diff --git a/.changes/cae05a44-3c24-4ba3-9a0b-85aaaa7d9f1f.json b/.changes/cae05a44-3c24-4ba3-9a0b-85aaaa7d9f1f.json
new file mode 100644
index 00000000000..d752dc8fa07
--- /dev/null
+++ b/.changes/cae05a44-3c24-4ba3-9a0b-85aaaa7d9f1f.json
@@ -0,0 +1,8 @@
+{
+    "id": "cae05a44-3c24-4ba3-9a0b-85aaaa7d9f1f",
+    "type": "bugfix",
+    "description": "Correctly route applicationId to requests made by internal clients",
+    "issues": [
+        "https://github.com/aws/aws-sdk-kotlin/issues/1717"
+    ]
+}
\ No newline at end of file
diff --git a/aws-runtime/aws-config/api/aws-config.api b/aws-runtime/aws-config/api/aws-config.api
index ce35a2d9ef5..9b55244e258 100644
--- a/aws-runtime/aws-config/api/aws-config.api
+++ b/aws-runtime/aws-config/api/aws-config.api
@@ -265,6 +265,11 @@ public abstract interface class aws/sdk/kotlin/runtime/config/AwsSdkClientConfig
 	public abstract fun setUseFips (Ljava/lang/Boolean;)V
 }
 
+public final class aws/sdk/kotlin/runtime/config/AwsSdkClientOption {
+	public static final field INSTANCE Laws/sdk/kotlin/runtime/config/AwsSdkClientOption;
+	public final fun getApplicationId ()Laws/smithy/kotlin/runtime/collections/AttributeKey;
+}
+
 public final class aws/sdk/kotlin/runtime/config/AwsSdkSetting {
 	public static final field INSTANCE Laws/sdk/kotlin/runtime/config/AwsSdkSetting;
 	public final fun getAwsAccessKeyId ()Laws/smithy/kotlin/runtime/config/EnvironmentSetting;
diff --git a/aws-runtime/aws-config/common/src/aws/sdk/kotlin/runtime/auth/credentials/SsoCredentialsProvider.kt b/aws-runtime/aws-config/common/src/aws/sdk/kotlin/runtime/auth/credentials/SsoCredentialsProvider.kt
index 3cb4304b5f8..a8f90cbd508 100644
--- a/aws-runtime/aws-config/common/src/aws/sdk/kotlin/runtime/auth/credentials/SsoCredentialsProvider.kt
+++ b/aws-runtime/aws-config/common/src/aws/sdk/kotlin/runtime/auth/credentials/SsoCredentialsProvider.kt
@@ -8,6 +8,7 @@ package aws.sdk.kotlin.runtime.auth.credentials
 import aws.sdk.kotlin.runtime.auth.credentials.internal.credentials
 import aws.sdk.kotlin.runtime.auth.credentials.internal.sso.SsoClient
 import aws.sdk.kotlin.runtime.auth.credentials.internal.sso.getRoleCredentials
+import aws.sdk.kotlin.runtime.config.AwsSdkClientOption
 import aws.sdk.kotlin.runtime.http.interceptors.businessmetrics.AwsBusinessMetric
 import aws.sdk.kotlin.runtime.http.interceptors.businessmetrics.withBusinessMetric
 import aws.smithy.kotlin.runtime.auth.awscredentials.*
@@ -102,6 +103,7 @@ public class SsoCredentialsProvider public constructor(
             httpClient = this@SsoCredentialsProvider.httpClient
             telemetryProvider = telemetry
             logMode = attributes.getOrNull(SdkClientOption.LogMode)
+            applicationId = attributes.getOrNull(AwsSdkClientOption.ApplicationId)
             // FIXME - create an anonymous credential provider to explicitly avoid default chain creation (technically the transform should remove need for sigv4 cred provider since it's all anon auth)
         }
 
