diff --git a/test/src/test-cppapi-aggregates.cc b/test/src/test-cppapi-aggregates.cc
index 9be386a0d547..909320ffd265 100644
--- a/test/src/test-cppapi-aggregates.cc
+++ b/test/src/test-cppapi-aggregates.cc
@@ -35,7 +35,6 @@
 #include "tiledb/sm/cpp_api/tiledb"
 #include "tiledb/sm/cpp_api/tiledb_experimental"
 #include "tiledb/sm/query/readers/aggregators/count_aggregator.h"
-#include "tiledb/sm/query/readers/aggregators/mean_aggregator.h"
 #include "tiledb/sm/query/readers/aggregators/min_max_aggregator.h"
 #include "tiledb/sm/query/readers/aggregators/sum_aggregator.h"
 
diff --git a/tiledb/CMakeLists.txt b/tiledb/CMakeLists.txt
index 07acc6d27cfc..641d23810d9b 100644
--- a/tiledb/CMakeLists.txt
+++ b/tiledb/CMakeLists.txt
@@ -253,7 +253,6 @@ set(TILEDB_CORE_SOURCES
   ${TILEDB_CORE_INCLUDE_DIR}/tiledb/sm/query/query_condition.cc
   ${TILEDB_CORE_INCLUDE_DIR}/tiledb/sm/query/query_remote_buffer_storage.cc
   ${TILEDB_CORE_INCLUDE_DIR}/tiledb/sm/query/readers/aggregators/count_aggregator.cc
-  ${TILEDB_CORE_INCLUDE_DIR}/tiledb/sm/query/readers/aggregators/mean_aggregator.cc
   ${TILEDB_CORE_INCLUDE_DIR}/tiledb/sm/query/readers/aggregators/min_max_aggregator.cc
   ${TILEDB_CORE_INCLUDE_DIR}/tiledb/sm/query/readers/aggregators/operation.cc
   ${TILEDB_CORE_INCLUDE_DIR}/tiledb/sm/query/readers/aggregators/output_buffer_validator.cc
diff --git a/tiledb/sm/query/query.h b/tiledb/sm/query/query.h
index 49fb0d9f7e37..54759f9d8c70 100644
--- a/tiledb/sm/query/query.h
+++ b/tiledb/sm/query/query.h
@@ -743,14 +743,6 @@ class Query {
     default_channel_aggregates_.emplace(output_field_name, aggregator);
   }
 
-  /**
-   * Get all aggregates from the default channel.
-   */
-  std::unordered_map<std::string, shared_ptr<IAggregator>>
-  get_default_channel_aggregates() {
-    return default_channel_aggregates_;
-  }
-
   /** Returns an aggregate based on the output field. */
   std::optional<shared_ptr<IAggregator>> get_aggregate(
       std::string output_field_name) const;
diff --git a/tiledb/sm/query/readers/aggregators/CMakeLists.txt b/tiledb/sm/query/readers/aggregators/CMakeLists.txt
index d4df7081b37b..291f96696252 100644
--- a/tiledb/sm/query/readers/aggregators/CMakeLists.txt
+++ b/tiledb/sm/query/readers/aggregators/CMakeLists.txt
@@ -31,7 +31,7 @@ include(object_library)
 # `aggregators` object library
 #
 commence(object_library aggregators)
-    this_target_sources(count_aggregator.cc mean_aggregator.cc min_max_aggregator.cc operation.cc output_buffer_validator.cc safe_sum.cc sum_aggregator.cc)
+    this_target_sources(count_aggregator.cc min_max_aggregator.cc operation.cc output_buffer_validator.cc safe_sum.cc sum_aggregator.cc)
     this_target_object_libraries(baseline array_schema)
 conclude(object_library)
 
diff --git a/tiledb/sm/query/readers/aggregators/aggregate_with_count.h b/tiledb/sm/query/readers/aggregators/aggregate_with_count.h
index 082d969767df..70ed41adccd5 100644
--- a/tiledb/sm/query/readers/aggregators/aggregate_with_count.h
+++ b/tiledb/sm/query/readers/aggregators/aggregate_with_count.h
@@ -28,8 +28,6 @@
  * @section DESCRIPTION
  *
  * This file defines class AggregateWithCount.
- *
- * TODO: Add more benchmark coverage for this class (sc-33758).
  */
 
