diff --git a/CHANGELOG.md b/CHANGELOG.md
index 98df8f8ab1f..8d806c064ae 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,17 @@
 # Changelog
 
+### [6.12.4](https://www.github.com/googleapis/java-spanner/compare/v6.12.3...v6.12.4) (2021-09-16)
+
+
+### Bug Fixes
+
+* do not serialize unnecessary fields ([#1426](https://www.github.com/googleapis/java-spanner/issues/1426)) ([29209f8](https://www.github.com/googleapis/java-spanner/commit/29209f83d10fa01b5566da66259da95dd60abca0))
+
+
+### Dependencies
+
+* update dependency com.google.cloud:google-cloud-monitoring to v3.0.5 ([#1431](https://www.github.com/googleapis/java-spanner/issues/1431)) ([32eee0a](https://www.github.com/googleapis/java-spanner/commit/32eee0aa14f0b276673dca7a65e011a509e96453))
+
 ### [6.12.3](https://www.github.com/googleapis/java-spanner/compare/v6.12.2...v6.12.3) (2021-09-15)
 
 
diff --git a/google-cloud-spanner-bom/pom.xml b/google-cloud-spanner-bom/pom.xml
index 390672c2391..5bbd16686ac 100644
--- a/google-cloud-spanner-bom/pom.xml
+++ b/google-cloud-spanner-bom/pom.xml
@@ -3,7 +3,7 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-spanner-bom</artifactId>
-  <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:google-cloud-spanner:current} -->
+  <version>6.12.4</version><!-- {x-version-update:google-cloud-spanner:current} -->
   <packaging>pom</packaging>
   <parent>
     <groupId>com.google.cloud</groupId>
@@ -54,43 +54,43 @@
       <dependency>
         <groupId>com.google.api.grpc</groupId>
         <artifactId>proto-google-cloud-spanner-admin-instance-v1</artifactId>
-        <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:proto-google-cloud-spanner-admin-instance-v1:current} -->
+        <version>6.12.4</version><!-- {x-version-update:proto-google-cloud-spanner-admin-instance-v1:current} -->
       </dependency>
       <dependency>
         <groupId>com.google.api.grpc</groupId>
         <artifactId>grpc-google-cloud-spanner-v1</artifactId>
-        <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:grpc-google-cloud-spanner-v1:current} -->
+        <version>6.12.4</version><!-- {x-version-update:grpc-google-cloud-spanner-v1:current} -->
       </dependency>
       <dependency>
         <groupId>com.google.api.grpc</groupId>
         <artifactId>proto-google-cloud-spanner-v1</artifactId>
-        <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:proto-google-cloud-spanner-v1:current} -->
+        <version>6.12.4</version><!-- {x-version-update:proto-google-cloud-spanner-v1:current} -->
       </dependency>
       <dependency>
         <groupId>com.google.api.grpc</groupId>
         <artifactId>proto-google-cloud-spanner-admin-database-v1</artifactId>
-        <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:proto-google-cloud-spanner-admin-database-v1:current} -->
+        <version>6.12.4</version><!-- {x-version-update:proto-google-cloud-spanner-admin-database-v1:current} -->
       </dependency>
       <dependency>
         <groupId>com.google.cloud</groupId>
         <artifactId>google-cloud-spanner</artifactId>
-        <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:google-cloud-spanner:current} -->
+        <version>6.12.4</version><!-- {x-version-update:google-cloud-spanner:current} -->
       </dependency>
       <dependency>
         <groupId>com.google.cloud</groupId>
         <artifactId>google-cloud-spanner</artifactId>
         <type>test-jar</type>
-        <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:google-cloud-spanner:current} -->
+        <version>6.12.4</version><!-- {x-version-update:google-cloud-spanner:current} -->
       </dependency>
       <dependency>
         <groupId>com.google.api.grpc</groupId>
         <artifactId>grpc-google-cloud-spanner-admin-instance-v1</artifactId>
-        <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:grpc-google-cloud-spanner-admin-instance-v1:current} -->
+        <version>6.12.4</version><!-- {x-version-update:grpc-google-cloud-spanner-admin-instance-v1:current} -->
       </dependency>
       <dependency>
         <groupId>com.google.api.grpc</groupId>
         <artifactId>grpc-google-cloud-spanner-admin-database-v1</artifactId>