diff --git a/aws-runtime/aws-config/common/src/aws/sdk/kotlin/runtime/auth/credentials/StsAssumeRoleCredentialsProvider.kt b/aws-runtime/aws-config/common/src/aws/sdk/kotlin/runtime/auth/credentials/StsAssumeRoleCredentialsProvider.kt
index e84781e95ea..486f5a98465 100644
--- a/aws-runtime/aws-config/common/src/aws/sdk/kotlin/runtime/auth/credentials/StsAssumeRoleCredentialsProvider.kt
+++ b/aws-runtime/aws-config/common/src/aws/sdk/kotlin/runtime/auth/credentials/StsAssumeRoleCredentialsProvider.kt
@@ -12,6 +12,7 @@ import aws.sdk.kotlin.runtime.auth.credentials.internal.sts.assumeRole
 import aws.sdk.kotlin.runtime.auth.credentials.internal.sts.model.PolicyDescriptorType
 import aws.sdk.kotlin.runtime.auth.credentials.internal.sts.model.RegionDisabledException
 import aws.sdk.kotlin.runtime.auth.credentials.internal.sts.model.Tag
+import aws.sdk.kotlin.runtime.config.AwsSdkClientOption
 import aws.sdk.kotlin.runtime.config.AwsSdkSetting
 import aws.sdk.kotlin.runtime.http.interceptors.businessmetrics.AwsBusinessMetric
 import aws.sdk.kotlin.runtime.http.interceptors.businessmetrics.withBusinessMetric
@@ -106,6 +107,7 @@ public class StsAssumeRoleCredentialsProvider(
             httpClient = provider.httpClient
             telemetryProvider = telemetry
             logMode = attributes.getOrNull(SdkClientOption.LogMode)
+            applicationId = attributes.getOrNull(AwsSdkClientOption.ApplicationId)
         }
 
         val resp = try {
diff --git a/aws-runtime/aws-config/common/src/aws/sdk/kotlin/runtime/auth/credentials/StsWebIdentityCredentialsProvider.kt b/aws-runtime/aws-config/common/src/aws/sdk/kotlin/runtime/auth/credentials/StsWebIdentityCredentialsProvider.kt
index 3f5147f1968..b13f3ff2d03 100644
--- a/aws-runtime/aws-config/common/src/aws/sdk/kotlin/runtime/auth/credentials/StsWebIdentityCredentialsProvider.kt
+++ b/aws-runtime/aws-config/common/src/aws/sdk/kotlin/runtime/auth/credentials/StsWebIdentityCredentialsProvider.kt
@@ -10,6 +10,7 @@ import aws.sdk.kotlin.runtime.auth.credentials.internal.credentials
 import aws.sdk.kotlin.runtime.auth.credentials.internal.sts.StsClient
 import aws.sdk.kotlin.runtime.auth.credentials.internal.sts.assumeRoleWithWebIdentity
 import aws.sdk.kotlin.runtime.auth.credentials.internal.sts.model.PolicyDescriptorType
+import aws.sdk.kotlin.runtime.config.AwsSdkClientOption
 import aws.sdk.kotlin.runtime.config.AwsSdkSetting
 import aws.sdk.kotlin.runtime.http.interceptors.businessmetrics.AwsBusinessMetric
 import aws.sdk.kotlin.runtime.http.interceptors.businessmetrics.withBusinessMetric
@@ -122,6 +123,7 @@ public class StsWebIdentityCredentialsProvider(
             // NOTE: credentials provider not needed for this operation
             telemetryProvider = telemetry
             logMode = attributes.getOrNull(SdkClientOption.LogMode)
+            applicationId = attributes.getOrNull(AwsSdkClientOption.ApplicationId)
         }
 
