diff --git a/core/lib/data_loader.js b/core/lib/data_loader.js
new file mode 100644
index 000000000..a91911f3e
--- /dev/null
+++ b/core/lib/data_loader.js
@@ -0,0 +1,63 @@
+"use strict";
+
+const glob = require('glob'),
+  _ = require('lodash'),
+  path = require('path'),
+  yaml = require('js-yaml');
+
+/**
+ * Loads a single config file, in yaml/json format.
+ *
+ * @param dataFilesPath - leave off the file extension.
+ * @param fsDep
+ * @returns {*}
+ */
+function loadFile(dataFilesPath, fsDep) {
+  const dataFilesFullPath = dataFilesPath + '*.{json,yml,yaml}';
+
+  if (dataFilesPath) {
+    const dataFiles = glob.sync(dataFilesFullPath),
+      dataFile = _.head(dataFiles);
+
+    if (dataFile && fsDep.existsSync(path.resolve(dataFile))) {
+      return yaml.safeLoad(fsDep.readFileSync(path.resolve(dataFile), 'utf8'));
+    }
+  }
+
+  return null;
+}
+
+/**
+ * Loads a set of config files from a folder, in yaml/json format.
+ *
+ * @param dataFilesPath - leave off the file extension
+ * @param excludeFileNames - leave off the file extension
+ * @param fsDep
+ * @returns Object, with merged data files, empty object if no files.
+ */
+function loadDataFromFolder(dataFilesPath, excludeFileNames, fsDep) {
+  const dataFilesFullPath = dataFilesPath + '*.{json,yml,yaml}',
+    excludeFullPath = dataFilesPath + excludeFileNames + '.{json,yml,yaml}';
+
+  let globOptions = {};
+  if (excludeFileNames) {
+    globOptions.ignore = [excludeFullPath];
+  }
+
+  const dataFiles = glob.sync(dataFilesFullPath, globOptions);
+  let mergeObject = {};
+
+  dataFiles.forEach(function (filePath) {
+    let jsonData = yaml.safeLoad(fsDep.readFileSync(path.resolve(filePath), 'utf8'));
+    mergeObject = _.merge(mergeObject, jsonData);
+  });
+
+  return mergeObject;
+}
+
+module.exports = function configFileLoader() {
+  return {
+    loadDataFromFile: loadFile,
+    loadDataFromFolder: loadDataFromFolder
+  };
+};
diff --git a/core/lib/pattern_assembler.js b/core/lib/pattern_assembler.js
index b85867d88..02f0dad13 100644
--- a/core/lib/pattern_assembler.js
+++ b/core/lib/pattern_assembler.js
@@ -8,6 +8,7 @@ var path = require('path'),
   pph = require('./pseudopattern_hunter'),
   mp = require('./markdown_parser'),
   plutils = require('./utilities'),
+  dataLoader = require('./data_loader')(),
   patternEngines = require('./pattern_engines'),
   lh = require('./lineage_hunter'),
   lih = require('./list_item_hunter'),
@@ -318,16 +319,13 @@ var pattern_assembler = function () {
 
     //look for a json file for this template
     try {
-      var jsonFilename = path.resolve(patternsPath, currentPattern.subdir, currentPattern.fileName + ".json");
-      try {
-        var jsonFilenameStats = fs.statSync(jsonFilename);
-      } catch (err) {
-        //not a file
-      }
-      if (jsonFilenameStats && jsonFilenameStats.isFile()) {
-        currentPattern.jsonFileData = fs.readJSONSync(jsonFilename);
+      var jsonFilename = path.resolve(patternsPath, currentPattern.subdir, currentPattern.fileName);
+      let configData = dataLoader.loadDataFromFile(jsonFilename, fs);
+
+      if (configData) {
+        currentPattern.jsonFileData = configData;
         if (patternlab.config.debug) {
-          console.log('processPatternIterative: found pattern-specific data.json for ' + currentPattern.patternPartial);
+          console.log('processPatternIterative: found pattern-specific config data for ' + currentPattern.patternPartial);
         }
       }
     }
@@ -338,17 +336,14 @@ var pattern_assembler = function () {
 
     //look for a listitems.json file for this template
     try {
-      var listJsonFileName = path.resolve(patternsPath, currentPattern.subdir, currentPattern.fileName + ".listitems.json");
-      try {
-        var listJsonFileStats = fs.statSync(listJsonFileName);
-      } catch (err) {
-        //not a file
-      }
-      if (listJsonFileStats && listJsonFileStats.isFile()) {
-        currentPattern.listitems = fs.readJSONSync(listJsonFileName);
+      var listJsonFileName = path.resolve(patternsPath, currentPattern.subdir, currentPattern.fileName + ".listitems");
+      let listItemsConfig = dataLoader.loadDataFromFile(listJsonFileName, fs);
+
+      if (listItemsConfig) {
+        currentPattern.listitems = listItemsConfig;
         buildListItems(currentPattern);
         if (patternlab.config.debug) {
-          console.log('found pattern-specific listitems.json for ' + currentPattern.patternPartial);
+          console.log('found pattern-specific listitems config for ' + currentPattern.patternPartial);
         }
       }
     }
diff --git a/core/lib/patternlab.js b/core/lib/patternlab.js
index f6d6bbffc..942880312 100644
--- a/core/lib/patternlab.js
+++ b/core/lib/patternlab.js
@@ -11,7 +11,6 @@
 "use strict";
 
 var diveSync = require('diveSync'),
-  glob = require('glob'),
   _ = require('lodash'),
   path = require('path'),
   chalk = require('chalk'),
@@ -20,6 +19,7 @@ var diveSync = require('diveSync'),
   pm = require('./plugin_manager'),
   fs = require('fs-extra'),
   packageInfo = require('../../package.json'),
+  dataLoader = require('./data_loader')(),
   plutils = require('./utilities'),
   PatternGraph = require('./pattern_graph').PatternGraph;
 
