diff --git a/src/main/java/com/google/api/generator/gapic/composer/SampleCodeHelperComposer.java b/src/main/java/com/google/api/generator/gapic/composer/SampleCodeHelperComposer.java
index 7afacdbcbd..99aa9061d6 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/SampleCodeHelperComposer.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/SampleCodeHelperComposer.java
@@ -15,6 +15,7 @@
 package com.google.api.generator.gapic.composer;
 
 import com.google.api.core.ApiFuture;
+import com.google.api.gax.longrunning.OperationFuture;
 import com.google.api.gax.rpc.ApiStreamObserver;
 import com.google.api.gax.rpc.BidiStream;
 import com.google.api.gax.rpc.ServerStream;
@@ -46,6 +47,7 @@
 import com.google.api.generator.gapic.model.MethodArgument;
 import com.google.api.generator.gapic.model.ResourceName;
 import com.google.api.generator.gapic.utils.JavaStyle;
+import com.google.longrunning.Operation;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -64,6 +66,7 @@ public final class SampleCodeHelperComposer {
   private static String UNARY_CALLABLE_NAME_PATTERN = "%sCallable";
   private static String PAGED_CALLABLE_NAME_PATTERN = "%sPagedCallable";
   private static String PAGED_RESPONSE_NAME_PATTERN = "%sPagedResponse";
+  private static String OPERATION_CALLABLE_NAME_PATTERN = "%sOperationCallable";
 
   public static TryCatchStatement composeRpcMethodSampleCode(
       Method method,
@@ -533,12 +536,117 @@ private static TryCatchStatement composeLroRpcCallableMethodSampleCode(
       TypeNode clientType,
       TypeNode returnType,
       Map<String, ResourceName> resourceNames) {
+    // Initialize the method's arguments with default values.
+    List<MethodArgument> arguments =
+        method.methodSignatures().isEmpty()
+            ? Collections.emptyList()
+            : method.methodSignatures().get(0);
+    List<Statement> bodyStatements =
+        arguments.stream()
+            .map(
+                methodArg ->
+                    ExprStatement.withExpr(
+                        assignMethodArgumentWithDefaultValue(methodArg, resourceNames)))
+            .collect(Collectors.toList());
+    // Build request Variable Epxr with set attributes.
+    bodyStatements.add(
+        ExprStatement.withExpr(createRequestBuilderExpr(method.inputType(), arguments)));
+
+    // If return type has 3 generics, add statements for OperationCallable method.
+    // otherwise, add statements for callable method.
+    if (returnType.reference().generics().size() == 3) {
+      // Initialize operation future variable with operation callable method.
+      // e.g.OperationFuture<WaitResponse, WaitMetadata> future =
+      // echoClient.waitOperationCallable().futureCall(request);
+      TypeNode operationFutureType =
+          TypeNode.withReference(
+              ConcreteReference.builder()
+                  .setClazz(OperationFuture.class)
+                  .setGenerics(method.inputType().reference(), method.outputType().reference())
+                  .build());
+      VariableExpr operationFutureVarExpr = createVariableExpr(FUTURE, operationFutureType);
+      MethodInvocationExpr futureCallMethodExpr =
+          MethodInvocationExpr.builder()
+              .setExprReferenceExpr(
+                  MethodInvocationExpr.builder()
+                      .setExprReferenceExpr(
+                          createVariableExpr(getClientName(clientType), clientType))
+                      .setMethodName(getOperationCallableName(method.name()))
+                      .build())
+              .setArguments(createVariableExpr(REQUEST, method.inputType()))
+              .setMethodName("futureCall")
+              .setReturnType(operationFutureType)
+              .build();
+      bodyStatements.add(
+          ExprStatement.withExpr(
+              AssignmentExpr.builder()
+                  .setVariableExpr(operationFutureVarExpr.toBuilder().setIsDecl(true).build())
+                  .setValueExpr(futureCallMethodExpr)
+                  .build()));
+      // Create comment line
+      bodyStatements.add(createLineCommentStatement("Do something."));
+      // Assign response variable with get method.
