diff --git a/README.md b/README.md
index 04bc286e5..06a364a99 100644
--- a/README.md
+++ b/README.md
@@ -11,6 +11,14 @@ The autogenerated OSAL user's guide can be viewed at <https://github.com/nasa/cF
 
 ## Version History
 
+### Development Build: v5.1.0-rc1+dev586
+
+- Add UtAssert_MIR macro
+- Add generic asserts from CFE coverage testing 
+- Add osapi-shell-stubs.c to OSAL stub library
+- See <https://github.com/nasa/osal/pull/1126> and <https://github.com/nasa/cFS/pull/328>
+
+
 ### Development Build: v5.1.0-rc1+dev578
 
 - Add unit test branch coverage
diff --git a/src/os/inc/osapi-version.h b/src/os/inc/osapi-version.h
index e37830adb..1cecb3e75 100644
--- a/src/os/inc/osapi-version.h
+++ b/src/os/inc/osapi-version.h
@@ -36,7 +36,7 @@
 /*
  * Development Build Macro Definitions
  */
-#define OS_BUILD_NUMBER   578
+#define OS_BUILD_NUMBER   586
 #define OS_BUILD_BASELINE "v5.1.0-rc1"
 
 /*