diff --git a/src/OpenTelemetry.Instrumentation.AWS/.publicApi/PublicAPI.Unshipped.txt b/src/OpenTelemetry.Instrumentation.AWS/.publicApi/PublicAPI.Unshipped.txt
index d9f3466a01..1d865f3be0 100644
--- a/src/OpenTelemetry.Instrumentation.AWS/.publicApi/PublicAPI.Unshipped.txt
+++ b/src/OpenTelemetry.Instrumentation.AWS/.publicApi/PublicAPI.Unshipped.txt
@@ -1,6 +1,5 @@
 #nullable enable
 OpenTelemetry.Instrumentation.AWS.SemanticConventionVersion
-OpenTelemetry.Instrumentation.AWS.SemanticConventionVersion.Legacy = -1 -> OpenTelemetry.Instrumentation.AWS.SemanticConventionVersion
 OpenTelemetry.Instrumentation.AWS.SemanticConventionVersion.Latest = 0 -> OpenTelemetry.Instrumentation.AWS.SemanticConventionVersion
 OpenTelemetry.Instrumentation.AWS.SemanticConventionVersion.V1_29_0 = 2 -> OpenTelemetry.Instrumentation.AWS.SemanticConventionVersion
 OpenTelemetry.Instrumentation.AWS.SemanticConventionVersion.V1_28_0 = 1 -> OpenTelemetry.Instrumentation.AWS.SemanticConventionVersion
diff --git a/src/OpenTelemetry.Instrumentation.AWS/CHANGELOG.md b/src/OpenTelemetry.Instrumentation.AWS/CHANGELOG.md
index 11d55af4be..8f39c5a0fa 100644
--- a/src/OpenTelemetry.Instrumentation.AWS/CHANGELOG.md
+++ b/src/OpenTelemetry.Instrumentation.AWS/CHANGELOG.md
@@ -2,6 +2,9 @@
 
 ## Unreleased
 
+* BREAKING: Change default Semantic Convention to 1.28
+* BREAKING: Remove option to use Legacy semantic conventions (the old default)
+
 ## 1.10.0-beta.3
 
 Released 2024-Dec-20
diff --git a/src/OpenTelemetry.Instrumentation.AWSLambda/.publicApi/PublicAPI.Unshipped.txt b/src/OpenTelemetry.Instrumentation.AWSLambda/.publicApi/PublicAPI.Unshipped.txt
index 7afa5bd534..b71913f746 100644
--- a/src/OpenTelemetry.Instrumentation.AWSLambda/.publicApi/PublicAPI.Unshipped.txt
+++ b/src/OpenTelemetry.Instrumentation.AWSLambda/.publicApi/PublicAPI.Unshipped.txt
@@ -1,5 +1,4 @@
 #nullable enable
-OpenTelemetry.Instrumentation.AWSLambda.SemanticConventionVersion.Legacy = -1 -> OpenTelemetry.Instrumentation.AWSLambda.SemanticConventionVersion
 OpenTelemetry.Instrumentation.AWSLambda.SemanticConventionVersion
 OpenTelemetry.Instrumentation.AWSLambda.SemanticConventionVersion.Latest = 0 -> OpenTelemetry.Instrumentation.AWSLambda.SemanticConventionVersion
 OpenTelemetry.Instrumentation.AWSLambda.SemanticConventionVersion.V1_29_0 = 2 -> OpenTelemetry.Instrumentation.AWSLambda.SemanticConventionVersion
diff --git a/src/OpenTelemetry.Instrumentation.AWSLambda/CHANGELOG.md b/src/OpenTelemetry.Instrumentation.AWSLambda/CHANGELOG.md
index ea4df13ce6..817c6b06af 100644
--- a/src/OpenTelemetry.Instrumentation.AWSLambda/CHANGELOG.md
+++ b/src/OpenTelemetry.Instrumentation.AWSLambda/CHANGELOG.md
@@ -2,6 +2,9 @@
 
 ## Unreleased
 
+* BREAKING: Change default Semantic Convention to 1.28
+* BREAKING: Remove option to use Legacy semantic conventions (the old default)
+
 ## 1.10.0-beta.3
 