+      // e.g. WaitResponse response = future.get();
+      TypeNode waitResponseType = TypeNode.withReference(returnType.reference().generics().get(1));
+      bodyStatements.add(
+          ExprStatement.withExpr(
+              AssignmentExpr.builder()
+                  .setVariableExpr(createVariableDeclExpr(RESPONSE, waitResponseType))
+                  .setValueExpr(
+                      MethodInvocationExpr.builder()
+                          .setExprReferenceExpr(operationFutureVarExpr)
+                          .setMethodName("get")
+                          .setReturnType(waitResponseType)
+                          .build())
+                  .build()));
+    } else {
+      // Initialize Api future variable with callable method.
+      // e.g ApiFuture<Operation> future = echoClient.waitCallable().futureCall(request);
+      TypeNode apiFutureType =
+          TypeNode.withReference(
+              ConcreteReference.builder()
+                  .setClazz(ApiFuture.class)
+                  .setGenerics(ConcreteReference.withClazz(Operation.class))
+                  .build());
+      VariableExpr apiFutureVarExpr = createVariableExpr("future", apiFutureType);
+      MethodInvocationExpr futureCallMethodExpr =
+          MethodInvocationExpr.builder()
+              .setExprReferenceExpr(
+                  MethodInvocationExpr.builder()
+                      .setExprReferenceExpr(
+                          createVariableExpr(getClientName(clientType), clientType))
+                      .setMethodName(getCallableMethodName(method.name()))
+                      .build())
+              .setMethodName("futureCall")
+              .setArguments(createVariableExpr(REQUEST, method.inputType()))
+              .setReturnType(apiFutureType)
+              .build();
+      bodyStatements.add(
+          ExprStatement.withExpr(
+              AssignmentExpr.builder()
+                  .setVariableExpr(apiFutureVarExpr.toBuilder().setIsDecl(true).build())
+                  .setValueExpr(futureCallMethodExpr)
+                  .build()));
+      // Create comment line
+      bodyStatements.add(createLineCommentStatement("Do something."));
+      // Assign response variable with get method.
+      // e.g. Operation response = future.get();
+      bodyStatements.add(
+          ExprStatement.withExpr(
+              AssignmentExpr.builder()
+                  .setVariableExpr(createVariableDeclExpr(RESPONSE, method.outputType()))
+                  .setValueExpr(
+                      MethodInvocationExpr.builder()
+                          .setExprReferenceExpr(apiFutureVarExpr)
+                          .setMethodName("get")
+                          .setReturnType(method.outputType())
+                          .build())
+                  .build()));
+    }
+
     return TryCatchStatement.builder()
         .setTryResourceExpr(assignClientVariableWithCreateMethodExpr(clientType))
-        .setTryBody(
-            Arrays.asList(
-                createLineCommentStatement(
-                    "Note: Not implement yet, placeholder for Lro Rpc callable methods' sample code.")))
+        .setTryBody(bodyStatements)
         .setIsSampleCode(true)
         .build();
   }
@@ -899,6 +1007,10 @@ private static String getPagedCallableName(String methodName) {
     return JavaStyle.toLowerCamelCase(String.format(PAGED_CALLABLE_NAME_PATTERN, methodName));
   }
 
+  private static String getOperationCallableName(String methodName) {
+    return JavaStyle.toLowerCamelCase(String.format(OPERATION_CALLABLE_NAME_PATTERN, methodName));
+  }
+
   private static CommentStatement createLineCommentStatement(String content) {
     return CommentStatement.withComment(LineComment.withComment(content));
   }
diff --git a/src/test/java/com/google/api/generator/gapic/composer/goldens/EchoClient.golden b/src/test/java/com/google/api/generator/gapic/composer/goldens/EchoClient.golden
index 2ebdf81cea..315fab6742 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/goldens/EchoClient.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/goldens/EchoClient.golden
@@ -542,7 +542,12 @@ public class EchoClient implements BackgroundResource {
    *
    * <pre>{@code
    * try (EchoClient echoClient = EchoClient.create()) {
-   *   // Note: Not implement yet, placeholder for Lro Rpc callable methods' sample code.
