diff --git a/README.md b/README.md
index eb4713d..74077bc 100644
--- a/README.md
+++ b/README.md
@@ -3,6 +3,7 @@
 This action allows caching dependencies and build outputs to improve workflow execution time.
 
 >Two other actions are available in addition to the primary `cache` action:
+>
 >* [Restore action](./restore/README.md)
 >* [Save action](./save/README.md)
 
@@ -14,6 +15,22 @@ See ["Caching dependencies to speed up workflows"](https://docs.github.com/en/ac
 
 ## What's New
 
+### ⚠️ Important changes
+
+The cache backend service has been rewritten from the ground up for improved performance and reliability. [actions/cache](https://github.com/actions/cache) now integrates with the new cache service (v2) APIs.
+
+The new service will gradually roll out as of **February 1st, 2025**. The legacy service will also be sunset on the same date. Changes in these release are **fully backward compatible**.
+
+**We are deprecating some versions of this action**. We recommend upgrading to version `v4` or `v3` as soon as possible before **February 1st, 2025.** (Upgrade instructions below).
+
+If you are using pinned SHAs, please use the SHAs of versions `v4.2.0` or `v3.4.0`
+
+If you do not upgrade, all workflow runs using any of the deprecated [actions/cache](https://github.com/actions/cache) will fail.
+
+Upgrading to the recommended versions will not break your workflows.
+
+Read more about the change & access the migration guide: [reference to the announcement](https://github.com/actions/cache/discussions/1510).
+
 ### v4
 
 * Updated to node 20
diff --git a/RELEASES.md b/RELEASES.md
index 3188c6b..15b0a2f 100644
--- a/RELEASES.md
+++ b/RELEASES.md
@@ -1,5 +1,19 @@
 # Releases
 
+### 4.2.0
+
+TLDR; The cache backend service has been rewritten from the ground up for improved performance and reliability. [actions/cache](https://github.com/actions/cache) now integrates with the new cache service (v2) APIs.
+
+The new service will gradually roll out as of **February 1st, 2025**. The legacy service will also be sunset on the same date. Changes in these release are **fully backward compatible**.
+
+**We are deprecating some versions of this action**. We recommend upgrading to version `v4` or `v3` as soon as possible before **February 1st, 2025.** (Upgrade instructions below).
+
+If you are using pinned SHAs, please use the SHAs of versions `v4.2.0` or `v3.4.0`
+
+If you do not upgrade, all workflow runs using any of the deprecated [actions/cache](https://github.com/actions/cache) will fail.
+
+Upgrading to the recommended versions will not break your workflows.
+
 ### 4.1.2
 
 - Add GitHub Enterprise Cloud instances hostname filters to inform API endpoint choices - [#1474](https://github.com/actions/cache/pull/1474)