diff --git a/README.md b/README.md
index ce37ef13f..b0f9e9961 100644
--- a/README.md
+++ b/README.md
@@ -10,6 +10,11 @@ The autogenerated OSAL user's guide can be viewed at <https://github.com/nasa/cF
 
 ## Version History
 
+### Development Build: 5.0.0+dev250
+
+- Revision version number now reports 99 during development versions. ES Housekeeping data reports 5.0.99 in the version string.
+- See <https://github.com/nasa/osal/pull/587>
+
 ### Development Build: 5.0.0+dev247
 
 - `OS_SocketOpen()` sets `sock_id` and returns a status when successful.
@@ -19,10 +24,9 @@ The autogenerated OSAL user's guide can be viewed at <https://github.com/nasa/cF
   - The argument names used in stubs match the name in the prototype/documentation so the value can be retrieved by name.
 - Adds back rounding up to PTHREAD_STACK_MIN and also adds rounding up to a system page size. Keeps check for zero stack at the shared level; attempts to create a task with zero stack will fail. Allows internal helper threads to be created with a default minimum stack size.
 - Avoids a possible truncation in snprintf call. No buffer size/truncation warning when building with optimization enabled.
-- Added new macros to `osapi-version` to report baseline and build number 
+- Added new macros to `osapi-version` to report baseline and build number
 - The coverage binaries are now correctly installed for CPU1 and CPU2 as opposed to installed twice to CPU2 but not at all for CPU1.
 - Fixes a typo in ut_assert README and clarifies stub documentation.
-
 - See <https://github.com/nasa/osal/pull/529>
 
 ### Development Build: 5.0.21
@@ -53,7 +57,7 @@ UT assert as a CFE library.
 
 ### Development Build: 5.0.19
 
-- Rename BSPs that can be used on multiple platforms. 
+- Rename BSPs that can be used on multiple platforms.
 `mcp750-vxworks` becomes `generic-vxworks`
 `pc-linux` becomes `generic-linux`
 - New features only, does not change existing behavior.
@@ -73,7 +77,7 @@ UT Hook functions now have the capability to get argument values by name, which
 - Unit tests work on RTEMS without BSP preallocating ramdisks
 - If `OSAL_EXT_SOURCE_DIR` cache variable is set, this location will be checked first for a BSP/OS implementation layer.
 - Implement `OS_GetResourceName()` and `OS_ForEachObjectOfType()`, which are new functions that allow for additional query capabilities. No impact to current behavior as the FSW does not currently use any of these new APIs.
-- A functional test enhancement to `bin-sem-test` which replicates the specific conditions for the observed bug to occur. Deletes the task calling `OS_BinSemTake()` and then attempts to use the semaphore after this. 
+- A functional test enhancement to `bin-sem-test` which replicates the specific conditions for the observed bug to occur. Deletes the task calling `OS_BinSemTake()` and then attempts to use the semaphore after this.
 - Employ a `pthread` "cleanup handler" to handle the situation where a task is canceled during the `pthread_cond_wait()` call. This ensures that the `mutex` is unlocked as part of the cleanup, so other tasks may continue using the semaphore.    
 - Change all initial `mutex` locking to be a finite "timed" wait rather than an infinite wait. In all cases, the condition variable is only held for brief periods of time and should be readily available. If a task blocks for a long time, this considers the mutex "broken" and aborts, thereby avoiding deadlock. This is a "contingency" fix in that if an exception or signal or other unknown/unhandled async event occurs that leaves the mutex permanently locked.
 - Adds the mutex to protect the timer callback `timecb` resource table.
@@ -81,7 +85,7 @@ UT Hook functions now have the capability to get argument values by name, which
 
 ### Development Build: 5.0.17
 
--  `OS_QueueCreate()` will return an error code if the depth parameter is larger than the configured `OS_MAX_QUEUE_DEPTH`. 
+-  `OS_QueueCreate()` will return an error code if the depth parameter is larger than the configured `OS_MAX_QUEUE_DEPTH`.
 - See <https://github.com/nasa/osal/pull/477>
 
 ### Development Build: 5.0.16
@@ -215,4 +219,3 @@ See all open issues and closed to milestones later than this version.
 For best results, submit issues:questions or issues:help wanted requests at <https://github.com/nasa/cFS>.
 
 Official cFS page: <http://cfs.gsfc.nasa.gov>
-
diff --git a/src/os/inc/osapi-version.h b/src/os/inc/osapi-version.h
index 7794b62b6..bfeb926c3 100644
--- a/src/os/inc/osapi-version.h
+++ b/src/os/inc/osapi-version.h
@@ -30,7 +30,7 @@
 /*
  * Development Build Macro Definitions 
  */
-#define OS_BUILD_NUMBER 247 
+#define OS_BUILD_NUMBER 250 
 #define OS_BUILD_BASELINE "v5.0.0+dev"
 
 /*
@@ -38,7 +38,7 @@
  */
 #define OS_MAJOR_VERSION 5 /*!< @brief ONLY APPLY for OFFICIAL releases. Major version number. */
 #define OS_MINOR_VERSION 0 /*!< @brief ONLY APPLY for OFFICIAL releases. Minor version number. */
-#define OS_REVISION      0 /*!< @brief ONLY APPLY for OFFICIAL releases. Revision number. */
+#define OS_REVISION      99/*!< @brief ONLY APPLY for OFFICIAL releases. Revision version number. If set to "99" it indicates a development version.  */
 #define OS_MISSION_REV   0 /*!< @brief ONLY USED by MISSION Implementations. Mission revision */
 
 /*