diff --git a/payload_consumer/delta_performer.cc b/payload_consumer/delta_performer.cc
index af1baa4..7d837db 100644
--- a/payload_consumer/delta_performer.cc
+++ b/payload_consumer/delta_performer.cc
@@ -806,15 +806,32 @@
 
     auto generator = partition_update_generator::Create(boot_control_,
                                                         manifest_.block_size());
-    std::vector<PartitionUpdate> other_partitions;
+    std::vector<PartitionUpdate> untouched_static_partitions;
     TEST_AND_RETURN_FALSE(
         generator->GenerateOperationsForPartitionsNotInPayload(
             install_plan_->source_slot,
             install_plan_->target_slot,
             touched_partitions,
-            &other_partitions));
-    partitions_.insert(
-        partitions_.end(), other_partitions.begin(), other_partitions.end());
+            &untouched_static_partitions));
+    partitions_.insert(partitions_.end(),
+                       untouched_static_partitions.begin(),
+                       untouched_static_partitions.end());
+
+    // Save the untouched dynamic partitions in install plan.
+    std::vector<std::string> dynamic_partitions;
+    if (!boot_control_->GetDynamicPartitionControl()
+             ->ListDynamicPartitionsForSlot(install_plan_->source_slot,
+                                            &dynamic_partitions)) {
+      LOG(ERROR) << "Failed to load dynamic partitions from slot "
+                 << install_plan_->source_slot;
+      return false;
+    }
+    install_plan_->untouched_dynamic_partitions.clear();
+    for (const auto& name : dynamic_partitions) {
+      if (touched_partitions.find(name) == touched_partitions.end()) {
+        install_plan_->untouched_dynamic_partitions.push_back(name);
+      }
+    }
   }
 
   // Fill in the InstallPlan::partitions based on the partitions from the
diff --git a/payload_consumer/filesystem_verifier_action.cc b/payload_consumer/filesystem_verifier_action.cc
index 5b2b5f4..61917ea 100644
--- a/payload_consumer/filesystem_verifier_action.cc
+++ b/payload_consumer/filesystem_verifier_action.cc
@@ -28,6 +28,7 @@
 #include <base/bind.h>
 #include <brillo/data_encoding.h>
 #include <brillo/streams/file_stream.h>
+#include <base/strings/string_util.h>
 
 #include "update_engine/common/utils.h"
 
@@ -89,6 +90,20 @@
 
 void FilesystemVerifierAction::StartPartitionHashing() {
   if (partition_index_ == install_plan_.partitions.size()) {
+    if (!install_plan_.untouched_dynamic_partitions.empty()) {
+      LOG(INFO) << "Verifying extents of untouched dynamic partitions ["
+                << base::JoinString(install_plan_.untouched_dynamic_partitions,
+                                    ", ")
+                << "]";
+      if (!dynamic_control_->VerifyExtentsForUntouchedPartitions(
+              install_plan_.source_slot,
+              install_plan_.target_slot,
+              install_plan_.untouched_dynamic_partitions)) {
+        Cleanup(ErrorCode::kFilesystemVerifierError);
+        return;
+      }
+    }
+
     Cleanup(ErrorCode::kSuccess);
     return;
   }
diff --git a/payload_consumer/filesystem_verifier_action.h b/payload_consumer/filesystem_verifier_action.h
index 7d179df..6a8823a 100644
--- a/payload_consumer/filesystem_verifier_action.h
+++ b/payload_consumer/filesystem_verifier_action.h
@@ -57,8 +57,13 @@
 
 class FilesystemVerifierAction : public InstallPlanAction {
  public:
-  FilesystemVerifierAction()
-      : verity_writer_(verity_writer::CreateVerityWriter()) {}
+  explicit FilesystemVerifierAction(
+      DynamicPartitionControlInterface* dynamic_control)
+      : verity_writer_(verity_writer::CreateVerityWriter()),
+        dynamic_control_(dynamic_control) {
+    CHECK(dynamic_control_);
+  }
+
   ~FilesystemVerifierAction() override = default;
 
   void PerformAction() override;
@@ -123,6 +128,9 @@
   // Write verity data of the current partition.
   std::unique_ptr<VerityWriterInterface> verity_writer_;
 
