diff --git a/clients/client-cloudfront-keyvaluestore/src/auth/httpAuthSchemeProvider.ts b/clients/client-cloudfront-keyvaluestore/src/auth/httpAuthSchemeProvider.ts
index e7553783a0a6..d7a607de4c95 100644
--- a/clients/client-cloudfront-keyvaluestore/src/auth/httpAuthSchemeProvider.ts
+++ b/clients/client-cloudfront-keyvaluestore/src/auth/httpAuthSchemeProvider.ts
@@ -1,8 +1,12 @@
 // smithy-typescript generated code
 import {
+  AwsSdkSigV4AAuthInputConfig,
+  AwsSdkSigV4AAuthResolvedConfig,
+  AwsSdkSigV4APreviouslyResolved,
   AwsSdkSigV4AuthInputConfig,
   AwsSdkSigV4AuthResolvedConfig,
   AwsSdkSigV4PreviouslyResolved,
+  resolveAwsSdkSigV4AConfig,
   resolveAwsSdkSigV4Config,
 } from "@aws-sdk/core";
 import { signatureV4CrtContainer } from "@aws-sdk/signature-v4-multi-region";
@@ -297,7 +301,7 @@ export const defaultCloudFrontKeyValueStoreHttpAuthSchemeProvider: CloudFrontKey
 /**
  * @internal
  */
-export interface HttpAuthSchemeInputConfig extends AwsSdkSigV4AuthInputConfig {
+export interface HttpAuthSchemeInputConfig extends AwsSdkSigV4AuthInputConfig, AwsSdkSigV4AAuthInputConfig {
   /**
    * Configuration of HttpAuthSchemes for a client which provides default identity providers and signers per auth scheme.
    * @internal
@@ -314,7 +318,7 @@ export interface HttpAuthSchemeInputConfig extends AwsSdkSigV4AuthInputConfig {
 /**
  * @internal
  */
-export interface HttpAuthSchemeResolvedConfig extends AwsSdkSigV4AuthResolvedConfig {
+export interface HttpAuthSchemeResolvedConfig extends AwsSdkSigV4AuthResolvedConfig, AwsSdkSigV4AAuthResolvedConfig {
   /**
    * Configuration of HttpAuthSchemes for a client which provides default identity providers and signers per auth scheme.
    * @internal
@@ -332,10 +336,11 @@ export interface HttpAuthSchemeResolvedConfig extends AwsSdkSigV4AuthResolvedCon
  * @internal
  */
 export const resolveHttpAuthSchemeConfig = <T>(
-  config: T & HttpAuthSchemeInputConfig & AwsSdkSigV4PreviouslyResolved
+  config: T & HttpAuthSchemeInputConfig & AwsSdkSigV4PreviouslyResolved & AwsSdkSigV4APreviouslyResolved
 ): T & HttpAuthSchemeResolvedConfig => {
   const config_0 = resolveAwsSdkSigV4Config(config);
+  const config_1 = resolveAwsSdkSigV4AConfig(config_0);
   return {
-    ...config_0,
+    ...config_1,
   } as T & HttpAuthSchemeResolvedConfig;
 };
diff --git a/clients/client-cloudfront-keyvaluestore/src/runtimeConfig.ts b/clients/client-cloudfront-keyvaluestore/src/runtimeConfig.ts
index 55c9c128ec53..3334debf0a6a 100644
--- a/clients/client-cloudfront-keyvaluestore/src/runtimeConfig.ts
+++ b/clients/client-cloudfront-keyvaluestore/src/runtimeConfig.ts
@@ -2,7 +2,7 @@
 // @ts-ignore: package.json will be imported from dist folders