 #ifndef TILEDB_AGGREGATE_WITH_COUNT_H
diff --git a/tiledb/sm/query/readers/aggregators/mean_aggregator.cc b/tiledb/sm/query/readers/aggregators/mean_aggregator.cc
deleted file mode 100644
index 4f4d845630b3..000000000000
--- a/tiledb/sm/query/readers/aggregators/mean_aggregator.cc
+++ /dev/null
@@ -1,153 +0,0 @@
-/**
- * @file mean_aggregator.cc
- *
- * @section LICENSE
- *
- * The MIT License
- *
- * @copyright Copyright (c) 2023 TileDB, Inc.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- *
- * @section DESCRIPTION
- *
- * This file implements class MeanAggregator.
- */
-
-#include "tiledb/sm/query/readers/aggregators/mean_aggregator.h"
-
-#include "tiledb/sm/query/query_buffer.h"
-#include "tiledb/sm/query/readers/aggregators/aggregate_buffer.h"
-
-namespace tiledb::sm {
-
-class MeanAggregatorStatusException : public StatusException {
- public:
-  explicit MeanAggregatorStatusException(const std::string& message)
-      : StatusException("MeanAggregator", message) {
-  }
-};
-
-template <typename T>
-MeanAggregator<T>::MeanAggregator(const FieldInfo field_info)
-    : OutputBufferValidator(field_info)
-    , field_info_(field_info)
-    , aggregate_with_count_(field_info)
-    , sum_(0)
-    , count_(0)
-    , validity_value_(
-          field_info_.is_nullable_ ? std::make_optional(0) : nullopt)
-    , sum_overflowed_(false) {
-  ensure_field_numeric(field_info_);
-}
-
-template <typename T>
-void MeanAggregator<T>::validate_output_buffer(
-    std::string output_field_name,
-    std::unordered_map<std::string, QueryBuffer>& buffers) {
-  if (buffers.count(output_field_name) == 0) {
-    throw MeanAggregatorStatusException("Result buffer doesn't exist.");
-  }
-
-  ensure_output_buffer_arithmetic(buffers[output_field_name]);
-}
-
-template <typename T>
-void MeanAggregator<T>::aggregate_data(AggregateBuffer& input_data) {
-  // TODO: While this could be shared with the sum implementation, it isn't
-  // because it will be improved soon... Means should always be able to be
-  // computed with no overflows. The simple formula is 2*(a/2 + b/2) + a%2 +
-  // b%2, but we need benchmarks to see what the performance hit would be to run
-  // this more complex formula (sc-32789).
-
-  // Return if a previous aggregation has overflowed.
-  if (sum_overflowed_) {
-    return;
-  }
-
-  try {
-    tuple<typename sum_type_data<T>::sum_type, uint64_t> res;
-
-    // TODO: This is duplicated across aggregates but will go away with
-    // sc-33104.
-    if (input_data.is_count_bitmap()) {
-      res = aggregate_with_count_.template aggregate<uint64_t>(input_data);
-    } else {
-      res = aggregate_with_count_.template aggregate<uint8_t>(input_data);
-    }
-
-    const auto value = std::get<0>(res);
-    const auto count = std::get<1>(res);
-    SafeSum().safe_sum(value, sum_);
-    count_ += count;
-
-    // Here we know that if the count is greater than 0, it means at least one
-    // valid item was found, which means the result is valid.
-    if (field_info_.is_nullable_ && count) {
-      validity_value_ = 1;
-    }
-  } catch (std::overflow_error& e) {
-    sum_overflowed_ = true;
-  }
-}
-
-template <typename T>
-void MeanAggregator<T>::copy_to_user_buffer(
-    std::string output_field_name,
-    std::unordered_map<std::string, QueryBuffer>& buffers) {
-  auto& result_buffer = buffers[output_field_name];
-  auto s = static_cast<double*>(result_buffer.buffer_);
-
-  if (sum_overflowed_) {
-    *s = std::numeric_limits<double>::max();
-  } else {
-    *s = static_cast<double>(sum_) / count_;
-  }
-
-  if (result_buffer.buffer_size_) {
-    *result_buffer.buffer_size_ = sizeof(double);
-  }
-
-  if (field_info_.is_nullable_) {
-    auto v = static_cast<uint8_t*>(result_buffer.validity_vector_.buffer());
-    if (sum_overflowed_) {
-      *v = 0;
-    } else {
-      *v = validity_value_.value();
-    }
-
-    if (result_buffer.validity_vector_.buffer_size()) {
-      *result_buffer.validity_vector_.buffer_size() = 1;
-    }
-  }
-}
-
-// Explicit template instantiations
-template MeanAggregator<int8_t>::MeanAggregator(const FieldInfo);
-template MeanAggregator<int16_t>::MeanAggregator(const FieldInfo);
-template MeanAggregator<int32_t>::MeanAggregator(const FieldInfo);
-template MeanAggregator<int64_t>::MeanAggregator(const FieldInfo);
-template MeanAggregator<uint8_t>::MeanAggregator(const FieldInfo);
-template MeanAggregator<uint16_t>::MeanAggregator(const FieldInfo);
-template MeanAggregator<uint32_t>::MeanAggregator(const FieldInfo);
-template MeanAggregator<uint64_t>::MeanAggregator(const FieldInfo);
-template MeanAggregator<float>::MeanAggregator(const FieldInfo);