+  // Verifies the untouched dynamic partitions for partial updates.
+  DynamicPartitionControlInterface* dynamic_control_{nullptr};
+
   // Reads and hashes this many bytes from the head of the input stream. When
   // the partition starts to be hashed, this field is initialized from the
   // corresponding InstallPlan::Partition size which is the total size
diff --git a/payload_consumer/filesystem_verifier_action_unittest.cc b/payload_consumer/filesystem_verifier_action_unittest.cc
index cb33404..2971849 100644
--- a/payload_consumer/filesystem_verifier_action_unittest.cc
+++ b/payload_consumer/filesystem_verifier_action_unittest.cc
@@ -27,6 +27,7 @@
 #include <brillo/secure_blob.h>
 #include <gtest/gtest.h>
 
+#include "update_engine/common/dynamic_partition_control_stub.h"
 #include "update_engine/common/hash_calculator.h"
 #include "update_engine/common/test_utils.h"
 #include "update_engine/common/utils.h"
@@ -51,6 +52,7 @@
 
   brillo::FakeMessageLoop loop_{nullptr};
   ActionProcessor processor_;
+  DynamicPartitionControlStub dynamic_control_stub_;
 };
 
 class FilesystemVerifierActionTestDelegate : public ActionProcessorDelegate {
@@ -188,7 +190,8 @@
 void FilesystemVerifierActionTest::BuildActions(
     const InstallPlan& install_plan) {
   auto feeder_action = std::make_unique<ObjectFeederAction<InstallPlan>>();
-  auto verifier_action = std::make_unique<FilesystemVerifierAction>();
+  auto verifier_action =
+      std::make_unique<FilesystemVerifierAction>(&dynamic_control_stub_);
   auto collector_action =
       std::make_unique<ObjectCollectorAction<InstallPlan>>();
 
@@ -217,7 +220,8 @@
 };
 
 TEST_F(FilesystemVerifierActionTest, MissingInputObjectTest) {
-  auto copier_action = std::make_unique<FilesystemVerifierAction>();
+  auto copier_action =
+      std::make_unique<FilesystemVerifierAction>(&dynamic_control_stub_);
   auto collector_action =
       std::make_unique<ObjectCollectorAction<InstallPlan>>();
 
diff --git a/payload_consumer/install_plan.h b/payload_consumer/install_plan.h
index 63178bd..f04c650 100644
--- a/payload_consumer/install_plan.h
+++ b/payload_consumer/install_plan.h
@@ -158,6 +158,10 @@
   // If not blank, a base-64 encoded representation of the PEM-encoded
   // public key in the response.
   std::string public_key_rsa;
+
+  // The name of dynamic partitions not included in the payload. Only used
+  // for partial updates.
+  std::vector<std::string> untouched_dynamic_partitions;
 };
 
 class InstallPlanAction;
diff --git a/payload_consumer/partition_update_generator_android.cc b/payload_consumer/partition_update_generator_android.cc
index aa3f2e5..5768dd6 100644
--- a/payload_consumer/partition_update_generator_android.cc
+++ b/payload_consumer/partition_update_generator_android.cc
@@ -50,25 +50,14 @@
         BootControlInterface::Slot target_slot,
         const std::set<std::string>& partitions_in_payload,
         std::vector<PartitionUpdate>* update_list) {
-  auto ret = GetStaticAbPartitionsOnDevice();
-  if (!ret.has_value()) {
+  auto ab_partitions = GetStaticAbPartitionsOnDevice();
+  if (!ab_partitions.has_value()) {
     LOG(ERROR) << "Failed to load static a/b partitions";
     return false;
   }
-  auto ab_partitions = ret.value();
-
-  // Add the dynamic partitions.
-  auto dynamic_control = boot_control_->GetDynamicPartitionControl();
-  std::vector<std::string> dynamic_partitions;
-  if (!dynamic_control->ListDynamicPartitionsForSlot(source_slot,
-                                                     &dynamic_partitions)) {
-    LOG(ERROR) << "Failed to load dynamic partitions from slot " << source_slot;
-    return false;
-  }
-  ab_partitions.insert(dynamic_partitions.begin(), dynamic_partitions.end());
 