 import packageInfo from "../package.json"; // eslint-disable-line
 
-import { emitWarningIfUnsupportedVersion as awsCheckVersion } from "@aws-sdk/core";
+import { NODE_SIGV4A_CONFIG_OPTIONS, emitWarningIfUnsupportedVersion as awsCheckVersion } from "@aws-sdk/core";
 import { defaultProvider as credentialDefaultProvider } from "@aws-sdk/credential-provider-node";
 import { defaultUserAgent } from "@aws-sdk/util-user-agent-node";
 import {
@@ -52,6 +52,7 @@ export const getRuntimeConfig = (config: CloudFrontKeyValueStoreClientConfig) =>
         default: async () => (await defaultConfigProvider()).retryMode || DEFAULT_RETRY_MODE,
       }),
     sha256: config?.sha256 ?? Hash.bind(null, "sha256"),
+    sigv4aSigningRegionSet: config?.sigv4aSigningRegionSet ?? loadNodeConfig(NODE_SIGV4A_CONFIG_OPTIONS),
     streamCollector: config?.streamCollector ?? streamCollector,
     useDualstackEndpoint: config?.useDualstackEndpoint ?? loadNodeConfig(NODE_USE_DUALSTACK_ENDPOINT_CONFIG_OPTIONS),
     useFipsEndpoint: config?.useFipsEndpoint ?? loadNodeConfig(NODE_USE_FIPS_ENDPOINT_CONFIG_OPTIONS),
diff --git a/clients/client-eventbridge/src/auth/httpAuthSchemeProvider.ts b/clients/client-eventbridge/src/auth/httpAuthSchemeProvider.ts
index 91efc1182208..2cd67398e03f 100644
--- a/clients/client-eventbridge/src/auth/httpAuthSchemeProvider.ts
+++ b/clients/client-eventbridge/src/auth/httpAuthSchemeProvider.ts
@@ -1,8 +1,12 @@
 // smithy-typescript generated code
 import {
+  AwsSdkSigV4AAuthInputConfig,
+  AwsSdkSigV4AAuthResolvedConfig,
+  AwsSdkSigV4APreviouslyResolved,
   AwsSdkSigV4AuthInputConfig,
   AwsSdkSigV4AuthResolvedConfig,
   AwsSdkSigV4PreviouslyResolved,
+  resolveAwsSdkSigV4AConfig,
   resolveAwsSdkSigV4Config,
 } from "@aws-sdk/core";
 import { signatureV4CrtContainer } from "@aws-sdk/signature-v4-multi-region";
@@ -279,7 +283,7 @@ export const defaultEventBridgeHttpAuthSchemeProvider: EventBridgeHttpAuthScheme
 /**
  * @internal
  */
-export interface HttpAuthSchemeInputConfig extends AwsSdkSigV4AuthInputConfig {
+export interface HttpAuthSchemeInputConfig extends AwsSdkSigV4AuthInputConfig, AwsSdkSigV4AAuthInputConfig {
   /**
    * Configuration of HttpAuthSchemes for a client which provides default identity providers and signers per auth scheme.
    * @internal
@@ -296,7 +300,7 @@ export interface HttpAuthSchemeInputConfig extends AwsSdkSigV4AuthInputConfig {
 /**
  * @internal
  */
-export interface HttpAuthSchemeResolvedConfig extends AwsSdkSigV4AuthResolvedConfig {
+export interface HttpAuthSchemeResolvedConfig extends AwsSdkSigV4AuthResolvedConfig, AwsSdkSigV4AAuthResolvedConfig {
   /**
    * Configuration of HttpAuthSchemes for a client which provides default identity providers and signers per auth scheme.