-template MeanAggregator<double>::MeanAggregator(const FieldInfo);
-
-}  // namespace tiledb::sm
diff --git a/tiledb/sm/query/readers/aggregators/mean_aggregator.h b/tiledb/sm/query/readers/aggregators/mean_aggregator.h
deleted file mode 100644
index 96e38504188e..000000000000
--- a/tiledb/sm/query/readers/aggregators/mean_aggregator.h
+++ /dev/null
@@ -1,157 +0,0 @@
-/**
- * @file   mean_aggregator.h
- *
- * @section LICENSE
- *
- * The MIT License
- *
- * @copyright Copyright (c) 2023 TileDB, Inc.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- *
- * @section DESCRIPTION
- *
- * This file defines class MeanAggregator.
- */
-
-#ifndef TILEDB_MEAN_AGGREGATOR_H
-#define TILEDB_MEAN_AGGREGATOR_H
-
-#include "tiledb/common/common.h"
-#include "tiledb/sm/query/readers/aggregators/aggregate_with_count.h"
-#include "tiledb/sm/query/readers/aggregators/field_info.h"
-#include "tiledb/sm/query/readers/aggregators/iaggregator.h"
-#include "tiledb/sm/query/readers/aggregators/safe_sum.h"
-#include "tiledb/sm/query/readers/aggregators/sum_type.h"
-#include "tiledb/sm/query/readers/aggregators/validity_policies.h"
-
-namespace tiledb::sm {
-
-class QueryBuffer;
-
-template <typename T>
-class MeanAggregator : public InputFieldValidator,
-                       public OutputBufferValidator,
-                       public IAggregator {
- public:
-  /* ********************************* */
-  /*     CONSTRUCTORS & DESTRUCTORS    */
-  /* ********************************* */
-
-  MeanAggregator() = delete;
-
-  /**
-   * Constructor.
-   *
-   * @param field_info Field info.
-   */
-  MeanAggregator(FieldInfo field_info);
-
-  DISABLE_COPY_AND_COPY_ASSIGN(MeanAggregator);
-  DISABLE_MOVE_AND_MOVE_ASSIGN(MeanAggregator);
-
-  /* ********************************* */
-  /*                API                */
-  /* ********************************* */
-
-  /** Returns the field name for the aggregator. */
-  std::string field_name() override {
-    return field_info_.name_;
-  }
-
-  /** Returns if the aggregation is var sized or not. */
-  bool aggregation_var_sized() override {
-    return false;
-  };
-
-  /** Returns if the aggregation is nullable or not. */
-  bool aggregation_nullable() override {
-    return field_info_.is_nullable_;
-  }
-
-  /** Returns if the aggregate needs to be recomputed on overflow. */
-  bool need_recompute_on_overflow() override {
-    return true;
-  }
-
-  /**
-   * Validate the result buffer.
-   *
-   * @param output_field_name Name for the output buffer.
-   * @param buffers Query buffers.
-   */
-  void validate_output_buffer(
-      std::string output_field_name,
-      std::unordered_map<std::string, QueryBuffer>& buffers) override;
-
-  /**
-   * Aggregate data using the aggregator.
-   *
-   * @param input_data Input data for aggregation.
-   */
-  void aggregate_data(AggregateBuffer& input_data) override;
-
-  /**
-   * Copy final data to the user buffer.
-   *
-   * @param output_field_name Name for the output buffer.
-   * @param buffers Query buffers.
-   */
-  void copy_to_user_buffer(
-      std::string output_field_name,
-      std::unordered_map<std::string, QueryBuffer>& buffers) override;
-
-  /** Returns name of the aggregate. */
-  std::string aggregate_name() override {
-    return constants::aggregate_mean_str;
-  }
-
-  /** Returns the TileDB datatype of the output field for the aggregate. */
-  Datatype output_datatype() override {
-    return Datatype::FLOAT64;
-  }
-
- private:
-  /* ********************************* */
-  /*         PRIVATE ATTRIBUTES        */
-  /* ********************************* */
-
-  /** Field information. */
-  const FieldInfo field_info_;
-
-  /** AggregateWithCount to do summation of AggregateBuffer data. */
-  AggregateWithCount<T, typename sum_type_data<T>::sum_type, SafeSum, NonNull>
-      aggregate_with_count_;
-
-  /** Computed sum. */
-  std::atomic<typename sum_type_data<T>::sum_type> sum_;
-
-  /** Count of values. */
-  std::atomic<uint64_t> count_;
-
-  /** Computed validity value. */
-  optional<uint8_t> validity_value_;
-
-  /** Has the sum overflowed. */
-  std::atomic<bool> sum_overflowed_;
-};
-
-}  // namespace tiledb::sm
-
-#endif  // TILEDB_MEAN_AGGREGATOR_H
diff --git a/tiledb/sm/query/readers/aggregators/safe_sum.cc b/tiledb/sm/query/readers/aggregators/safe_sum.cc
index ea74f2bfd515..e1f09924dfca 100644
--- a/tiledb/sm/query/readers/aggregators/safe_sum.cc
+++ b/tiledb/sm/query/readers/aggregators/safe_sum.cc
@@ -28,8 +28,6 @@
  * @section DESCRIPTION
  *
  * This file implements class SafeSum.
- *
- * TODO: Testing for this class is not done (sc-33762).
  */
 