-        <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:grpc-google-cloud-spanner-admin-database-v1:current} -->
+        <version>6.12.4</version><!-- {x-version-update:grpc-google-cloud-spanner-admin-database-v1:current} -->
       </dependency>
     </dependencies>
   </dependencyManagement>
diff --git a/google-cloud-spanner/pom.xml b/google-cloud-spanner/pom.xml
index 1f726e9d147..051d41753d1 100644
--- a/google-cloud-spanner/pom.xml
+++ b/google-cloud-spanner/pom.xml
@@ -3,7 +3,7 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-spanner</artifactId>
-  <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:google-cloud-spanner:current} -->
+  <version>6.12.4</version><!-- {x-version-update:google-cloud-spanner:current} -->
   <packaging>jar</packaging>
   <name>Google Cloud Spanner</name>
   <url>https://github.com/googleapis/java-spanner</url>
@@ -11,7 +11,7 @@
   <parent>
     <groupId>com.google.cloud</groupId>
     <artifactId>google-cloud-spanner-parent</artifactId>
-    <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:google-cloud-spanner:current} -->
+    <version>6.12.4</version><!-- {x-version-update:google-cloud-spanner:current} -->
   </parent>
   <properties>
     <site.installationModule>google-cloud-spanner</site.installationModule>
diff --git a/grpc-google-cloud-spanner-admin-database-v1/pom.xml b/grpc-google-cloud-spanner-admin-database-v1/pom.xml
index a7ff6677134..1734cf1ea1c 100644
--- a/grpc-google-cloud-spanner-admin-database-v1/pom.xml
+++ b/grpc-google-cloud-spanner-admin-database-v1/pom.xml
@@ -4,13 +4,13 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>com.google.api.grpc</groupId>
   <artifactId>grpc-google-cloud-spanner-admin-database-v1</artifactId>
-  <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:grpc-google-cloud-spanner-admin-database-v1:current} -->
+  <version>6.12.4</version><!-- {x-version-update:grpc-google-cloud-spanner-admin-database-v1:current} -->
   <name>grpc-google-cloud-spanner-admin-database-v1</name>
   <description>GRPC library for grpc-google-cloud-spanner-admin-database-v1</description>
   <parent>
     <groupId>com.google.cloud</groupId>
     <artifactId>google-cloud-spanner-parent</artifactId>
-    <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:google-cloud-spanner:current} -->
+    <version>6.12.4</version><!-- {x-version-update:google-cloud-spanner:current} -->
   </parent>
   <dependencies>
     <dependency>
diff --git a/grpc-google-cloud-spanner-admin-instance-v1/pom.xml b/grpc-google-cloud-spanner-admin-instance-v1/pom.xml
index f12a9375342..745e838f99f 100644
--- a/grpc-google-cloud-spanner-admin-instance-v1/pom.xml
+++ b/grpc-google-cloud-spanner-admin-instance-v1/pom.xml
@@ -4,13 +4,13 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>com.google.api.grpc</groupId>
   <artifactId>grpc-google-cloud-spanner-admin-instance-v1</artifactId>
-  <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:grpc-google-cloud-spanner-admin-instance-v1:current} -->
+  <version>6.12.4</version><!-- {x-version-update:grpc-google-cloud-spanner-admin-instance-v1:current} -->
   <name>grpc-google-cloud-spanner-admin-instance-v1</name>
   <description>GRPC library for grpc-google-cloud-spanner-admin-instance-v1</description>
   <parent>
     <groupId>com.google.cloud</groupId>
     <artifactId>google-cloud-spanner-parent</artifactId>
-    <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:google-cloud-spanner:current} -->
+    <version>6.12.4</version><!-- {x-version-update:google-cloud-spanner:current} -->
   </parent>
   <dependencies>
     <dependency>
diff --git a/grpc-google-cloud-spanner-v1/pom.xml b/grpc-google-cloud-spanner-v1/pom.xml
index a7a1be47ce6..9cd116fb8d0 100644
--- a/grpc-google-cloud-spanner-v1/pom.xml
+++ b/grpc-google-cloud-spanner-v1/pom.xml
@@ -4,13 +4,13 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>com.google.api.grpc</groupId>
   <artifactId>grpc-google-cloud-spanner-v1</artifactId>
-  <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:grpc-google-cloud-spanner-v1:current} -->
+  <version>6.12.4</version><!-- {x-version-update:grpc-google-cloud-spanner-v1:current} -->
   <name>grpc-google-cloud-spanner-v1</name>