    * @internal
@@ -314,10 +318,11 @@ export interface HttpAuthSchemeResolvedConfig extends AwsSdkSigV4AuthResolvedCon
  * @internal
  */
 export const resolveHttpAuthSchemeConfig = <T>(
-  config: T & HttpAuthSchemeInputConfig & AwsSdkSigV4PreviouslyResolved
+  config: T & HttpAuthSchemeInputConfig & AwsSdkSigV4PreviouslyResolved & AwsSdkSigV4APreviouslyResolved
 ): T & HttpAuthSchemeResolvedConfig => {
   const config_0 = resolveAwsSdkSigV4Config(config);
+  const config_1 = resolveAwsSdkSigV4AConfig(config_0);
   return {
-    ...config_0,
+    ...config_1,
   } as T & HttpAuthSchemeResolvedConfig;
 };
diff --git a/clients/client-eventbridge/src/runtimeConfig.ts b/clients/client-eventbridge/src/runtimeConfig.ts
index cfc6e176da83..b93a5f10e715 100644
--- a/clients/client-eventbridge/src/runtimeConfig.ts
+++ b/clients/client-eventbridge/src/runtimeConfig.ts
@@ -2,7 +2,7 @@
 // @ts-ignore: package.json will be imported from dist folders
 import packageInfo from "../package.json"; // eslint-disable-line
 
-import { emitWarningIfUnsupportedVersion as awsCheckVersion } from "@aws-sdk/core";
+import { NODE_SIGV4A_CONFIG_OPTIONS, emitWarningIfUnsupportedVersion as awsCheckVersion } from "@aws-sdk/core";
 import { defaultProvider as credentialDefaultProvider } from "@aws-sdk/credential-provider-node";
 import { defaultUserAgent } from "@aws-sdk/util-user-agent-node";
 import {
@@ -52,6 +52,7 @@ export const getRuntimeConfig = (config: EventBridgeClientConfig) => {
         default: async () => (await defaultConfigProvider()).retryMode || DEFAULT_RETRY_MODE,
       }),
     sha256: config?.sha256 ?? Hash.bind(null, "sha256"),
+    sigv4aSigningRegionSet: config?.sigv4aSigningRegionSet ?? loadNodeConfig(NODE_SIGV4A_CONFIG_OPTIONS),
     streamCollector: config?.streamCollector ?? streamCollector,
     useDualstackEndpoint: config?.useDualstackEndpoint ?? loadNodeConfig(NODE_USE_DUALSTACK_ENDPOINT_CONFIG_OPTIONS),
     useFipsEndpoint: config?.useFipsEndpoint ?? loadNodeConfig(NODE_USE_FIPS_ENDPOINT_CONFIG_OPTIONS),
diff --git a/clients/client-s3/src/auth/httpAuthSchemeProvider.ts b/clients/client-s3/src/auth/httpAuthSchemeProvider.ts
index 8f4b81934a5c..ea9fd5773dcd 100644
--- a/clients/client-s3/src/auth/httpAuthSchemeProvider.ts
+++ b/clients/client-s3/src/auth/httpAuthSchemeProvider.ts
@@ -1,8 +1,12 @@
 // smithy-typescript generated code
 import {
+  AwsSdkSigV4AAuthInputConfig,
+  AwsSdkSigV4AAuthResolvedConfig,
+  AwsSdkSigV4APreviouslyResolved,
   AwsSdkSigV4AuthInputConfig,
   AwsSdkSigV4AuthResolvedConfig,
   AwsSdkSigV4PreviouslyResolved,
+  resolveAwsSdkSigV4AConfig,
   resolveAwsSdkSigV4Config,
 } from "@aws-sdk/core";
 import { signatureV4CrtContainer } from "@aws-sdk/signature-v4-multi-region";
@@ -281,7 +285,7 @@ export const defaultS3HttpAuthSchemeProvider: S3HttpAuthSchemeProvider = createE
 /**
  * @internal
  */
-export interface HttpAuthSchemeInputConfig extends AwsSdkSigV4AuthInputConfig {
+export interface HttpAuthSchemeInputConfig extends AwsSdkSigV4AuthInputConfig, AwsSdkSigV4AAuthInputConfig {
   /**
    * Configuration of HttpAuthSchemes for a client which provides default identity providers and signers per auth scheme.
    * @internal
@@ -298,7 +302,7 @@ export interface HttpAuthSchemeInputConfig extends AwsSdkSigV4AuthInputConfig {
 /**
  * @internal
  */
-export interface HttpAuthSchemeResolvedConfig extends AwsSdkSigV4AuthResolvedConfig {
+export interface HttpAuthSchemeResolvedConfig extends AwsSdkSigV4AuthResolvedConfig, AwsSdkSigV4AAuthResolvedConfig {
   /**
    * Configuration of HttpAuthSchemes for a client which provides default identity providers and signers per auth scheme.