+   *   Duration ttl = Duration.newBuilder().build();
+   *   WaitRequest request = WaitRequest.newBuilder().setTtl(ttl).build();
+   *   OperationFuture<WaitRequest, Operation> future =
+   *       echoClient.waitOperationCallable().futureCall(request);
+   *   // Do something.
+   *   WaitResponse response = future.get();
    * }
    * }</pre>
    */
@@ -556,7 +561,11 @@ public class EchoClient implements BackgroundResource {
    *
    * <pre>{@code
    * try (EchoClient echoClient = EchoClient.create()) {
-   *   // Note: Not implement yet, placeholder for Lro Rpc callable methods' sample code.
+   *   Duration ttl = Duration.newBuilder().build();
+   *   WaitRequest request = WaitRequest.newBuilder().setTtl(ttl).build();
+   *   ApiFuture<Operation> future = echoClient.waitCallable().futureCall(request);
+   *   // Do something.
+   *   Operation response = future.get();
    * }
    * }</pre>
    */
diff --git a/test/integration/goldens/asset/AssetServiceClient.java b/test/integration/goldens/asset/AssetServiceClient.java
index 6e7d225027..43cbe6093f 100644
--- a/test/integration/goldens/asset/AssetServiceClient.java
+++ b/test/integration/goldens/asset/AssetServiceClient.java
@@ -198,7 +198,11 @@ public final OperationFuture<ExportAssetsResponse, ExportAssetsRequest> exportAs
    *
    * <pre>{@code
    * try (AssetServiceClient assetServiceClient = AssetServiceClient.create()) {
-   *   // Note: Not implement yet, placeholder for Lro Rpc callable methods' sample code.
+   *   ExportAssetsRequest request = ExportAssetsRequest.newBuilder().build();
+   *   OperationFuture<ExportAssetsRequest, Operation> future =
+   *       assetServiceClient.exportAssetsOperationCallable().futureCall(request);
+   *   // Do something.
+   *   ExportAssetsResponse response = future.get();
    * }
    * }</pre>
    */
@@ -222,7 +226,10 @@ public final OperationFuture<ExportAssetsResponse, ExportAssetsRequest> exportAs
    *
    * <pre>{@code
    * try (AssetServiceClient assetServiceClient = AssetServiceClient.create()) {
-   *   // Note: Not implement yet, placeholder for Lro Rpc callable methods' sample code.
+   *   ExportAssetsRequest request = ExportAssetsRequest.newBuilder().build();
+   *   ApiFuture<Operation> future = assetServiceClient.exportAssetsCallable().futureCall(request);
+   *   // Do something.
+   *   Operation response = future.get();
    * }
    * }</pre>
    */
diff --git a/test/integration/goldens/redis/CloudRedisClient.java b/test/integration/goldens/redis/CloudRedisClient.java
index 09d6ee57b9..d5a14046fd 100644
--- a/test/integration/goldens/redis/CloudRedisClient.java
+++ b/test/integration/goldens/redis/CloudRedisClient.java
@@ -605,7 +605,19 @@ public final OperationFuture<Instance, OperationMetadata> createInstanceAsync(
    *
    * <pre>{@code
    * try (CloudRedisClient cloudRedisClient = CloudRedisClient.create()) {
-   *   // Note: Not implement yet, placeholder for Lro Rpc callable methods' sample code.
+   *   LocationName parent = LocationName.of("[PROJECT]", "[LOCATION]");
+   *   String instance_id = "instance_id-2101995259";
+   *   Instance instance = Instance.newBuilder().build();
+   *   CreateInstanceRequest request =
+   *       CreateInstanceRequest.newBuilder()
+   *           .setParent(parent)
+   *           .setInstanceId(instance_id)
+   *           .setInstance(instance)
+   *           .build();
+   *   OperationFuture<CreateInstanceRequest, Operation> future =
+   *       cloudRedisClient.createInstanceOperationCallable().futureCall(request);
+   *   // Do something.
