diff --git a/source/reference/read-concern-local.txt b/source/reference/read-concern-local.txt
index 96be6feaef9..cab1ad33b10 100644
--- a/source/reference/read-concern-local.txt
+++ b/source/reference/read-concern-local.txt
@@ -9,8 +9,8 @@ Read Concern ``"local"``
 ========================
 
 .. meta::
-   :description: read concern, local read concern, read isolation
-   :keywords: read concern, local read concern, read isolation
+   :description: read concern, local read concern, read isolation, transactions, multi-document transactions
+   :keywords: read concern, local read concern, read isolation, transactions, multi-document transactions
 
 
 A query with read concern ``"local"`` returns the instance's most
@@ -33,6 +33,40 @@ Causally Consistent Sessions
 Read concern :readconcern:`local` is available for use with causally
 consistent sessions.
 
+Read Concern ``"local"`` and Transactions
+--------------------------------------------
+
+In a multi-document transaction, read concern levels
+:readconcern:`"local"` and :readconcern:`"snapshot"` are available for
+:ref:`read and write operations that support read concern in a
+transaction <read-concern-operations>`.
+
+.. note::
+
+   For the operations in a transaction, you set the read concern at the
+   transaction level, not at the individual operation level.
+
+.. seealso:: :readconcern:`"snapshot"`
+
+Write Operations and Read Concern ``"local"``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+In a multi-document transaction, both the read operations and the write
+operations can accept the read concern level :readconcern:`"local"`.
+The following write operations can accept a read concern level as part
+of a transaction:
+
+- :dbcommand:`delete`
+
+- :dbcommand:`findAndModify`
+
+- :dbcommand:`insert`
+
+- :dbcommand:`update`
+
+For a list of all operations that accept read concerns, see
+:ref:`read-concern-operations`.
+
 Example
 -------
 
diff --git a/source/reference/read-concern-snapshot.txt b/source/reference/read-concern-snapshot.txt
new file mode 100644
index 00000000000..fcaf5f55232
--- /dev/null
+++ b/source/reference/read-concern-snapshot.txt
@@ -0,0 +1,75 @@
+.. default-domain:: mongodb
+
+.. class:: hidden
+
+   .. readconcern:: "snapshot"
+
+===========================
+Read Concern ``"snapshot"``
+===========================
+
+.. meta::
+   :description: read concern, snapshot read concern, read isolation, transactions, multi-document transactions
+   :keywords: read concern, snapshot read concern, read isolation, transactions, multi-document transactions
+
+.. versionadded:: 4.0
+
+Read concern ``"snapshot"`` is only available for multi-document
+transactions.
+
+- If the transaction is not part of a :ref:`causally consistent session
+  <sessions>`, operations with read concern ``"snapshot"`` reads data
+  from a snapshot of the most recent majority committed data at
+  transaction start.
+
+- If the transaction is part of a :ref:`causally consistent session
+  <sessions>`, operations with read concern ``"snapshot"`` reads data
+  from a snapshot of the first majority committed data that guarantees
+  causal consistency with the operation immediately prior to the
+  transaction start. The time of the snapshot may be after the
+  transaction start to guarantee causal consistency.
+
+Read Concern ``"snapshot"`` and Transactions
+--------------------------------------------
+
+In a multi-document transaction, read concern levels
+:readconcern:`"local"` and :readconcern:`"snapshot"` are available for
+:ref:`read and write operations that support read concern in a
+transaction <read-concern-operations>`.
+
+.. note::
+
+   For the operations in a transaction, you set the read concern at the
+   transaction level, not at the individual operation level.
+
+.. seealso:: :readconcern:`"local"`
+
+Write Operations and Read Concern ``"snapshot"``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+In a multi-document transaction, both the read operations and the write
+operations can accept the read concern level :readconcern:`"snapshot"`.
+The following write operations can accept a read concern level as part
+of a transaction:
+
+- :dbcommand:`delete`
+
+- :dbcommand:`findAndModify`
+
+- :dbcommand:`insert`
+
+- :dbcommand:`update`
+
+For a list of all operations that accept read concerns, see
+:ref:`read-concern-operations`.
+
+Causally Consistent Sessions
+----------------------------
+
+:readconcern:`snapshot` is available for transactions that are part of
+a causally consistent session.
+
+If the transaction is part of a :ref:`causally consistent session
+<sessions>`, the snapshot of the majority committed data reflects the
+earliest time from the transaction start time(inclusive) that
+guarantees causally consistency with the prior operation in the session.
diff --git a/source/reference/read-concern.txt b/source/reference/read-concern.txt
index bd567acad98..d9d78b74c65 100644
--- a/source/reference/read-concern.txt
+++ b/source/reference/read-concern.txt
@@ -132,6 +132,26 @@ The following read concern levels are available:
        For more information, see the :readconcern:`"linearizable"`
        reference page.
 
