://www.elastic.co/guide/en/elasticsearch/reference/6.0/breaking_60_mappings_changes.html#_coercion_of_boolean_fields",
     },
+    Object {
+      "correctiveAction": Object {
+        "blockerForReindexing": undefined,
+        "transformIds": Array [
+          "abc",
+        ],
+        "type": "reindex",
+      },
+      "details": "This index has version: 7.17.25",
+      "index": "transforms_index",
+      "isCritical": true,
+      "message": "Old index with a compatibility version < 8.0",
+      "resolveDuringUpgrade": false,
+      "type": "index_settings",
+      "url": "https://www.elastic.co/guide/en/elasticsearch/reference/master/breaking-changes-9.0.html",
+    },
     Object {
       "correctiveAction": Object {
         "blockerForReindexing": undefined,
@@ -216,7 +232,7 @@ Object {
       "url": "https://github.com/elastic/elasticsearch/pull/117172",
     },
   ],
-  "totalCriticalDeprecations": 8,
+  "totalCriticalDeprecations": 9,
   "totalCriticalHealthIssues": 0,
 }
 `;
diff --git a/x-pack/platform/plugins/private/upgrade_assistant/server/lib/es_deprecations_status/get_corrective_actions.ts b/x-pack/platform/plugins/private/upgrade_assistant/server/lib/es_deprecations_status/get_corrective_actions.ts
index 1743a681a808a..d93aa25848e15 100644
--- a/x-pack/platform/plugins/private/upgrade_assistant/server/lib/es_deprecations_status/get_corrective_actions.ts
+++ b/x-pack/platform/plugins/private/upgrade_assistant/server/lib/es_deprecations_status/get_corrective_actions.ts
@@ -21,6 +21,13 @@ interface MlActionMetadata {
   snapshot_id: string;
   job_id: string;
 }
+
+interface IndexActionMetadata {
+  actions?: Action[];
+  reindex_required: boolean;
+  transform_ids: string[];
+}
+
 interface DataStreamActionMetadata {
   actions?: Action[];
   total_backing_indices: number;
@@ -101,8 +108,10 @@ export const getCorrectiveAction = (
   }
 
   if (requiresReindexAction) {
+    const transformIds = (metadata as IndexActionMetadata)?.transform_ids;
     return {
       type: 'reindex',
+      ...(transformIds?.length ? { transformIds } : {}),
     };
   }