    * @internal
@@ -316,10 +320,11 @@ export interface HttpAuthSchemeResolvedConfig extends AwsSdkSigV4AuthResolvedCon
  * @internal
  */
 export const resolveHttpAuthSchemeConfig = <T>(
-  config: T & HttpAuthSchemeInputConfig & AwsSdkSigV4PreviouslyResolved
+  config: T & HttpAuthSchemeInputConfig & AwsSdkSigV4PreviouslyResolved & AwsSdkSigV4APreviouslyResolved
 ): T & HttpAuthSchemeResolvedConfig => {
   const config_0 = resolveAwsSdkSigV4Config(config);
+  const config_1 = resolveAwsSdkSigV4AConfig(config_0);
   return {
-    ...config_0,
+    ...config_1,
   } as T & HttpAuthSchemeResolvedConfig;
 };
diff --git a/clients/client-s3/src/runtimeConfig.ts b/clients/client-s3/src/runtimeConfig.ts
index a029bd3e80b0..89e08626ab8f 100644
--- a/clients/client-s3/src/runtimeConfig.ts
+++ b/clients/client-s3/src/runtimeConfig.ts
@@ -2,7 +2,7 @@
 // @ts-ignore: package.json will be imported from dist folders
 import packageInfo from "../package.json"; // eslint-disable-line
 
-import { emitWarningIfUnsupportedVersion as awsCheckVersion } from "@aws-sdk/core";
+import { NODE_SIGV4A_CONFIG_OPTIONS, emitWarningIfUnsupportedVersion as awsCheckVersion } from "@aws-sdk/core";
 import { defaultProvider as credentialDefaultProvider } from "@aws-sdk/credential-provider-node";
 import { NODE_USE_ARN_REGION_CONFIG_OPTIONS } from "@aws-sdk/middleware-bucket-endpoint";
 import { NODE_DISABLE_S3_EXPRESS_SESSION_AUTH_OPTIONS } from "@aws-sdk/middleware-sdk-s3";
@@ -62,6 +62,7 @@ export const getRuntimeConfig = (config: S3ClientConfig) => {
       }),
     sha1: config?.sha1 ?? Hash.bind(null, "sha1"),
     sha256: config?.sha256 ?? Hash.bind(null, "sha256"),
+    sigv4aSigningRegionSet: config?.sigv4aSigningRegionSet ?? loadNodeConfig(NODE_SIGV4A_CONFIG_OPTIONS),
     streamCollector: config?.streamCollector ?? streamCollector,
     streamHasher: config?.streamHasher ?? streamHasher,
     useArnRegion: config?.useArnRegion ?? loadNodeConfig(NODE_USE_ARN_REGION_CONFIG_OPTIONS),
diff --git a/codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/AwsTraitsUtils.java b/codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/AwsTraitsUtils.java
index 7828466f1016..f55183ac300a 100644
--- a/codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/AwsTraitsUtils.java
+++ b/codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/AwsTraitsUtils.java
@@ -60,12 +60,16 @@ public static boolean isSigV4Service(ServiceShape serviceShape) {
     }
 
     public static boolean isSigV4AsymmetricService(Model model, TypeScriptSettings settings) {
-        if (ENDPOINT_RULESET_HTTP_AUTH_SCHEME_SERVICES.contains(settings.getService())) {
+        return isSigV4AsymmetricService(model, settings.getService(model));
+    }
+
+    public static boolean isSigV4AsymmetricService(Model model, ServiceShape service) {
+        if (ENDPOINT_RULESET_HTTP_AUTH_SCHEME_SERVICES.contains(service.getId())) {
             return true;
         }
 
         return ServiceIndex.of(model)
-            .getEffectiveAuthSchemes(settings.getService(), ServiceIndex.AuthSchemeMode.NO_AUTH_AWARE)
+            .getEffectiveAuthSchemes(service, ServiceIndex.AuthSchemeMode.NO_AUTH_AWARE)
             .containsKey(SigV4ATrait.ID);
     }
 
diff --git a/codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/auth/http/integration/AwsSdkCustomizeSigV4Auth.java b/codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/auth/http/integration/AwsSdkCustomizeSigV4Auth.java
index 82d1ff08d548..e2619fa15f31 100644
--- a/codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/auth/http/integration/AwsSdkCustomizeSigV4Auth.java
+++ b/codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/auth/http/integration/AwsSdkCustomizeSigV4Auth.java
@@ -13,6 +13,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.TreeMap;
 import java.util.function.Consumer;