+   *   Instance response = future.get();
    * }
    * }</pre>
    */
@@ -633,7 +645,18 @@ public final OperationFuture<Instance, OperationMetadata> createInstanceAsync(
    *
    * <pre>{@code
    * try (CloudRedisClient cloudRedisClient = CloudRedisClient.create()) {
-   *   // Note: Not implement yet, placeholder for Lro Rpc callable methods' sample code.
+   *   LocationName parent = LocationName.of("[PROJECT]", "[LOCATION]");
+   *   String instance_id = "instance_id-2101995259";
+   *   Instance instance = Instance.newBuilder().build();
+   *   CreateInstanceRequest request =
+   *       CreateInstanceRequest.newBuilder()
+   *           .setParent(parent)
+   *           .setInstanceId(instance_id)
+   *           .setInstance(instance)
+   *           .build();
+   *   ApiFuture<Operation> future = cloudRedisClient.createInstanceCallable().futureCall(request);
+   *   // Do something.
+   *   Operation response = future.get();
    * }
    * }</pre>
    */
@@ -716,7 +739,17 @@ public final OperationFuture<Instance, OperationMetadata> updateInstanceAsync(
    *
    * <pre>{@code
    * try (CloudRedisClient cloudRedisClient = CloudRedisClient.create()) {
-   *   // Note: Not implement yet, placeholder for Lro Rpc callable methods' sample code.
+   *   FieldMask update_mask = FieldMask.newBuilder().build();
+   *   Instance instance = Instance.newBuilder().build();
+   *   UpdateInstanceRequest request =
+   *       UpdateInstanceRequest.newBuilder()
+   *           .setUpdateMask(update_mask)
+   *           .setInstance(instance)
+   *           .build();
+   *   OperationFuture<UpdateInstanceRequest, Operation> future =
+   *       cloudRedisClient.updateInstanceOperationCallable().futureCall(request);
+   *   // Do something.
+   *   Instance response = future.get();
    * }
    * }</pre>
    */
@@ -737,7 +770,16 @@ public final OperationFuture<Instance, OperationMetadata> updateInstanceAsync(
    *
    * <pre>{@code
    * try (CloudRedisClient cloudRedisClient = CloudRedisClient.create()) {
-   *   // Note: Not implement yet, placeholder for Lro Rpc callable methods' sample code.
+   *   FieldMask update_mask = FieldMask.newBuilder().build();
+   *   Instance instance = Instance.newBuilder().build();
+   *   UpdateInstanceRequest request =
+   *       UpdateInstanceRequest.newBuilder()
+   *           .setUpdateMask(update_mask)
+   *           .setInstance(instance)
+   *           .build();
+   *   ApiFuture<Operation> future = cloudRedisClient.updateInstanceCallable().futureCall(request);
+   *   // Do something.
+   *   Operation response = future.get();
    * }
    * }</pre>
    */
@@ -834,7 +876,14 @@ public final OperationFuture<Instance, OperationMetadata> upgradeInstanceAsync(
    *
    * <pre>{@code
    * try (CloudRedisClient cloudRedisClient = CloudRedisClient.create()) {
-   *   // Note: Not implement yet, placeholder for Lro Rpc callable methods' sample code.
+   *   InstanceName name = InstanceName.of("[PROJECT]", "[LOCATION]", "[INSTANCE]");
+   *   String redis_version = "redis_version-685310444";
+   *   UpgradeInstanceRequest request =
+   *       UpgradeInstanceRequest.newBuilder().setName(name).setRedisVersion(redis_version).build();
+   *   OperationFuture<UpgradeInstanceRequest, Operation> future =
+   *       cloudRedisClient.upgradeInstanceOperationCallable().futureCall(request);
+   *   // Do something.