   std::vector<PartitionUpdate> partition_updates;
-  for (const auto& partition_name : ab_partitions) {
+  for (const auto& partition_name : ab_partitions.value()) {
     if (partitions_in_payload.find(partition_name) !=
         partitions_in_payload.end()) {
       LOG(INFO) << partition_name << " has included in payload";
@@ -159,13 +148,15 @@
     return std::nullopt;
   }
 
-  if (is_source_dynamic != is_target_dynamic) {
-    LOG(ERROR) << "Source slot " << source_slot << " for partition "
-               << partition_name << " is " << (is_source_dynamic ? "" : "not")
-               << " dynamic, but target slot " << target_slot << " is "
+  if (is_source_dynamic || is_target_dynamic) {
+    LOG(ERROR) << "Partition " << partition_name << " is expected to be a"
+               << " static partition. source slot is "
+               << (is_source_dynamic ? "" : "not")
+               << " dynamic, and target slot " << target_slot << " is "
                << (is_target_dynamic ? "" : "not") << " dynamic.";
     return std::nullopt;
   }
+
   auto source_size = utils::FileSize(source_device);
   auto target_size = utils::FileSize(target_device);
   if (source_size == -1 || target_size == -1 || source_size != target_size ||
@@ -175,11 +166,8 @@
     return std::nullopt;
   }
 
-  return CreatePartitionUpdate(partition_name,
-                               source_device,
-                               target_device,
-                               source_size,
-                               is_source_dynamic);
+  return CreatePartitionUpdate(
+      partition_name, source_device, target_device, source_size);
 }
 
 std::optional<PartitionUpdate>
@@ -187,8 +175,7 @@
     const std::string& partition_name,
     const std::string& source_device,
     const std::string& target_device,
-    int64_t partition_size,
-    bool is_dynamic) {
+    int64_t partition_size) {
   PartitionUpdate partition_update;
   partition_update.set_partition_name(partition_name);
   auto old_partition_info = partition_update.mutable_old_partition_info();
@@ -202,18 +189,15 @@
   auto new_partition_info = partition_update.mutable_new_partition_info();
   new_partition_info->set_size(partition_size);
   new_partition_info->set_hash(raw_hash->data(), raw_hash->size());
-  // TODO(xunchang) TBD, should we skip hashing and verification of the
-  // dynamic partitions not in payload?
-  if (!is_dynamic) {
-    auto copy_operation = partition_update.add_operations();
-    copy_operation->set_type(InstallOperation::SOURCE_COPY);
-    Extent copy_extent;
-    copy_extent.set_start_block(0);
-    copy_extent.set_num_blocks(partition_size / block_size_);
 
-    *copy_operation->add_src_extents() = copy_extent;
-    *copy_operation->add_dst_extents() = copy_extent;
-  }
+  auto copy_operation = partition_update.add_operations();
+  copy_operation->set_type(InstallOperation::SOURCE_COPY);
+  Extent copy_extent;
+  copy_extent.set_start_block(0);
+  copy_extent.set_num_blocks(partition_size / block_size_);
+
+  *copy_operation->add_src_extents() = copy_extent;
+  *copy_operation->add_dst_extents() = copy_extent;
 
   return partition_update;
 }
diff --git a/payload_consumer/partition_update_generator_android.h b/payload_consumer/partition_update_generator_android.h
index 8f33077..97b7d83 100644
--- a/payload_consumer/partition_update_generator_android.h
+++ b/payload_consumer/partition_update_generator_android.h
@@ -56,8 +56,7 @@
       const std::string& partition_name,
       const std::string& source_device,
       const std::string& target_device,
-      int64_t partition_size,
-      bool is_dynamic);
+      int64_t partition_size);
 
   std::optional<PartitionUpdate> CreatePartitionUpdate(
       const std::string& partition_name,