diff --git a/core/generator.js b/core/generator.js
index 6937042d5..f556f6894 100644
--- a/core/generator.js
+++ b/core/generator.js
@@ -172,6 +172,10 @@ Blockly.Generator.prototype.blockToCode = function(block, opt_thisOnly) {
     // Skip past this block if it is disabled.
     return opt_thisOnly ? '' : this.blockToCode(block.getNextBlock());
   }
+  if (block.isInsertionMarker()) {
+    // Skip past insertion markers.
+    return opt_thisOnly ? '' : this.blockToCode(block.getChildren(false)[0]);
+  }
 
   var func = this[block.type];
   if (typeof func != 'function') {
diff --git a/tests/mocha/index.html b/tests/mocha/index.html
index 75869ca30..7e835769a 100644
--- a/tests/mocha/index.html
+++ b/tests/mocha/index.html
@@ -59,6 +59,7 @@
     <script src="generator_test.js"></script>
     <script src="gesture_test.js"></script>
     <script src="input_test.js"></script>
+    <script src="insertion_marker_test.js"></script>
     <script src="json_test.js"></script>
     <script src="key_map_test.js"></script>
     <script src="logic_ternary_test.js"></script>
diff --git a/tests/mocha/insertion_marker_test.js b/tests/mocha/insertion_marker_test.js
new file mode 100644
index 000000000..3a43c8561
--- /dev/null
+++ b/tests/mocha/insertion_marker_test.js
@@ -0,0 +1,203 @@
+/**
+ * @license
+ * Copyright 2019 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+suite('InsertionMarkers', function() {
+  setup(function() {
+    this.workspace = new Blockly.Workspace();
+    Blockly.defineBlocksWithJsonArray([
+      {
+        "type": "stack_block",
+        "message0": "",
+        "previousStatement": null,
+        "nextStatement": null
+      },
+      {
+        "type": "row_block",
+        "message0": "%1",
+        "args0": [
+          {
+            "type": "input_value",
+            "name": "INPUT"
+          }
+        ],
+        "output": null
+      },
+      {
+        "type": "statement_block",
+        "message0": "%1",
+        "args0": [
+          {
+            "type": "input_statement",
+            "name": "STATEMENT"
+          }
+        ],
+        "previousStatement": null,
+        "nextStatement": null
+      }]);
+  });
+  teardown(function() {
+    this.workspace.dispose();
+    delete Blockly.Blocks['stack_block'];
+    delete Blockly.Blocks['row_block'];
+    delete Blockly.Blocks['statement_block'];
+  });
+  suite('Code Generation', function() {
+    setup(function() {
+      Blockly.JavaScript['stack_block'] = function(_) {
+        return 'stack;\n';
+      };
+      Blockly.JavaScript['row_block'] = function(block) {
+        var value = Blockly.JavaScript
+            .valueToCode(block, 'INPUT', Blockly.JavaScript.ORDER_NONE);
+        var code = 'row(' + value + ')';
+        return [code, Blockly.JavaScript.ORDER_NONE];
+      };
+      Blockly.JavaScript['statement_block'] = function(block) {
+        return 'statement{\n' + Blockly.JavaScript
+            .statementToCode(block, 'STATEMENT') + '};\n';
+      };
+
+      this.assertGen = function(xml, expectedCode) {
+        Blockly.Xml.domToWorkspace(xml, this.workspace);
+        var block = this.workspace.getBlockById('insertion');
+        block.isInsertionMarker_ = true;
+        var code = Blockly.JavaScript.workspaceToCode(this.workspace);
+        chai.assert.equal(code, expectedCode);
+      };
+    });
+    teardown(function() {
+      delete Blockly.JavaScript['stack_block'];
+      delete Blockly.JavaScript['row_block'];
+      delete Blockly.JavaScript['statement_block'];
+      delete this.assertGen;
+    });
+    test('Marker Surrounds', function() {
+      var xml = Blockly.Xml.textToDom(
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '  <block type="statement_block" id="insertion">' +
+          '    <statement name="STATEMENT">' +
+          '      <block type="statement_block"/>' +
+          '    </statement>' +
+          '  </block>' +
+          '</xml>');
+      this.assertGen(xml, 'statement{\n};\n');
+    });
+    test('Marker Enclosed', function() {