   <description>GRPC library for grpc-google-cloud-spanner-v1</description>
   <parent>
     <groupId>com.google.cloud</groupId>
     <artifactId>google-cloud-spanner-parent</artifactId>
-    <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:google-cloud-spanner:current} -->
+    <version>6.12.4</version><!-- {x-version-update:google-cloud-spanner:current} -->
   </parent>
   <dependencies>
     <dependency>
diff --git a/pom.xml b/pom.xml
index 10d2a888ef7..e6744e6b68f 100644
--- a/pom.xml
+++ b/pom.xml
@@ -4,7 +4,7 @@
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-spanner-parent</artifactId>
   <packaging>pom</packaging>
-  <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:google-cloud-spanner:current} -->
+  <version>6.12.4</version><!-- {x-version-update:google-cloud-spanner:current} -->
   <name>Google Cloud Spanner Parent</name>
   <url>https://github.com/googleapis/java-spanner</url>
   <description>
@@ -62,37 +62,37 @@
       <dependency>
         <groupId>com.google.api.grpc</groupId>
         <artifactId>proto-google-cloud-spanner-admin-instance-v1</artifactId>
-        <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:proto-google-cloud-spanner-admin-instance-v1:current} -->
+        <version>6.12.4</version><!-- {x-version-update:proto-google-cloud-spanner-admin-instance-v1:current} -->
       </dependency>
       <dependency>
         <groupId>com.google.api.grpc</groupId>
         <artifactId>proto-google-cloud-spanner-v1</artifactId>
-        <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:proto-google-cloud-spanner-v1:current} -->
+        <version>6.12.4</version><!-- {x-version-update:proto-google-cloud-spanner-v1:current} -->
       </dependency>
       <dependency>
         <groupId>com.google.api.grpc</groupId>
         <artifactId>proto-google-cloud-spanner-admin-database-v1</artifactId>
-        <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:proto-google-cloud-spanner-admin-database-v1:current} -->
+        <version>6.12.4</version><!-- {x-version-update:proto-google-cloud-spanner-admin-database-v1:current} -->
       </dependency>
       <dependency>
         <groupId>com.google.api.grpc</groupId>
         <artifactId>grpc-google-cloud-spanner-v1</artifactId>
-        <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:grpc-google-cloud-spanner-v1:current} -->
+        <version>6.12.4</version><!-- {x-version-update:grpc-google-cloud-spanner-v1:current} -->
       </dependency>
       <dependency>
         <groupId>com.google.api.grpc</groupId>
         <artifactId>grpc-google-cloud-spanner-admin-instance-v1</artifactId>
-        <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:grpc-google-cloud-spanner-admin-instance-v1:current} -->
+        <version>6.12.4</version><!-- {x-version-update:grpc-google-cloud-spanner-admin-instance-v1:current} -->
       </dependency>
       <dependency>
         <groupId>com.google.api.grpc</groupId>
         <artifactId>grpc-google-cloud-spanner-admin-database-v1</artifactId>
-        <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:grpc-google-cloud-spanner-admin-database-v1:current} -->
+        <version>6.12.4</version><!-- {x-version-update:grpc-google-cloud-spanner-admin-database-v1:current} -->
       </dependency>
       <dependency>
         <groupId>com.google.cloud</groupId>
         <artifactId>google-cloud-spanner</artifactId>
-        <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:google-cloud-spanner:current} -->
+        <version>6.12.4</version><!-- {x-version-update:google-cloud-spanner:current} -->
       </dependency>
 
       <dependency>
diff --git a/proto-google-cloud-spanner-admin-database-v1/pom.xml b/proto-google-cloud-spanner-admin-database-v1/pom.xml
index d8fb2d6312b..a740926be75 100644
--- a/proto-google-cloud-spanner-admin-database-v1/pom.xml
+++ b/proto-google-cloud-spanner-admin-database-v1/pom.xml
@@ -4,13 +4,13 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>com.google.api.grpc</groupId>
   <artifactId>proto-google-cloud-spanner-admin-database-v1</artifactId>
-  <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:proto-google-cloud-spanner-admin-database-v1:current} -->