 #include "tiledb/sm/query/readers/aggregators/safe_sum.h"
diff --git a/tiledb/sm/query/readers/aggregators/sum_aggregator.cc b/tiledb/sm/query/readers/aggregators/sum_aggregator.cc
index 53a0384fc8ac..21cb3647eb73 100644
--- a/tiledb/sm/query/readers/aggregators/sum_aggregator.cc
+++ b/tiledb/sm/query/readers/aggregators/sum_aggregator.cc
@@ -45,7 +45,7 @@ class SumAggregatorStatusException : public StatusException {
 };
 
 template <typename T>
-SumAggregator<T>::SumAggregator(const FieldInfo field_info)
+SumWithCountAggregator<T>::SumWithCountAggregator(const FieldInfo field_info)
     : OutputBufferValidator(field_info)
     , field_info_(field_info)
     , aggregate_with_count_(field_info)
@@ -57,7 +57,7 @@ SumAggregator<T>::SumAggregator(const FieldInfo field_info)
 }
 
 template <typename T>
-void SumAggregator<T>::validate_output_buffer(
+void SumWithCountAggregator<T>::validate_output_buffer(
     std::string output_field_name,
     std::unordered_map<std::string, QueryBuffer>& buffers) {
   if (buffers.count(output_field_name) == 0) {
@@ -68,7 +68,7 @@ void SumAggregator<T>::validate_output_buffer(
 }
 
 template <typename T>
-void SumAggregator<T>::aggregate_data(AggregateBuffer& input_data) {
+void SumWithCountAggregator<T>::aggregate_data(AggregateBuffer& input_data) {
   // Return if a previous aggregation has overflowed.
   if (sum_overflowed_) {
     return;
@@ -76,9 +76,6 @@ void SumAggregator<T>::aggregate_data(AggregateBuffer& input_data) {
 
   try {
     tuple<typename sum_type_data<T>::sum_type, uint64_t> res;
-
-    // TODO: This is duplicated across aggregates but will go away with
-    // sc-33104.
     if (input_data.is_count_bitmap()) {
       res = aggregate_with_count_.template aggregate<uint64_t>(input_data);
     } else {
@@ -88,6 +85,7 @@ void SumAggregator<T>::aggregate_data(AggregateBuffer& input_data) {
     const auto value = std::get<0>(res);
     const auto count = std::get<1>(res);
     SafeSum().safe_sum(value, sum_);
+    count_ += count;
 