+   * - :readconcern:`"snapshot"`
+
+     -  Only available for operations within multi-document transactions.
+
+        - If the transaction is not part of a :ref:`causally consistent session
+          <sessions>`, operations with read concern ``"snapshot"`` read data
+          from a snapshot of the most recent majority committed data at
+          transaction start.
+
+        - If the transaction is part of a :ref:`causally consistent session
+          <sessions>`, operations with read concern ``"snapshot"`` reads data
+          from a snapshot of the first majority committed data that guarantees
+          causal consistency with the operation immediately prior to the
+          transaction start. The time of the snapshot may be after the
+          transaction start to guarantee causal consistency.
+        
+        Read concern :readconcern:`snapshot` is available for
+        multi-document transactions associated with causally consistent
+        sessions.
+
 .. include:: /includes/fact-readConcern-most-recent-data-in-node.rst
 
 For more information on each read concern level, see:
@@ -143,55 +163,190 @@ For more information on each read concern level, see:
    /reference/read-concern-available
    /reference/read-concern-majority
    /reference/read-concern-linearizable
+   /reference/read-concern-snapshot
+
+.. _read-concern-operations:
+
+``readConcern`` Support
+-----------------------
 
-``readConcern`` Syntax
-----------------------
 
-You can specify a ``readConcern`` level [#after-cluster-time]_ as an
-option:
+You can specify a ``readConcern`` level as an option to commands and
+methods that support read concern:
 
 .. code-block:: javascript
 
-   readConcern: { level: <"majority"|"local"|"linearizable"|"available"> }
+   readConcern: { level: <level> }
 
-.. note::
+To specify the read concern level for the :binary:`~bin.mongo` shell
+method :method:`db.collection.find()`, use the
+:method:`cursor.readConcern()` method:
 
-   For operations in :ref:`causally consistent sessions
-   <causal-consistency>`, only :readconcern:`"local"` and
-   :readconcern:`"majority"` levels are available.
-   
-The following operations support the ``readConcern`` option:
+.. code-block:: javascript
 
-- :dbcommand:`find` command
+   db.collection.find().readConcern(<level>)
 
-- :dbcommand:`aggregate` command and the
-  :method:`db.collection.aggregate()` method
+The following operations support read concern:
 
-- :dbcommand:`distinct` command
+.. note::
 
-- :dbcommand:`count` command
+   - For operations in a multi-document transaction, read concern
+     levels :readconcern:`"local"` and :readconcern:`"snapshot"` are
+     available. Read concern level :readconcern:`"snapshot"` is only
+     available for operations in a multi-document transaction.
 
-- :dbcommand:`parallelCollectionScan` command
+   - Write commands that are part of a multi-document transaction can
+     support read concern of either :readconcern:`"local"` or
+     :readconcern:`"snapshot"`.
 
-- :dbcommand:`geoNear` command
+   - For operations in a :ref:`causally consistent session
+     <causal-consistency>`, :readconcern:`"local"` and
+     :readconcern:`"majority"` levels are available. If a
+     multi-document transaction is associated with a causally
+     consistent session, :readconcern:`"snapshot"` is also available for
+     the operations in the transaction.
 
-- :dbcommand:`geoSearch` command
+.. important::
 
-- :dbcommand:`group` command
+   To set read concern for operations in a transaction, you set the
+   read concern at the transaction level, not at the individual
+   operation level.
 
