diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0686fcdf..691b941a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,23 @@
 # Optimizely C# SDK Changelog
 
+## 4.3.0
+May 4, 2026
+
+### New Features
+
+**Feature Rollout**: Added support for Feature Rollouts, a new experiment type
+combining Targeted Delivery simplicity with A/B test measurement capabilities.
+Feature Rollouts enable progressive rollouts with full impact analytics, metric tracking,
+and confidence intervals.
+See [Feature Rollout docs](https://support.optimizely.com/hc/en-us/articles/45552846481037-Run-Feature-Rollouts-in-Feature-Experimentation) for more information.
+
+- Add Feature Rollout support ([#400](https://github.com/optimizely/csharp-sdk/pull/400))
+- Remove experiment type validation from config parsing ([#402](https://github.com/optimizely/csharp-sdk/pull/402))
+- Source clear removal ([#401](https://github.com/optimizely/csharp-sdk/pull/401))
+- Docs Bash - README update ([#399](https://github.com/optimizely/csharp-sdk/pull/399))
+- Event retry adjustment ([#398](https://github.com/optimizely/csharp-sdk/pull/398))
+- Pipeline update ([#397](https://github.com/optimizely/csharp-sdk/pull/397))
+
 ## 4.2.0
 Nov 13, 2025
 
diff --git a/OptimizelySDK.Net35/Properties/AssemblyInfo.cs b/OptimizelySDK.Net35/Properties/AssemblyInfo.cs
index 77c07883..48144c22 100644
--- a/OptimizelySDK.Net35/Properties/AssemblyInfo.cs
+++ b/OptimizelySDK.Net35/Properties/AssemblyInfo.cs
@@ -37,6 +37,6 @@
 //
 // You can specify all the values or you can default the Build and Revision Numbers 
 // by using the '*' as shown below:
-[assembly: AssemblyVersion("4.2.0.0")]
-[assembly: AssemblyFileVersion("4.2.0.0")]
-[assembly: AssemblyInformationalVersion("4.2.0")] // Used by NuGet.
+[assembly: AssemblyVersion("4.3.0.0")]
+[assembly: AssemblyFileVersion("4.3.0.0")]
+[assembly: AssemblyInformationalVersion("4.3.0")] // Used by NuGet.
diff --git a/OptimizelySDK.Net40/Properties/AssemblyInfo.cs b/OptimizelySDK.Net40/Properties/AssemblyInfo.cs
index 368d2d5f..8daa6c01 100644
--- a/OptimizelySDK.Net40/Properties/AssemblyInfo.cs
+++ b/OptimizelySDK.Net40/Properties/AssemblyInfo.cs
@@ -37,6 +37,6 @@
 //
 // You can specify all the values or you can default the Build and Revision Numbers
 // by using the '*' as shown below:
-[assembly: AssemblyVersion("4.2.0.0")]
-[assembly: AssemblyFileVersion("4.2.0.0")]
-[assembly: AssemblyInformationalVersion("4.2.0")] // Used by NuGet.
+[assembly: AssemblyVersion("4.3.0.0")]
+[assembly: AssemblyFileVersion("4.3.0.0")]
+[assembly: AssemblyInformationalVersion("4.3.0")] // Used by NuGet.
diff --git a/OptimizelySDK.NetStandard16/Properties/AssemblyInfo.cs b/OptimizelySDK.NetStandard16/Properties/AssemblyInfo.cs
index 018b6364..d75ac8d2 100644
--- a/OptimizelySDK.NetStandard16/Properties/AssemblyInfo.cs
+++ b/OptimizelySDK.NetStandard16/Properties/AssemblyInfo.cs
@@ -37,6 +37,6 @@
 //
 // You can specify all the values or you can default the Build and Revision Numbers
 // by using the '*' as shown below:
-[assembly: AssemblyVersion("4.2.0")]
-[assembly: AssemblyFileVersion("4.2.0.0")]
-[assembly: AssemblyInformationalVersion("4.2.0")] // Used by NuGet.
+[assembly: AssemblyVersion("4.3.0")]
+[assembly: AssemblyFileVersion("4.3.0.0")]
+[assembly: AssemblyInformationalVersion("4.3.0")] // Used by NuGet.
diff --git a/OptimizelySDK.NetStandard20/Properties/AssemblyInfo.cs b/OptimizelySDK.NetStandard20/Properties/AssemblyInfo.cs
index 9a9f2211..fc0fa989 100644
--- a/OptimizelySDK.NetStandard20/Properties/AssemblyInfo.cs
+++ b/OptimizelySDK.NetStandard20/Properties/AssemblyInfo.cs
@@ -37,6 +37,6 @@
 //
 // You can specify all the values or you can default the Build and Revision Numbers
 // by using the '*' as shown below:
-[assembly: AssemblyVersion("4.2.0.0")]
-[assembly: AssemblyFileVersion("4.2.0.0")]
-[assembly: AssemblyInformationalVersion("4.2.0")] // Used by NuGet.
+[assembly: AssemblyVersion("4.3.0.0")]
+[assembly: AssemblyFileVersion("4.3.0.0")]
+[assembly: AssemblyInformationalVersion("4.3.0")] // Used by NuGet.
diff --git a/OptimizelySDK/Properties/AssemblyInfo.cs b/OptimizelySDK/Properties/AssemblyInfo.cs
index c06a0d5d..a5c0ee75 100644
--- a/OptimizelySDK/Properties/AssemblyInfo.cs
+++ b/OptimizelySDK/Properties/AssemblyInfo.cs
@@ -41,6 +41,6 @@
 //
 // You can specify all the values or you can default the Build and Revision Numbers 
 // by using the '*' as shown below:
-[assembly: AssemblyVersion("4.2.0.0")]
-[assembly: AssemblyFileVersion("4.2.0.0")]
-[assembly: AssemblyInformationalVersion("4.2.0")] // Used by NuGet.
+[assembly: AssemblyVersion("4.3.0.0")]
+[assembly: AssemblyFileVersion("4.3.0.0")]
+[assembly: AssemblyInformationalVersion("4.3.0")] // Used by NuGet.