     // Here we know that if the count is greater than 0, it means at least one
     // valid item was found, which means the result is valid.
@@ -99,6 +97,23 @@ void SumAggregator<T>::aggregate_data(AggregateBuffer& input_data) {
   }
 }
 
+template <typename T>
+void SumWithCountAggregator<T>::copy_validity_value_to_user_buffers(
+    QueryBuffer& result_buffer) {
+  if (field_info_.is_nullable_) {
+    auto v = static_cast<uint8_t*>(result_buffer.validity_vector_.buffer());
+    if (sum_overflowed_) {
+      *v = 0;
+    } else {
+      *v = validity_value_.value();
+    }
+
+    if (result_buffer.validity_vector_.buffer_size()) {
+      *result_buffer.validity_vector_.buffer_size() = 1;
+    }
+  }
+}
+
 template <typename T>
 void SumAggregator<T>::copy_to_user_buffer(
     std::string output_field_name,
@@ -106,31 +121,61 @@ void SumAggregator<T>::copy_to_user_buffer(
   auto& result_buffer = buffers[output_field_name];
   auto s =
       static_cast<typename sum_type_data<T>::sum_type*>(result_buffer.buffer_);
-  if (sum_overflowed_) {
+  if (SumWithCountAggregator<T>::sum_overflowed_) {
     *s = std::numeric_limits<typename sum_type_data<T>::sum_type>::max();
   } else {
-    *s = sum_;
+    *s = SumWithCountAggregator<T>::sum_;
   }
 
   if (result_buffer.buffer_size_) {
     *result_buffer.buffer_size_ = sizeof(typename sum_type_data<T>::sum_type);
   }
 
-  if (field_info_.is_nullable_) {
-    auto v = static_cast<uint8_t*>(result_buffer.validity_vector_.buffer());
-    if (sum_overflowed_) {
-      *v = 0;
-    } else {
-      *v = validity_value_.value();
-    }
+  SumWithCountAggregator<T>::copy_validity_value_to_user_buffers(result_buffer);
+}
 
-    if (result_buffer.validity_vector_.buffer_size()) {
-      *result_buffer.validity_vector_.buffer_size() = 1;
-    }
+template <typename T>
+void MeanAggregator<T>::copy_to_user_buffer(
+    std::string output_field_name,
+    std::unordered_map<std::string, QueryBuffer>& buffers) {
+  auto& result_buffer = buffers[output_field_name];
+  auto s = static_cast<double*>(result_buffer.buffer_);
+
+  if (SumWithCountAggregator<T>::sum_overflowed_) {
+    *s = std::numeric_limits<double>::max();
+  } else {
+    *s = static_cast<double>(SumWithCountAggregator<T>::sum_) /
+         SumWithCountAggregator<T>::count_;
+  }
+
+  if (result_buffer.buffer_size_) {
+    *result_buffer.buffer_size_ = sizeof(double);
   }
+
+  SumWithCountAggregator<T>::copy_validity_value_to_user_buffers(result_buffer);
 }
 
 // Explicit template instantiations
+template SumWithCountAggregator<int8_t>::SumWithCountAggregator(
+    const FieldInfo);
+template SumWithCountAggregator<int16_t>::SumWithCountAggregator(
+    const FieldInfo);
+template SumWithCountAggregator<int32_t>::SumWithCountAggregator(
+    const FieldInfo);
+template SumWithCountAggregator<int64_t>::SumWithCountAggregator(
+    const FieldInfo);
+template SumWithCountAggregator<uint8_t>::SumWithCountAggregator(
+    const FieldInfo);
+template SumWithCountAggregator<uint16_t>::SumWithCountAggregator(
+    const FieldInfo);
+template SumWithCountAggregator<uint32_t>::SumWithCountAggregator(
+    const FieldInfo);
+template SumWithCountAggregator<uint64_t>::SumWithCountAggregator(
+    const FieldInfo);
+template SumWithCountAggregator<float>::SumWithCountAggregator(const FieldInfo);
+template SumWithCountAggregator<double>::SumWithCountAggregator(
+    const FieldInfo);
+
 template SumAggregator<int8_t>::SumAggregator(const FieldInfo);
 template SumAggregator<int16_t>::SumAggregator(const FieldInfo);
 template SumAggregator<int32_t>::SumAggregator(const FieldInfo);
@@ -142,4 +187,15 @@ template SumAggregator<uint64_t>::SumAggregator(const FieldInfo);
 template SumAggregator<float>::SumAggregator(const FieldInfo);
 template SumAggregator<double>::SumAggregator(const FieldInfo);
 