 import software.amazon.smithy.aws.traits.auth.SigV4ATrait;
 import software.amazon.smithy.aws.traits.auth.SigV4Trait;
@@ -104,7 +105,8 @@ public Map<String, Consumer<TypeScriptWriter>> getRuntimeConfigWriters(
                 }
             case NODE:
                 if (isAwsService(service)) {
-                    return MapUtils.of(
+                    Map<String, Consumer<TypeScriptWriter>> map = new TreeMap<String, Consumer<TypeScriptWriter>>();
+                    map.put(
                         "credentialDefaultProvider", writer -> {
                             writer
                                 .addDependency(AwsDependency.CREDENTIAL_PROVIDER_NODE)
@@ -114,6 +116,23 @@ public Map<String, Consumer<TypeScriptWriter>> getRuntimeConfigWriters(
                             AwsCredentialProviderUtils.addAwsCredentialProviderDependencies(service, writer);
                         }
                     );
+                    if (isSigV4AsymmetricService(model, settings)) {
+                        map.put(
+                            "sigv4aSigningRegionSet", writer -> {
+                                writer.addDependency(TypeScriptDependency.NODE_CONFIG_PROVIDER);
+                                writer.addDependency(AwsDependency.AWS_SDK_CORE);
+                                writer.addImport("loadConfig", "loadNodeConfig",
+                                    TypeScriptDependency.NODE_CONFIG_PROVIDER);
+                                writer.addImport(
+                                    "NODE_SIGV4A_CONFIG_OPTIONS",
+                                    null,
+                                    AwsDependency.AWS_SDK_CORE
+                                );
+                                writer.write("loadNodeConfig(NODE_SIGV4A_CONFIG_OPTIONS)");
+                            }
+                        );
+                    }
+                    return map;
                 }
             default:
                 return Collections.emptyMap();
@@ -180,6 +199,28 @@ public void customizeSupportedHttpAuthSchemes(
                     .getHttpAuthScheme(SigV4Trait.ID)
                     .toBuilder()
                     .schemeId(SigV4ATrait.ID)
+                    .addResolveConfigFunction(ResolveConfigFunction.builder()
+                        .resolveConfigFunction(Symbol.builder()
+                            .name("resolveAwsSdkSigV4AConfig")
+                            .namespace(AwsDependency.AWS_SDK_CORE.getPackageName(), "/")
+                            .addDependency(AwsDependency.AWS_SDK_CORE)
+                            .build())
+                        .inputConfig(Symbol.builder()
+                            .name("AwsSdkSigV4AAuthInputConfig")
+                            .namespace(AwsDependency.AWS_SDK_CORE.getPackageName(), "/")
+                            .addDependency(AwsDependency.AWS_SDK_CORE)
+                            .build())
+                        .previouslyResolved(Symbol.builder()
+                            .name("AwsSdkSigV4APreviouslyResolved")
+                            .namespace(AwsDependency.AWS_SDK_CORE.getPackageName(), "/")
+                            .addDependency(AwsDependency.AWS_SDK_CORE)
+                            .build())
+                        .resolvedConfig(Symbol.builder()
+                            .name("AwsSdkSigV4AAuthResolvedConfig")
+                            .namespace(AwsDependency.AWS_SDK_CORE.getPackageName(), "/")
+                            .addDependency(AwsDependency.AWS_SDK_CORE)
+                            .build())
+                        .build())
                     .putDefaultSigner(LanguageTarget.SHARED, w -> w
                         .addDependency(AwsDependency.AWS_SDK_CORE)
