--- /dev/null
+var baseSortedIndex = require('./internal/baseSortedIndex');
+
+/**
+ * Uses a binary search to determine the lowest index at which `value` should
+ * be inserted into `array` in order to maintain its sort order.
+ *
+ * @static
+ * @memberOf _
+ * @category Array
+ * @param {Array} array The sorted array to inspect.
+ * @param {*} value The value to evaluate.
+ * @returns {number} Returns the index at which `value` should be inserted into `array`.
+ * @example
+ *
+ * _.sortedIndex([30, 50], 40);
+ * // => 1
+ *
+ * _.sortedIndex([4, 5], 4);
+ * // => 0
+ */
+function sortedIndex(array, value) {
+ return baseSortedIndex(array, value);
+}
+
+module.exports = sortedIndex;