+      var xml = Blockly.Xml.textToDom(
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '  <block type="statement_block">' +
+          '    <statement name="STATEMENT">' +
+          '      <block type="statement_block" id="insertion"/>' +
+          '    </statement>' +
+          '  </block>' +
+          '</xml>');
+      this.assertGen(xml, 'statement{\n};\n');
+    });
+    test('Marker Enclosed and Surrounds', function() {
+      var xml = Blockly.Xml.textToDom(
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '  <block type="statement_block">' +
+          '    <statement name="STATEMENT">' +
+          '      <block type="statement_block" id="insertion">' +
+          '        <statement name="STATEMENT">' +
+          '          <block type="statement_block"/>' +
+          '        </statement>' +
+          '      </block>' +
+          '    </statement>' +
+          '  </block>' +
+          '</xml>');
+      this.assertGen(xml,
+          'statement{\n' +
+          '  statement{\n' +
+          '  };\n' +
+          '};\n');
+    });
+    test('Marker Prev', function() {
+      var xml = Blockly.Xml.textToDom(
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '  <block type="stack_block" id="insertion">' +
+          '    <next>' +
+          '      <block type="stack_block"/>' +
+          '    </next>' +
+          '  </block>' +
+          '</xml>');
+      this.assertGen(xml, 'stack;\n');
+    });
+    test('Marker Next', function() {
+      var xml = Blockly.Xml.textToDom(
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '  <block type="stack_block">' +
+          '    <next>' +
+          '      <block type="stack_block" id="insertion"/>' +
+          '    </next>' +
+          '  </block>' +
+          '</xml>');
+      this.assertGen(xml, 'stack;\n');
+    });
+    test('Marker Middle of Stack', function() {
+      var xml = Blockly.Xml.textToDom(
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '  <block type="stack_block">' +
+          '    <next>' +
+          '      <block type="stack_block" id="insertion">' +
+          '        <next>' +
+          '          <block type="stack_block"/>' +
+          '        </next>' +
+          '      </block>' +
+          '    </next>' +
+          '  </block>' +
+          '</xml>');
+      this.assertGen(xml,
+          'stack;\n' +
+          'stack;\n');
+    });
+    test('Marker On Output', function() {
+      var xml = Blockly.Xml.textToDom(
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '  <block type="row_block" id="insertion">' +
+          '    <value name="INPUT">' +
+          '      <block type="row_block"/>' +
+          '    </value>' +
+          '  </block>' +
+          '</xml>');
+      this.assertGen(xml, 'row();\n');
+    });
+    test('Marker On Input', function() {
+      var xml = Blockly.Xml.textToDom(
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '  <block type="row_block">' +
+          '    <value name="INPUT">' +
+          '      <block type="row_block" id="insertion"/>' +
+          '    </value>' +
+          '  </block>' +
+          '</xml>');
+      this.assertGen(xml, 'row();\n');
+    });
+    test('Marker Middle of Row', function() {
+      var xml = Blockly.Xml.textToDom(
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '  <block type="row_block">' +
+          '    <value name="INPUT">' +
+          '      <block type="row_block" id="insertion">' +
+          '        <value name="INPUT">' +
+          '          <block type="row_block"/>' +
+          '        </value>' +
+          '      </block>' +
+          '    </value>' +
+          '  </block>' +
+          '</xml>');
+      this.assertGen(xml, 'row(row());\n');
+    });
+    test('Marker Detatched', function() {
+      var xml = Blockly.Xml.textToDom(
+          '<xml xmlns="https://developers.google.com/blockly/xml">' +
+          '  <block type="stack_block" id="insertion"/>' +
+          '  <block type="stack_block"/>' +
+          '</xml>');
+      this.assertGen(xml, 'stack;\n');
+    });
+  });
+});