                         .addImport("AwsSdkSigV4ASigner", null, AwsDependency.AWS_SDK_CORE)
diff --git a/packages/core/package.json b/packages/core/package.json
index 0d05e67e439c..f27c52e92ea8 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -77,6 +77,7 @@
   "dependencies": {
     "@smithy/core": "^2.3.2",
     "@smithy/node-config-provider": "^3.1.4",
+    "@smithy/property-provider": "^3.1.3",
     "@smithy/protocol-http": "^4.1.0",
     "@smithy/signature-v4": "^4.1.0",
     "@smithy/smithy-client": "^3.1.12",
diff --git a/packages/core/src/submodules/httpAuthSchemes/aws_sdk/AwsSdkSigV4ASigner.ts b/packages/core/src/submodules/httpAuthSchemes/aws_sdk/AwsSdkSigV4ASigner.ts
index 7a8c657b6e41..097a06e6ecfe 100644
--- a/packages/core/src/submodules/httpAuthSchemes/aws_sdk/AwsSdkSigV4ASigner.ts
+++ b/packages/core/src/submodules/httpAuthSchemes/aws_sdk/AwsSdkSigV4ASigner.ts
@@ -22,7 +22,13 @@ export class AwsSdkSigV4ASigner extends AwsSdkSigV4Signer {
     const { config, signer, signingRegion, signingRegionSet, signingName } = await validateSigningProperties(
       signingProperties
     );
-    const multiRegionOverride: string | undefined = signingRegionSet?.join?.(",") ?? signingRegion;
+
+    const configResolvedSigningRegionSet = await config.sigv4aSigningRegionSet?.();
+
+    const multiRegionOverride: string | undefined = (
+      configResolvedSigningRegionSet ??
+      signingRegionSet ?? [signingRegion]
+    ).join(",");
 
     const signedRequest = await signer.sign(httpRequest, {
       signingDate: getSkewCorrectedDate(config.systemClockOffset),
diff --git a/packages/core/src/submodules/httpAuthSchemes/aws_sdk/AwsSdkSigV4Signer.ts b/packages/core/src/submodules/httpAuthSchemes/aws_sdk/AwsSdkSigV4Signer.ts
index b0f7d5245d93..02062dbe010b 100644
--- a/packages/core/src/submodules/httpAuthSchemes/aws_sdk/AwsSdkSigV4Signer.ts
+++ b/packages/core/src/submodules/httpAuthSchemes/aws_sdk/AwsSdkSigV4Signer.ts
@@ -11,6 +11,7 @@ import {
 } from "@smithy/types";
 
 import { getDateHeader, getSkewCorrectedDate, getUpdatedSystemClockOffset } from "../utils";
+import { AwsSdkSigV4AAuthResolvedConfig } from "./resolveAwsSdkSigV4AConfig";
 
 /**
  * @internal
@@ -25,7 +26,7 @@ const throwSigningPropertyError = <T>(name: string, property: T | undefined): T
 /**
  * @internal
  */
-interface AwsSdkSigV4Config {
+interface AwsSdkSigV4Config extends AwsSdkSigV4AAuthResolvedConfig {
   systemClockOffset: number;
   signer: (authScheme?: AuthScheme) => Promise<RequestSigner>;
 }
diff --git a/packages/core/src/submodules/httpAuthSchemes/aws_sdk/index.ts b/packages/core/src/submodules/httpAuthSchemes/aws_sdk/index.ts
index 62172b787785..fad9615bebf4 100644
--- a/packages/core/src/submodules/httpAuthSchemes/aws_sdk/index.ts
+++ b/packages/core/src/submodules/httpAuthSchemes/aws_sdk/index.ts
@@ -1,3 +1,4 @@
 export { AwsSdkSigV4Signer, AWSSDKSigV4Signer, validateSigningProperties } from "./AwsSdkSigV4Signer";
 export { AwsSdkSigV4ASigner } from "./AwsSdkSigV4ASigner";
+export * from "./resolveAwsSdkSigV4AConfig";
 export * from "./resolveAwsSdkSigV4Config";
diff --git a/packages/core/src/submodules/httpAuthSchemes/aws_sdk/resolveAwsSdkSigV4AConfig.ts b/packages/core/src/submodules/httpAuthSchemes/aws_sdk/resolveAwsSdkSigV4AConfig.ts
new file mode 100644
index 000000000000..9d210b451790
--- /dev/null
+++ b/packages/core/src/submodules/httpAuthSchemes/aws_sdk/resolveAwsSdkSigV4AConfig.ts
@@ -0,0 +1,67 @@
+import { normalizeProvider } from "@smithy/core";
+import { LoadedConfigSelectors } from "@smithy/node-config-provider";
+import { ProviderError } from "@smithy/property-provider";
+import { Profile, Provider } from "@smithy/types";
+
+/**
+ * @public
+ */
+export interface AwsSdkSigV4AAuthInputConfig {
+  /**
+   * This option will override the AWS sigv4a
+   * signing regionSet from any other source.
