diff --git a/index.html b/index.html
index 16dce5779..5853a8a50 100644
--- a/index.html
+++ b/index.html
@@ -71,6 +71,7 @@
 
         <script src='js/id/actions.js'></script>
         <script src='js/id/actions/add_node.js'></script>
+        <script src='js/id/actions/add_relation_member.js'></script>
         <script src='js/id/actions/add_way.js'></script>
         <script src='js/id/actions/add_way_node.js'></script>
         <script src='js/id/actions/change_entity_tags.js'></script>
diff --git a/js/id/actions/add_relation_member.js b/js/id/actions/add_relation_member.js
new file mode 100644
index 000000000..45e24a0b0
--- /dev/null
+++ b/js/id/actions/add_relation_member.js
@@ -0,0 +1,9 @@
+iD.actions.AddRelationMember = function(relationId, member, index) {
+    return function(graph) {
+        var relation = graph.entity(relationId),
+            members = relation.members.slice();
+
+        members.splice((index === undefined) ? members.length : index, 0, member);
+        return graph.replace(relation.update({members: members}));
+    };
+};
diff --git a/test/index.html b/test/index.html
index 0777751d5..425258d20 100644
--- a/test/index.html
+++ b/test/index.html
@@ -66,6 +66,7 @@
 
     <script src='../js/id/actions.js'></script>
     <script src='../js/id/actions/add_node.js'></script>
+    <script src="../js/id/actions/add_relation_member.js"></script>
     <script src='../js/id/actions/add_way.js'></script>
     <script src='../js/id/actions/add_way_node.js'></script>
     <script src='../js/id/actions/change_entity_tags.js'></script>
@@ -124,6 +125,7 @@
 
     <!-- include spec files here... -->
     <script src="spec/actions/add_node.js"></script>
+    <script src="spec/actions/add_relation_member.js"></script>
     <script src="spec/actions/add_way.js"></script>
     <script src="spec/actions/add_way_node.js"></script>
     <script src="spec/actions/change_entity_tags.js"></script>
diff --git a/test/index_packaged.html b/test/index_packaged.html
index 630ed1088..8def4c0da 100644
--- a/test/index_packaged.html
+++ b/test/index_packaged.html
@@ -31,6 +31,7 @@
 
     <!-- include spec files here... -->
     <script src="spec/actions/add_node.js"></script>
+    <script src="spec/actions/add_relation_member.js"></script>
     <script src="spec/actions/add_way.js"></script>
     <script src="spec/actions/add_way_node.js"></script>
     <script src="spec/actions/change_entity_tags.js"></script>
diff --git a/test/spec/actions/add_relation_member.js b/test/spec/actions/add_relation_member.js
new file mode 100644
index 000000000..aeae8e353
--- /dev/null
+++ b/test/spec/actions/add_relation_member.js
@@ -0,0 +1,37 @@
+describe("iD.actions.AddRelationMember", function () {
+    it("adds a member at the end of the relation", function () {
+        var relation = iD.Relation(),
+            graph    = iD.Graph([relation]);
+
+        graph = iD.actions.AddRelationMember(relation.id, {id: '1'})(graph);
+
+        expect(graph.entity(relation.id).members).to.eql([{id: '1'}]);
+    });
+
+    it("adds a member at index 0", function () {
+        var relation = iD.Relation({members: [{id: '1'}]}),
+            graph    = iD.Graph([relation]);
+
+        graph = iD.actions.AddRelationMember(relation.id, {id: '2'}, 0)(graph);
+
+        expect(graph.entity(relation.id).members).to.eql([{id: '2'}, {id: '1'}]);
+    });
+
+    it("adds a member at a positive index", function () {
+        var relation = iD.Relation({members: [{id: '1'}, {id: '3'}]}),
+            graph    = iD.Graph([relation]);
+
+        graph = iD.actions.AddRelationMember(relation.id, {id: '2'}, 1)(graph);
+
+        expect(graph.entity(relation.id).members).to.eql([{id: '1'}, {id: '2'}, {id: '3'}]);
+    });
+
+    it("adds a member at a negative index", function () {
+        var relation = iD.Relation({members: [{id: '1'}, {id: '3'}]}),
+            graph    = iD.Graph([relation]);
+
+        graph = iD.actions.AddRelationMember(relation.id, {id: '2'}, -1)(graph);
+
+        expect(graph.entity(relation.id).members).to.eql([{id: '1'}, {id: '2'}, {id: '3'}]);
+    });
+});