+  <version>6.12.4</version><!-- {x-version-update:proto-google-cloud-spanner-admin-database-v1:current} -->
   <name>proto-google-cloud-spanner-admin-database-v1</name>
   <description>PROTO library for proto-google-cloud-spanner-admin-database-v1</description>
   <parent>
     <groupId>com.google.cloud</groupId>
     <artifactId>google-cloud-spanner-parent</artifactId>
-    <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:google-cloud-spanner:current} -->
+    <version>6.12.4</version><!-- {x-version-update:google-cloud-spanner:current} -->
   </parent>
   <dependencies>
     <dependency>
diff --git a/proto-google-cloud-spanner-admin-instance-v1/pom.xml b/proto-google-cloud-spanner-admin-instance-v1/pom.xml
index 5fe284b9bd8..6b761b088a4 100644
--- a/proto-google-cloud-spanner-admin-instance-v1/pom.xml
+++ b/proto-google-cloud-spanner-admin-instance-v1/pom.xml
@@ -4,13 +4,13 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>com.google.api.grpc</groupId>
   <artifactId>proto-google-cloud-spanner-admin-instance-v1</artifactId>
-  <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:proto-google-cloud-spanner-admin-instance-v1:current} -->
+  <version>6.12.4</version><!-- {x-version-update:proto-google-cloud-spanner-admin-instance-v1:current} -->
   <name>proto-google-cloud-spanner-admin-instance-v1</name>
   <description>PROTO library for proto-google-cloud-spanner-admin-instance-v1</description>
   <parent>
     <groupId>com.google.cloud</groupId>
     <artifactId>google-cloud-spanner-parent</artifactId>
-    <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:google-cloud-spanner:current} -->
+    <version>6.12.4</version><!-- {x-version-update:google-cloud-spanner:current} -->
   </parent>
   <dependencies>
     <dependency>
diff --git a/proto-google-cloud-spanner-v1/pom.xml b/proto-google-cloud-spanner-v1/pom.xml
index 49b7f582ad4..d826f9a165f 100644
--- a/proto-google-cloud-spanner-v1/pom.xml
+++ b/proto-google-cloud-spanner-v1/pom.xml
@@ -4,13 +4,13 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>com.google.api.grpc</groupId>
   <artifactId>proto-google-cloud-spanner-v1</artifactId>
-  <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:proto-google-cloud-spanner-v1:current} -->
+  <version>6.12.4</version><!-- {x-version-update:proto-google-cloud-spanner-v1:current} -->
   <name>proto-google-cloud-spanner-v1</name>
   <description>PROTO library for proto-google-cloud-spanner-v1</description>
   <parent>
     <groupId>com.google.cloud</groupId>
     <artifactId>google-cloud-spanner-parent</artifactId>
-    <version>6.12.4-SNAPSHOT</version><!-- {x-version-update:google-cloud-spanner:current} -->
+    <version>6.12.4</version><!-- {x-version-update:google-cloud-spanner:current} -->
   </parent>
   <dependencies>
     <dependency>
diff --git a/samples/snapshot/pom.xml b/samples/snapshot/pom.xml
index 23c020acedd..58593287ea9 100644
--- a/samples/snapshot/pom.xml
+++ b/samples/snapshot/pom.xml
@@ -31,7 +31,7 @@
     <dependency>
       <groupId>com.google.cloud</groupId>
       <artifactId>google-cloud-spanner</artifactId>
-      <version>6.12.4-SNAPSHOT</version>
+      <version>6.12.4</version>
     </dependency>
     <!-- {x-version-update-end} -->
     
diff --git a/versions.txt b/versions.txt
index b3da96528cf..0634862c4b8 100644
--- a/versions.txt
+++ b/versions.txt
@@ -1,10 +1,10 @@
 # Format:
 # module:released-version:current-version
 
-proto-google-cloud-spanner-admin-instance-v1:6.12.3:6.12.4-SNAPSHOT
-proto-google-cloud-spanner-v1:6.12.3:6.12.4-SNAPSHOT
-proto-google-cloud-spanner-admin-database-v1:6.12.3:6.12.4-SNAPSHOT
-grpc-google-cloud-spanner-v1:6.12.3:6.12.4-SNAPSHOT
-grpc-google-cloud-spanner-admin-instance-v1:6.12.3:6.12.4-SNAPSHOT
-grpc-google-cloud-spanner-admin-database-v1:6.12.3:6.12.4-SNAPSHOT
-google-cloud-spanner:6.12.3:6.12.4-SNAPSHOT
\ No newline at end of file
+proto-google-cloud-spanner-admin-instance-v1:6.12.4:6.12.4
+proto-google-cloud-spanner-v1:6.12.4:6.12.4
+proto-google-cloud-spanner-admin-database-v1:6.12.4:6.12.4
+grpc-google-cloud-spanner-v1:6.12.4:6.12.4
+grpc-google-cloud-spanner-admin-instance-v1:6.12.4:6.12.4
+grpc-google-cloud-spanner-admin-database-v1:6.12.4:6.12.4
+google-cloud-spanner:6.12.4:6.12.4
\ No newline at end of file