+template MeanAggregator<int8_t>::MeanAggregator(const FieldInfo);
+template MeanAggregator<int16_t>::MeanAggregator(const FieldInfo);
+template MeanAggregator<int32_t>::MeanAggregator(const FieldInfo);
+template MeanAggregator<int64_t>::MeanAggregator(const FieldInfo);
+template MeanAggregator<uint8_t>::MeanAggregator(const FieldInfo);
+template MeanAggregator<uint16_t>::MeanAggregator(const FieldInfo);
+template MeanAggregator<uint32_t>::MeanAggregator(const FieldInfo);
+template MeanAggregator<uint64_t>::MeanAggregator(const FieldInfo);
+template MeanAggregator<float>::MeanAggregator(const FieldInfo);
+template MeanAggregator<double>::MeanAggregator(const FieldInfo);
+
 }  // namespace tiledb::sm
diff --git a/tiledb/sm/query/readers/aggregators/sum_aggregator.h b/tiledb/sm/query/readers/aggregators/sum_aggregator.h
index 0088f50fc389..14b5316e1c3d 100644
--- a/tiledb/sm/query/readers/aggregators/sum_aggregator.h
+++ b/tiledb/sm/query/readers/aggregators/sum_aggregator.h
@@ -45,25 +45,25 @@ namespace tiledb::sm {
 class QueryBuffer;
 
 template <typename T>
-class SumAggregator : public InputFieldValidator,
-                      public OutputBufferValidator,
-                      public IAggregator {
+class SumWithCountAggregator : public InputFieldValidator,
+                               public OutputBufferValidator,
+                               public IAggregator {
  public:
   /* ********************************* */
   /*     CONSTRUCTORS & DESTRUCTORS    */
   /* ********************************* */
 
-  SumAggregator() = delete;
+  SumWithCountAggregator() = delete;
 
   /**
    * Constructor.
    *
    * @param field_info Field info.
    */
-  SumAggregator(FieldInfo field_info);
+  SumWithCountAggregator(FieldInfo field_info);
 
-  DISABLE_COPY_AND_COPY_ASSIGN(SumAggregator);
-  DISABLE_MOVE_AND_MOVE_ASSIGN(SumAggregator);
+  DISABLE_COPY_AND_COPY_ASSIGN(SumWithCountAggregator);
+  DISABLE_MOVE_AND_MOVE_ASSIGN(SumWithCountAggregator);
 
   /* ********************************* */
   /*                API                */
@@ -106,6 +106,60 @@ class SumAggregator : public InputFieldValidator,
    */
   void aggregate_data(AggregateBuffer& input_data) override;
 
+  /**
+   * Copy final validity value to the user buffer.
+   *
+   * @param result_buffer Query buffer to copy to.
+   */
+  void copy_validity_value_to_user_buffers(QueryBuffer& result_buffer);
+
+ protected:
+  /* ********************************* */
+  /*        PROTECTED ATTRIBUTES       */
+  /* ********************************* */
+
+  /** Field information. */
+  const FieldInfo field_info_;
+
+  /** AggregateWithCount to do summation of AggregateBuffer data. */
+  AggregateWithCount<T, typename sum_type_data<T>::sum_type, SafeSum, NonNull>
+      aggregate_with_count_;
+
+  /** Computed sum. */
+  std::atomic<typename sum_type_data<T>::sum_type> sum_;
+
+  /** Count of values. */
+  std::atomic<uint64_t> count_;
+
+  /** Computed validity value. */
+  optional<uint8_t> validity_value_;
+
+  /** Has the sum overflowed. */
+  std::atomic<bool> sum_overflowed_;
+};
+
+template <typename T>
+class SumAggregator : public SumWithCountAggregator<T> {
+ public:
+  /* ********************************* */
+  /*     CONSTRUCTORS & DESTRUCTORS    */
+  /* ********************************* */
+
+  SumAggregator() = delete;
+
+  /**
+   * Constructor.
+   *
+   * @param field_info Field info.
+   */
+  SumAggregator(FieldInfo field_info)
+      : SumWithCountAggregator<T>(field_info) {
+  }
+
+  /* ********************************* */
+  /*                API                */
+  /* ********************************* */
+
   /**
    * Copy final data to the user buffer.
    *
@@ -125,27 +179,48 @@ class SumAggregator : public InputFieldValidator,
   Datatype output_datatype() override {
     return sum_type_data<T>::tiledb_datatype;
   }
+};
 
