diff --git a/lib/code_corps/messages/conversation_parts.ex b/lib/code_corps/messages/conversation_parts.ex
index 3d1b047a5..75ac32182 100644
--- a/lib/code_corps/messages/conversation_parts.ex
+++ b/lib/code_corps/messages/conversation_parts.ex
@@ -4,7 +4,8 @@ defmodule CodeCorps.Messages.ConversationParts do
   i.e. a reply to the `CodeCorps.Conversation` by any participant.
   """
 
-  import Ecto.Changeset, only: [assoc_constraint: 2, cast: 3, validate_required: 2]
+  import Ecto.Changeset, only: [assoc_constraint: 2, cast: 3, validate_required: 2,
+                                validate_inclusion: 3]
 
   alias CodeCorps.{
     ConversationPart,
@@ -24,9 +25,14 @@ defmodule CodeCorps.Messages.ConversationParts do
   @spec create_changeset(ConversationPart.t, map) :: Ecto.Changeset.t
   def create_changeset(%ConversationPart{} = conversation_part, attrs) do
     conversation_part
-    |> cast(attrs, [:author_id, :body, :conversation_id])
+    |> cast(attrs, [:author_id, :body, :part_type, :conversation_id])
     |> validate_required([:author_id, :body, :conversation_id])
+    |> validate_inclusion(:part_type, part_types())
     |> assoc_constraint(:author)
     |> assoc_constraint(:conversation)
   end
+
+  defp part_types do
+    ~w{ comment note reopened closed }
+  end
 end
diff --git a/lib/code_corps/model/conversation_part.ex b/lib/code_corps/model/conversation_part.ex
index 02e92cd85..0520f4100 100644
--- a/lib/code_corps/model/conversation_part.ex
+++ b/lib/code_corps/model/conversation_part.ex
@@ -19,6 +19,7 @@ defmodule CodeCorps.ConversationPart do
   schema "conversation_parts" do
     field :body, :string, null: false
     field :read_at, :utc_datetime, null: true
+    field :part_type, :string
 
     belongs_to :author, CodeCorps.User
     belongs_to :conversation, CodeCorps.Conversation
diff --git a/priv/repo/migrations/20171220154922_add_part_type_to_conversation.exs b/priv/repo/migrations/20171220154922_add_part_type_to_conversation.exs
new file mode 100644
index 000000000..4ea3f639d
--- /dev/null
+++ b/priv/repo/migrations/20171220154922_add_part_type_to_conversation.exs
@@ -0,0 +1,9 @@
+defmodule CodeCorps.Repo.Migrations.AddPartTypeToConversation do
+  use Ecto.Migration
+
+  def change do
+    alter table(:conversation_parts) do
+      add :part_type, :string
+    end
+  end
+end
diff --git a/test/lib/code_corps/messages/conversation_parts_test.exs b/test/lib/code_corps/messages/conversation_parts_test.exs
index 947e20493..7008edfc2 100644
--- a/test/lib/code_corps/messages/conversation_parts_test.exs
+++ b/test/lib/code_corps/messages/conversation_parts_test.exs
@@ -8,7 +8,8 @@ defmodule CodeCorps.Messages.ConversationPartsTest do
   }
 
   @valid_attrs %{
-    body: "Test body."
+    body: "Test body.",
+    part_type: "comment"
   }
 
   describe "create_changeset/2" do
@@ -16,6 +17,33 @@ defmodule CodeCorps.Messages.ConversationPartsTest do
       attrs = @valid_attrs |> Map.merge(%{author_id: 1, conversation_id: 1})
       changeset = ConversationParts.create_changeset(%ConversationPart{}, attrs)
       assert changeset.valid?
+      assert changeset.changes.body == "Test body."
+      assert changeset.changes.part_type == "comment"
+    end
+
+    test "validates part_type inclusion: note" do
+      attrs = @valid_attrs |> Map.merge(%{author_id: 1, conversation_id: 1, part_type: "note"})
+      changeset = ConversationParts.create_changeset(%ConversationPart{}, attrs)
+      assert changeset.valid?
+    end
+
+    test "validates part_type inclusion: reopened" do
+      attrs = @valid_attrs |> Map.merge(%{author_id: 1, conversation_id: 1, part_type: "reopened"})
+      changeset = ConversationParts.create_changeset(%ConversationPart{}, attrs)
+      assert changeset.valid?
+    end
+
+    test "validates part_type inclusion: closed" do
+      attrs = @valid_attrs |> Map.merge(%{author_id: 1, conversation_id: 1, part_type: "closed"})
+      changeset = ConversationParts.create_changeset(%ConversationPart{}, attrs)
+      assert changeset.valid?
+    end
+
+    test "validates part_type inclusion: wat" do
+      attrs = @valid_attrs |> Map.merge(%{author_id: 1, conversation_id: 1, part_type: "wat"})
+      changeset = ConversationParts.create_changeset(%ConversationPart{}, attrs)
+      refute changeset.valid?
+      assert_error_message(changeset, :part_type, "is invalid")
     end
 
     test "requires author_id" do