+   *   Instance response = future.get();
    * }
    * }</pre>
    */
@@ -851,7 +900,13 @@ public final OperationFuture<Instance, OperationMetadata> upgradeInstanceAsync(
    *
    * <pre>{@code
    * try (CloudRedisClient cloudRedisClient = CloudRedisClient.create()) {
-   *   // Note: Not implement yet, placeholder for Lro Rpc callable methods' sample code.
+   *   InstanceName name = InstanceName.of("[PROJECT]", "[LOCATION]", "[INSTANCE]");
+   *   String redis_version = "redis_version-685310444";
+   *   UpgradeInstanceRequest request =
+   *       UpgradeInstanceRequest.newBuilder().setName(name).setRedisVersion(redis_version).build();
+   *   ApiFuture<Operation> future = cloudRedisClient.upgradeInstanceCallable().futureCall(request);
+   *   // Do something.
+   *   Operation response = future.get();
    * }
    * }</pre>
    */
@@ -936,7 +991,14 @@ public final OperationFuture<Instance, OperationMetadata> importInstanceAsync(
    *
    * <pre>{@code
    * try (CloudRedisClient cloudRedisClient = CloudRedisClient.create()) {
-   *   // Note: Not implement yet, placeholder for Lro Rpc callable methods' sample code.
+   *   String name = "name3373707";
+   *   InputConfig input_config = InputConfig.newBuilder().build();
+   *   ImportInstanceRequest request =
+   *       ImportInstanceRequest.newBuilder().setName(name).setInputConfig(input_config).build();
+   *   OperationFuture<ImportInstanceRequest, Operation> future =
+   *       cloudRedisClient.importInstanceOperationCallable().futureCall(request);
+   *   // Do something.
+   *   Instance response = future.get();
    * }
    * }</pre>
    */
@@ -959,7 +1021,13 @@ public final OperationFuture<Instance, OperationMetadata> importInstanceAsync(
    *
    * <pre>{@code
    * try (CloudRedisClient cloudRedisClient = CloudRedisClient.create()) {
-   *   // Note: Not implement yet, placeholder for Lro Rpc callable methods' sample code.
+   *   String name = "name3373707";
+   *   InputConfig input_config = InputConfig.newBuilder().build();
+   *   ImportInstanceRequest request =
+   *       ImportInstanceRequest.newBuilder().setName(name).setInputConfig(input_config).build();
+   *   ApiFuture<Operation> future = cloudRedisClient.importInstanceCallable().futureCall(request);
+   *   // Do something.
+   *   Operation response = future.get();
    * }
    * }</pre>
    */
@@ -1041,7 +1109,14 @@ public final OperationFuture<Instance, OperationMetadata> exportInstanceAsync(
    *
    * <pre>{@code
    * try (CloudRedisClient cloudRedisClient = CloudRedisClient.create()) {
-   *   // Note: Not implement yet, placeholder for Lro Rpc callable methods' sample code.
+   *   String name = "name3373707";
+   *   OutputConfig output_config = OutputConfig.newBuilder().build();
+   *   ExportInstanceRequest request =
+   *       ExportInstanceRequest.newBuilder().setName(name).setOutputConfig(output_config).build();
+   *   OperationFuture<ExportInstanceRequest, Operation> future =
+   *       cloudRedisClient.exportInstanceOperationCallable().futureCall(request);
+   *   // Do something.
+   *   Instance response = future.get();
    * }
    * }</pre>
    */
@@ -1063,7 +1138,13 @@ public final OperationFuture<Instance, OperationMetadata> exportInstanceAsync(
    *
    * <pre>{@code
    * try (CloudRedisClient cloudRedisClient = CloudRedisClient.create()) {
-   *   // Note: Not implement yet, placeholder for Lro Rpc callable methods' sample code.
+   *   String name = "name3373707";
+   *   OutputConfig output_config = OutputConfig.newBuilder().build();
+   *   ExportInstanceRequest request =
+   *       ExportInstanceRequest.newBuilder().setName(name).setOutputConfig(output_config).build();
+   *   ApiFuture<Operation> future = cloudRedisClient.exportInstanceCallable().futureCall(request);
+   *   // Do something.