- private:
+template <typename T>
+class MeanAggregator : public SumWithCountAggregator<T> {
+ public:
   /* ********************************* */
-  /*         PRIVATE ATTRIBUTES        */
+  /*     CONSTRUCTORS & DESTRUCTORS    */
   /* ********************************* */
 
-  /** Field information. */
-  const FieldInfo field_info_;
+  MeanAggregator() = delete;
 
-  /** AggregateWithCount to do summation of AggregateBuffer data. */
-  AggregateWithCount<T, typename sum_type_data<T>::sum_type, SafeSum, NonNull>
-      aggregate_with_count_;
+  /**
+   * Constructor.
+   *
+   * @param field_info Field info.
+   */
+  MeanAggregator(FieldInfo field_info)
+      : SumWithCountAggregator<T>(field_info) {
+  }
 
-  /** Computed sum. */
-  std::atomic<typename sum_type_data<T>::sum_type> sum_;
+  /* ********************************* */
+  /*                API                */
+  /* ********************************* */
+  /**
+   * Copy final data to the user buffer.
+   *
+   * @param output_field_name Name for the output buffer.
+   * @param buffers Query buffers.
+   */
+  void copy_to_user_buffer(
+      std::string output_field_name,
+      std::unordered_map<std::string, QueryBuffer>& buffers) override;
 
-  /** Computed validity value. */
-  optional<uint8_t> validity_value_;
+  /** Returns name of the aggregate, e.g. COUNT, MIN, SUM. */
+  std::string aggregate_name() override {
+    return constants::aggregate_mean_str;
+  }
 
-  /** Has the sum overflowed. */
-  std::atomic<bool> sum_overflowed_;
+  /** Returns the TileDB datatype of the output field for the aggregate. */
+  Datatype output_datatype() override {
+    return Datatype::FLOAT64;
+  }
 };
 
 }  // namespace tiledb::sm
diff --git a/tiledb/sm/query/readers/aggregators/sum_type.h b/tiledb/sm/query/readers/aggregators/sum_type.h
index ed2b77a0a682..11cf1403c8bb 100644
--- a/tiledb/sm/query/readers/aggregators/sum_type.h
+++ b/tiledb/sm/query/readers/aggregators/sum_type.h
@@ -28,8 +28,6 @@
  * @section DESCRIPTION
  *
  * This file defines sum types in relation to basic types.
- *
- * TODO: This needs to be improved to remove macros (sc-33764).
  */
 
 #ifndef TILEDB_SUM_TYPE_H
diff --git a/tiledb/sm/query/readers/aggregators/test/unit_aggregators.cc b/tiledb/sm/query/readers/aggregators/test/unit_aggregators.cc
index 354f89056525..f4fdd0538562 100644
--- a/tiledb/sm/query/readers/aggregators/test/unit_aggregators.cc
+++ b/tiledb/sm/query/readers/aggregators/test/unit_aggregators.cc
@@ -34,7 +34,6 @@
 #include "tiledb/sm/query/query_buffer.h"
 #include "tiledb/sm/query/readers/aggregators/aggregate_buffer.h"
 #include "tiledb/sm/query/readers/aggregators/count_aggregator.h"
-#include "tiledb/sm/query/readers/aggregators/mean_aggregator.h"
 #include "tiledb/sm/query/readers/aggregators/min_max_aggregator.h"
 #include "tiledb/sm/query/readers/aggregators/sum_aggregator.h"