 Released 2024-Dec-20
diff --git a/src/OpenTelemetry.Resources.AWS/.publicApi/PublicAPI.Unshipped.txt b/src/OpenTelemetry.Resources.AWS/.publicApi/PublicAPI.Unshipped.txt
index 34d384331a..958bfbb929 100644
--- a/src/OpenTelemetry.Resources.AWS/.publicApi/PublicAPI.Unshipped.txt
+++ b/src/OpenTelemetry.Resources.AWS/.publicApi/PublicAPI.Unshipped.txt
@@ -1,5 +1,4 @@
 OpenTelemetry.Resources.AWS.SemanticConventionVersion
-OpenTelemetry.Resources.AWS.SemanticConventionVersion.Legacy = -1 -> OpenTelemetry.Resources.AWS.SemanticConventionVersion
 OpenTelemetry.Resources.AWS.SemanticConventionVersion.Latest = 0 -> OpenTelemetry.Resources.AWS.SemanticConventionVersion
 OpenTelemetry.Resources.AWS.SemanticConventionVersion.V1_29_0 = 2 -> OpenTelemetry.Resources.AWS.SemanticConventionVersion
 OpenTelemetry.Resources.AWS.SemanticConventionVersion.V1_28_0 = 1 -> OpenTelemetry.Resources.AWS.SemanticConventionVersion
diff --git a/src/OpenTelemetry.Resources.AWS/CHANGELOG.md b/src/OpenTelemetry.Resources.AWS/CHANGELOG.md
index dc8f22ca8f..d592cf945b 100644
--- a/src/OpenTelemetry.Resources.AWS/CHANGELOG.md
+++ b/src/OpenTelemetry.Resources.AWS/CHANGELOG.md
@@ -2,6 +2,9 @@
 
 ## Unreleased
 
+* BREAKING: Change default Semantic Convention to 1.28
+* BREAKING: Remove option to use Legacy semantic conventions (the old default)
+
 ## 1.10.0-beta.1
 
 Released 2024-Dec-20
diff --git a/src/Shared/AWS/AWSSemanticConventions.Legacy.cs b/src/Shared/AWS/AWSSemanticConventions.Legacy.cs
index e391632c2b..275fe38f2a 100644
--- a/src/Shared/AWS/AWSSemanticConventions.Legacy.cs
+++ b/src/Shared/AWS/AWSSemanticConventions.Legacy.cs
@@ -20,7 +20,7 @@ internal partial class AWSSemanticConventions
     /// <remarks>
     /// Future version specific convention classes will only need to define new or changed attributes.
     /// </remarks>
-    private class AWSSemanticConventionsLegacy : AWSSemanticConventionsBase
+    private abstract class AWSSemanticConventionsLegacy : AWSSemanticConventionsBase
     {
         // CLOUD Attributes
         public override string AttributeCloudAccountID => "cloud.account.id";
diff --git a/src/Shared/AWS/AWSSemanticConventions.cs b/src/Shared/AWS/AWSSemanticConventions.cs
index 6c843b1db8..c6c771dc99 100644
--- a/src/Shared/AWS/AWSSemanticConventions.cs
+++ b/src/Shared/AWS/AWSSemanticConventions.cs
@@ -19,9 +19,6 @@
 #pragma warning disable SA1201
 #pragma warning disable SA1623
 
-// disable obsolete warning - remove in RC
-#pragma warning disable CS0618
-
 namespace OpenTelemetry.AWS;
 
 /// <summary>
@@ -69,10 +66,7 @@ internal partial class AWSSemanticConventions
     /// Per SemanticConventionVersion, default should stay as
     /// <see cref="SemanticConventionVersion.V1_28_0"/> until next major version bump.
     /// </remarks>
-    internal const SemanticConventionVersion DefaultSemanticConventionVersion = SemanticConventionVersion.Legacy;
-
-    // RC Release: change to
-    //SemanticConventionVersion.V1_28_0;
+    internal const SemanticConventionVersion DefaultSemanticConventionVersion = SemanticConventionVersion.V1_28_0;
 
     private readonly SemanticConventionVersion semanticConventionVersion;
 
@@ -494,9 +488,6 @@ private AWSSemanticConventionsBase GetSemanticConventionVersion()
             case SemanticConventionVersion.V1_28_0:
                 return new AWSSemanticConventions_V1_28_0();
 
-            case SemanticConventionVersion.Legacy:
-                return new AWSSemanticConventionsLegacy();
-
             default:
                 throw new InvalidEnumArgumentException(
                     argumentName: nameof(SemanticConventionVersion),
diff --git a/src/Shared/AWS/SemanticConventionVersion.cs b/src/Shared/AWS/SemanticConventionVersion.cs
index e00e600699..53c6156878 100644
--- a/src/Shared/AWS/SemanticConventionVersion.cs
+++ b/src/Shared/AWS/SemanticConventionVersion.cs
@@ -73,18 +73,6 @@ public enum SemanticConventionVersion
     /// </summary>
     Latest = 0,
 
-    /// <summary>
-    /// Represents the mixture of Semantic Conventions used in OpenTelemetry.*.AWS libraries
-    /// in 1.10.0-beta.x.
-    /// <para />
-    /// This allows users to upgrade to the latest beta nuget package without experiencing a change in
-    /// Semantic Convention output.  Then there is an opportunity for users to trial <see cref="V1_28_0"/>.
-    /// <para />
-    /// This option will be REMOVED in the next Release Candidate.
-    /// </summary>
-    [Obsolete("This will be removed in the 1.10.0-RC", error: false)]
-    Legacy = -1,
-
     /// <summary>
     /// Pin to the specific state of all Semantic Conventions as of the 1.28.0
     /// release. See: