diff --git a/README.md b/README.md
index 5f86faab2d..f9823dbb6e 100644
--- a/README.md
+++ b/README.md
@@ -96,6 +96,11 @@ Silicon Labs:
 * [EFM32 Giant Gecko] (https://developer.mbed.org/platforms/EFM32-Giant-Gecko/) (Cortex-M3)
 * [EFM32 Wonder Gecko] (https://developer.mbed.org/platforms/EFM32-Wonder-Gecko/) (Cortex-M4)
 
+Atmel:
+* [SAM R21 XPRO] (https://developer.mbed.org/platforms/SAMR21-XPRO/) (Cortex-M0+)
+* [SAM L21 XPRO B] (https://developer.mbed.org/platforms/SAML21-XPRO/) (Cortex-M0+)
+* [SAM D21 XPRO] (https://developer.mbed.org/platforms/SAMD21-XPRO/) (Cortex-M0+)
+* [SAM W25 XPRO] (https://developer.mbed.org/platforms/SAMW25-XPRO/) (Cortex-M0+)
 
 Supported Toolchains and IDEs
 -----------------------------
diff --git a/workspace_tools/build_release.py b/workspace_tools/build_release.py
index 660b431e82..44b5fe1f1d 100644
--- a/workspace_tools/build_release.py
+++ b/workspace_tools/build_release.py
@@ -129,6 +129,11 @@ OFFICIAL_MBED_LIBRARY_BUILD = (
     ('WIZWIKI_W7500',   ('ARM', 'uARM')),
     ('WIZWIKI_W7500P',('ARM', 'uARM')),
     ('WIZWIKI_W7500ECO',('ARM', 'uARM')),
+
+    ('SAMR21G18A',('ARM', 'uARM', 'GCC_ARM')),
+    ('SAMD21J18A',('ARM', 'uARM', 'GCC_ARM')),
+    ('SAMD21G18A',('ARM', 'uARM', 'GCC_ARM')),
+
 )