+   *
+   * The lookup order is:
+   * 1. this value
+   * 2. configuration file value of sigv4a_signing_region_set.
+   * 3. environment value of AWS_SIGV4A_SIGNING_REGION_SET.
+   * 4. signingRegionSet given by endpoint resolution.
+   * 5. the singular region of the SDK client.
+   */
+  sigv4aSigningRegionSet?: string[] | undefined | Provider<string[] | undefined>;
+}
+
+/**
+ * @internal
+ */
+export interface AwsSdkSigV4APreviouslyResolved {}
+
+/**
+ * @internal
+ */
+export interface AwsSdkSigV4AAuthResolvedConfig {
+  sigv4aSigningRegionSet: Provider<string[] | undefined>;
+}
+
+/**
+ * @internal
+ */
+export const resolveAwsSdkSigV4AConfig = <T>(
+  config: T & AwsSdkSigV4AAuthInputConfig & AwsSdkSigV4APreviouslyResolved
+): T & AwsSdkSigV4AAuthResolvedConfig => {
+  config.sigv4aSigningRegionSet = normalizeProvider(config.sigv4aSigningRegionSet ?? []);
+  return config as T & AwsSdkSigV4AAuthResolvedConfig;
+};
+
+/**
+ * @internal
+ */
+export const NODE_SIGV4A_CONFIG_OPTIONS: LoadedConfigSelectors<string[] | undefined> = {
+  environmentVariableSelector(env: Record<string, string | undefined>): string[] | undefined {
+    if (env.AWS_SIGV4A_SIGNING_REGION_SET) {
+      return env.AWS_SIGV4A_SIGNING_REGION_SET.split(",").map((_) => _.trim());
+    }
+    throw new ProviderError("AWS_SIGV4A_SIGNING_REGION_SET not set in env.", {
+      tryNextLink: true,
+    });
+  },
+  configFileSelector(profile: Profile): string[] | undefined {
+    if (profile.sigv4a_signing_region_set) {
+      return ((profile.sigv4a_signing_region_set as string) ?? "").split(",").map((_) => _.trim());
+    }
+    throw new ProviderError("sigv4a_signing_region_set not set in profile.", {
+      tryNextLink: true,
+    });
+  },
+  default: undefined,
+};
diff --git a/private/aws-client-api-test/src/client-interface-tests/client-s3/impl/initializeWithMaximalConfiguration.ts b/private/aws-client-api-test/src/client-interface-tests/client-s3/impl/initializeWithMaximalConfiguration.ts
index 4a8a568ef6d8..c6f7e9a9e992 100644
--- a/private/aws-client-api-test/src/client-interface-tests/client-s3/impl/initializeWithMaximalConfiguration.ts
+++ b/private/aws-client-api-test/src/client-interface-tests/client-s3/impl/initializeWithMaximalConfiguration.ts
@@ -119,6 +119,7 @@ export const initializeWithMaximalConfiguration = () => {
     useGlobalEndpoint: false,
     signingEscapePath: false,
     bucketEndpoint: false,
+    sigv4aSigningRegionSet: [],
   };
 
   const s3 = new S3Client(config);