-To specify the read concern level for the :binary:`~bin.mongo` shell method
-:method:`db.collection.find()`, use the :method:`cursor.readConcern()`
-method:
+.. list-table::
+   :header-rows: 1
 
-.. code-block:: javascript
+   * - Operation
+     - :readconcern:`"local"`
+     - :readconcern:`"available"`
+     - :readconcern:`"majority"` 
+     - :readconcern:`"snapshot"`
+     - :readconcern:`"linearizable"`
+
+   * - :dbcommand:`count`
+     - |checkmark|
+     - |checkmark|
+     - |checkmark|
+     - |checkmark|
+     - |checkmark|
+
+   * - :dbcommand:`distinct`
+
+     - |checkmark|
+     - |checkmark|
+     - |checkmark|
+     - |checkmark|
+     - |checkmark|
+
+
+   * - :dbcommand:`find`
+     - |checkmark|
+     - |checkmark|
+     - |checkmark|
+     - |checkmark|
+     - |checkmark|
+
+   * - :method:`db.collection.find()` 
+       shell method using
+       :method:`cursor.readConcern()`
+
+     - |checkmark|
+     - |checkmark|
+     - |checkmark|
+     - |checkmark|
+     - |checkmark|
+
+   * - :dbcommand:`geoNear`
+     - |checkmark|
+     - |checkmark|
+     - |checkmark|
+     - 
+     - |checkmark|
+
+   * - :dbcommand:`geoSearch`
+     - |checkmark|
+     - |checkmark|
+     - |checkmark|
+     - |checkmark|
+     - |checkmark|
+
+   * - :dbcommand:`getMore`
+     - |checkmark|
+     - 
+     - 
+     - 
+     - |checkmark|
+
+   * - :dbcommand:`group`
+     - |checkmark|
+     - |checkmark|
+     - |checkmark|
+     - 
+     - |checkmark|
+
+   * - :dbcommand:`aggregate`
+       :method:`db.collection.aggregate()` shell method
+
+       *Only when against a collection, not a view.*
+
+     - |checkmark|
+     - |checkmark|
+     - |checkmark|
+     - |checkmark|
+     - |checkmark|
+
+   * - :dbcommand:`parallelCollectionScan`
+     - |checkmark|
+     - |checkmark|
+     - |checkmark|
+     - 
+     - |checkmark|
+
+The following write operations can also accept a read concern if part
+of a multi-document transaction:
 
-   db.collection.find().readConcern(<"majority"|"local"|"linearizable"|"available">)
+.. important::
 
-.. [#after-cluster-time]
+   To set read concern for operations in a transaction, you set the
+   read concern at the transaction level, not at the individual
+   operation level.
 
-   For :ref:`causally consistent sessions <causal-consistency>`,
-   MongoDB drivers automatically specifies the :ref:`afterClusterTime
-   <afterClusterTime>` value in the read concern.
+.. list-table::
+   :header-rows: 1
+
+   * - Command
+     - :readconcern:`"local"`
+     - :readconcern:`"available"`
+     - :readconcern:`"majority"`
+     - :readconcern:`"snapshot"`
+     - :readconcern:`"linearizable"`
+
+   * - :dbcommand:`delete`
+     - |checkmark|
+     - 
+     - 
+     - |checkmark| 
+     - 
+
+   * - :dbcommand:`findAndModify`
+     - |checkmark|
+     - 
+     - 
+     - |checkmark| 
+     - 
+
+   * - :dbcommand:`insert`
+     - |checkmark| 
+     - 
+     - 
+     - |checkmark| 
+     - 
+
+   * - :dbcommand:`update`
+     - |checkmark| 
+     - 
+     - 
+     - |checkmark|
+     - 
 
 Considerations
 --------------
@@ -258,20 +413,12 @@ session, MongoDB 3.6 introduces the ``afterClusterTime`` read concern
 option to be set automatically by the drivers for operations associated
 with causally consistent sessions.
 
-The ``afterClusterTime`` read concern option is available for
-:readconcern:`"local"` and :readconcern:`"majority"` read
-concern levels:
-
 .. important::
 
    Do not manually set ``afterClusterTime``. MongoDB drivers set
    this value automatically for operations associated with
    causally consistent sessions.
 
-.. code-block:: javascript
-
-   readConcern: { level: <"majority"|"local"> , afterClusterTime: <Timestamp> }
-
 To satisfy a read request with an ``afterClusterTime`` value of ``T``,
 a :binary:`~bin.mongod` must perform the request after its oplog
 reaches time ``T``. If its oplog has not reached time ``T``, the
@@ -283,3 +430,5 @@ requirement and the specified ``afterClusterTime`` requirement.
 
 For read operations not associated with causally consistent sessions,
 ``afterClusterTime`` is unset.
+
+.. include:: /includes/unicode-checkmark.rst