@@ -38,14 +38,14 @@ console.log(
 var patternEngines = require('./pattern_engines');
 var EventEmitter = require('events').EventEmitter;
 
+/**
+ * Given a path, load info from the folder to compile into a single config object.
+ * @param dataFilesPath
+ * @param fsDep
+ * @returns {{}}
+ */
 function buildPatternData(dataFilesPath, fsDep) {
-  var dataFiles = glob.sync(dataFilesPath + '*.json', {"ignore" : [dataFilesPath + 'listitems.json']});
-  var mergeObject = {};
-  dataFiles.forEach(function (filePath) {
-    var jsonData = fsDep.readJSONSync(path.resolve(filePath), 'utf8');
-    mergeObject = _.merge(mergeObject, jsonData);
-  });
-  return mergeObject;
+  return dataLoader.loadDataFromFolder(dataFilesPath, 'listitems', fsDep);
 }
 
 // GTP: these two diveSync pattern processors factored out so they can be reused
@@ -492,9 +492,9 @@ var patternlab_engine = function (config) {
       patternlab.data = {};
     }
     try {
-      patternlab.listitems = fs.readJSONSync(path.resolve(paths.source.data, 'listitems.json'));
+      patternlab.listitems = dataLoader.loadDataFromFile(path.resolve(paths.source.data, 'listitems.{json,yml,yaml}'));
     } catch (ex) {
-      plutils.warning('WARNING: missing or malformed ' + paths.source.data + 'listitems.json file.  Pattern Lab may not work without this file.');
+      plutils.warning('WARNING: missing or malformed ' + paths.source.data + 'listitems file.  Pattern Lab may not work without this file.');
       patternlab.listitems = {};
     }
     try {
diff --git a/test/data_loader_tests.js b/test/data_loader_tests.js
new file mode 100644
index 000000000..3be872e76
--- /dev/null
+++ b/test/data_loader_tests.js
@@ -0,0 +1,13 @@
+'use strict';
+
+const tap = require('tap');
+
+tap.test('loadDataFromFile - Load ', function(test){
+  const fs = require('fs-extra'),
+    dataLoader = require('../core/lib/data_loader')(),
+    data_dir = './test/files/_data/';
+
+  let data = dataLoader.loadDataFromFile(data_dir + 'foo', fs);
+  test.equals(data.foo, 'bar');
+  test.end();
+});
diff --git a/test/files/_data/data.json b/test/files/_data/data.json
index d6d8ef572..1e3cc53b3 100644
--- a/test/files/_data/data.json
+++ b/test/files/_data/data.json
@@ -1,2 +1,2 @@
-{ "data" : "test" }
+{ "data" : "test", "from_json" : "from_json" }
 
diff --git a/test/files/_data/data.yaml b/test/files/_data/data.yaml
new file mode 100644
index 000000000..50c5fd0cd
--- /dev/null
+++ b/test/files/_data/data.yaml
@@ -0,0 +1 @@
+from_yaml: "from_yaml"
diff --git a/test/files/_data/data.yml b/test/files/_data/data.yml
new file mode 100644
index 000000000..e64d69624
--- /dev/null
+++ b/test/files/_data/data.yml
@@ -0,0 +1 @@
+from_yml: "from_yml"
diff --git a/test/patternlab_tests.js b/test/patternlab_tests.js
index 84eb81d2f..463d342ad 100644
--- a/test/patternlab_tests.js
+++ b/test/patternlab_tests.js
@@ -1,15 +1,27 @@
 'use strict';
 
-var tap = require('tap');
+const tap = require('tap');
 
 tap.test('buildPatternData - should merge all JSON files in the data folder except listitems', function(test){
-  var fs = require('fs-extra');
-        var plMain = require('../core/lib/patternlab');
-  var data_dir = './test/files/_data/';
+  const fs = require('fs-extra'),
+    plMain = require('../core/lib/patternlab'),
+    data_dir = './test/files/_data/';
 
-  var dataResult = plMain.build_pattern_data(data_dir, fs);
+  let dataResult = plMain.build_pattern_data(data_dir, fs);
   test.equals(dataResult.data, "test");
   test.equals(dataResult.foo, "bar");
   test.equals(dataResult.test_list_item, undefined);
   test.end();
 });
+
+tap.test('buildPatternData - can load json, yaml, and yml files', function(test) {
+  const fs = require('fs-extra'),
+    plMain = require('../core/lib/patternlab'),
+    data_dir = './test/files/_data/';
+
+  let dataResult = plMain.build_pattern_data(data_dir, fs);
+  test.equals(dataResult.from_yml, "from_yml");
+  test.equals(dataResult.from_yaml, "from_yaml");
+  test.equals(dataResult.from_json, "from_json");
+  test.end();
+});