+   *   Operation response = future.get();
    * }
    * }</pre>
    */
@@ -1175,7 +1256,18 @@ public final OperationFuture<Instance, OperationMetadata> failoverInstanceAsync(
    *
    * <pre>{@code
    * try (CloudRedisClient cloudRedisClient = CloudRedisClient.create()) {
-   *   // Note: Not implement yet, placeholder for Lro Rpc callable methods' sample code.
+   *   InstanceName name = InstanceName.of("[PROJECT]", "[LOCATION]", "[INSTANCE]");
+   *   FailoverInstanceRequest.DataProtectionMode data_protection_mode =
+   *       FailoverInstanceRequest.DataProtectionMode.forNumber(0);
+   *   FailoverInstanceRequest request =
+   *       FailoverInstanceRequest.newBuilder()
+   *           .setName(name)
+   *           .setDataProtectionMode(data_protection_mode)
+   *           .build();
+   *   OperationFuture<FailoverInstanceRequest, Operation> future =
+   *       cloudRedisClient.failoverInstanceOperationCallable().futureCall(request);
+   *   // Do something.
+   *   Instance response = future.get();
    * }
    * }</pre>
    */
@@ -1193,7 +1285,17 @@ public final OperationFuture<Instance, OperationMetadata> failoverInstanceAsync(
    *
    * <pre>{@code
    * try (CloudRedisClient cloudRedisClient = CloudRedisClient.create()) {
-   *   // Note: Not implement yet, placeholder for Lro Rpc callable methods' sample code.
+   *   InstanceName name = InstanceName.of("[PROJECT]", "[LOCATION]", "[INSTANCE]");
+   *   FailoverInstanceRequest.DataProtectionMode data_protection_mode =
+   *       FailoverInstanceRequest.DataProtectionMode.forNumber(0);
+   *   FailoverInstanceRequest request =
+   *       FailoverInstanceRequest.newBuilder()
+   *           .setName(name)
+   *           .setDataProtectionMode(data_protection_mode)
+   *           .build();
+   *   ApiFuture<Operation> future = cloudRedisClient.failoverInstanceCallable().futureCall(request);
+   *   // Do something.
+   *   Operation response = future.get();
    * }
    * }</pre>
    */
@@ -1280,7 +1382,12 @@ public final OperationFuture<Empty, OperationMetadata> deleteInstanceAsync(
    *
    * <pre>{@code
    * try (CloudRedisClient cloudRedisClient = CloudRedisClient.create()) {
-   *   // Note: Not implement yet, placeholder for Lro Rpc callable methods' sample code.
+   *   InstanceName name = InstanceName.of("[PROJECT]", "[LOCATION]", "[INSTANCE]");
+   *   DeleteInstanceRequest request = DeleteInstanceRequest.newBuilder().setName(name).build();
+   *   OperationFuture<DeleteInstanceRequest, Operation> future =
+   *       cloudRedisClient.deleteInstanceOperationCallable().futureCall(request);
+   *   // Do something.
+   *   Empty response = future.get();
    * }
    * }</pre>
    */
@@ -1297,7 +1404,11 @@ public final OperationFuture<Empty, OperationMetadata> deleteInstanceAsync(
    *
    * <pre>{@code
    * try (CloudRedisClient cloudRedisClient = CloudRedisClient.create()) {
-   *   // Note: Not implement yet, placeholder for Lro Rpc callable methods' sample code.
+   *   InstanceName name = InstanceName.of("[PROJECT]", "[LOCATION]", "[INSTANCE]");
+   *   DeleteInstanceRequest request = DeleteInstanceRequest.newBuilder().setName(name).build();
+   *   ApiFuture<Operation> future = cloudRedisClient.deleteInstanceCallable().futureCall(request);
+   *   // Do something.
+   *   Operation response = future.get();
    * }
    * }</pre>
    */