         val resp = try {
diff --git a/aws-runtime/aws-config/common/src/aws/sdk/kotlin/runtime/config/AwsSdkClientOption.kt b/aws-runtime/aws-config/common/src/aws/sdk/kotlin/runtime/config/AwsSdkClientOption.kt
new file mode 100644
index 00000000000..0defe514643
--- /dev/null
+++ b/aws-runtime/aws-config/common/src/aws/sdk/kotlin/runtime/config/AwsSdkClientOption.kt
@@ -0,0 +1,20 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package aws.sdk.kotlin.runtime.config
+
+import aws.smithy.kotlin.runtime.collections.AttributeKey
+
+/**
+ * Common client execution options.
+ * AWS-specific version of [aws.smithy.kotlin.runtime.client.SdkClientOption]
+ */
+public object AwsSdkClientOption {
+    /**
+     * An optional application specific identifier.
+     * When set it will be appended to the User-Agent header of every request in the form of: `app/{applicationId}`.
+     */
+    public val ApplicationId: AttributeKey<String> = AttributeKey("aws.sdk.kotlin#ApplicationId")
+}
diff --git a/codegen/aws-sdk-codegen/src/main/kotlin/aws/sdk/kotlin/codegen/AwsRuntimeTypes.kt b/codegen/aws-sdk-codegen/src/main/kotlin/aws/sdk/kotlin/codegen/AwsRuntimeTypes.kt
index 56364a006b2..f5a7c40846d 100644
--- a/codegen/aws-sdk-codegen/src/main/kotlin/aws/sdk/kotlin/codegen/AwsRuntimeTypes.kt
+++ b/codegen/aws-sdk-codegen/src/main/kotlin/aws/sdk/kotlin/codegen/AwsRuntimeTypes.kt
@@ -38,6 +38,7 @@ object AwsRuntimeTypes {
         val AbstractAwsSdkClientFactory = symbol("AbstractAwsSdkClientFactory", "config")
 
         val AwsSdkClientConfig = symbol("AwsSdkClientConfig", "config")
+        val AwsSdkClientOption = symbol("AwsSdkClientOption", "config")
 
         object Endpoints : RuntimeTypePackage(AwsKotlinDependency.AWS_CONFIG, "config.endpoints") {
             val AccountIdEndpointMode = symbol("AccountIdEndpointMode")
diff --git a/codegen/aws-sdk-codegen/src/main/kotlin/aws/sdk/kotlin/codegen/AwsServiceConfigIntegration.kt b/codegen/aws-sdk-codegen/src/main/kotlin/aws/sdk/kotlin/codegen/AwsServiceConfigIntegration.kt
index 436a6a5aa8e..999bd8f53c3 100644
--- a/codegen/aws-sdk-codegen/src/main/kotlin/aws/sdk/kotlin/codegen/AwsServiceConfigIntegration.kt
+++ b/codegen/aws-sdk-codegen/src/main/kotlin/aws/sdk/kotlin/codegen/AwsServiceConfigIntegration.kt
@@ -5,6 +5,7 @@
 package aws.sdk.kotlin.codegen
 
 import software.amazon.smithy.kotlin.codegen.core.*
+import software.amazon.smithy.kotlin.codegen.integration.AppendingSectionWriter
 import software.amazon.smithy.kotlin.codegen.integration.KotlinIntegration
 import software.amazon.smithy.kotlin.codegen.integration.SectionWriterBinding
 import software.amazon.smithy.kotlin.codegen.lang.KotlinTypes
@@ -12,6 +13,7 @@ import software.amazon.smithy.kotlin.codegen.model.asNullable
 import software.amazon.smithy.kotlin.codegen.model.knowledge.AwsSignatureVersion4
 import software.amazon.smithy.kotlin.codegen.model.nullable
 import software.amazon.smithy.kotlin.codegen.rendering.*
+import software.amazon.smithy.kotlin.codegen.rendering.protocol.HttpProtocolClientGenerator
 import software.amazon.smithy.kotlin.codegen.rendering.util.ConfigProperty
 import software.amazon.smithy.kotlin.codegen.rendering.util.ConfigPropertyType
 import software.amazon.smithy.kotlin.codegen.rendering.util.RuntimeConfigProperty
@@ -173,6 +175,12 @@ class AwsServiceConfigIntegration : KotlinIntegration {
                     writer.getContextValue(ServiceClientGenerator.Sections.CompanionObject.ServiceSymbol),
                 )
             },
+            SectionWriterBinding(
+                HttpProtocolClientGenerator.MergeServiceDefaults,
+                AppendingSectionWriter { writer ->
+                    writer.write("ctx.#T(#T.ApplicationId, config.#L)", RuntimeTypes.Core.Collections.putIfAbsentNotNull, AwsRuntimeTypes.Config.AwsSdkClientOption, UserAgentAppId.propertyName)
+                },
+            ),
         )
 
     override fun additionalServiceConfigProps(ctx: CodegenContext): List<ConfigProperty> = buildList {