diff -r dd8f48ff9480 Lib/collections/__init__.py
--- a/Lib/collections/__init__.py	Tue Apr 14 00:15:42 2015 -0700
+++ b/Lib/collections/__init__.py	Wed Apr 15 17:26:43 2015 -0400
@@ -1060,6 +1060,8 @@
     def __float__(self): return float(self.data)
     def __complex__(self): return complex(self.data)
     def __hash__(self): return hash(self.data)
+    def __getnewargs__(self):
+        return (self.data[:],)
 
     def __eq__(self, string):
         if isinstance(string, UserString):
@@ -1104,9 +1106,13 @@
     __rmul__ = __mul__
     def __mod__(self, args):
         return self.__class__(self.data % args)
+    def __rmod__(self, format):
+        return self.__class__(format % args)
 
     # the following methods are defined in alphabetical order:
     def capitalize(self): return self.__class__(self.data.capitalize())
+    def casefold(self):
+        return self.__class__(self.data.casefold())
     def center(self, width, *args):
         return self.__class__(self.data.center(width, *args))
     def count(self, sub, start=0, end=_sys.maxsize):
@@ -1129,6 +1135,8 @@
         return self.data.find(sub, start, end)
     def format(self, *args, **kwds):
         return self.data.format(*args, **kwds)
+    def format_map(self, mapping):
+        return self.data.format_map(mapping)
     def index(self, sub, start=0, end=_sys.maxsize):
         return self.data.index(sub, start, end)
     def isalpha(self): return self.data.isalpha()
@@ -1138,6 +1146,7 @@
     def isidentifier(self): return self.data.isidentifier()
     def islower(self): return self.data.islower()
     def isnumeric(self): return self.data.isnumeric()
+    def isprintable(self): return self.data.isprintable()
     def isspace(self): return self.data.isspace()
     def istitle(self): return self.data.istitle()
     def isupper(self): return self.data.isupper()
@@ -1146,6 +1155,7 @@
         return self.__class__(self.data.ljust(width, *args))
     def lower(self): return self.__class__(self.data.lower())
     def lstrip(self, chars=None): return self.__class__(self.data.lstrip(chars))
+    maketrans = str.maketrans
     def partition(self, sep):
         return self.data.partition(sep)
     def replace(self, old, new, maxsplit=-1):
diff -r dd8f48ff9480 Lib/test/test_collections.py
--- a/Lib/test/test_collections.py	Tue Apr 14 00:15:42 2015 -0700
+++ b/Lib/test/test_collections.py	Wed Apr 15 17:26:43 2015 -0400
@@ -11,9 +11,9 @@
 import keyword
 import re
 import sys
-from collections import UserDict
 from collections import ChainMap
 from collections import deque
+from collections import UserString, UserList, UserDict
 from collections.abc import Hashable, Iterable, Iterator
 from collections.abc import Sized, Container, Callable
 from collections.abc import Set, MutableSet
@@ -22,6 +22,26 @@
 from collections.abc import ByteString
 
 
+class TestUserObjects(unittest.TestCase):
+    def _superset_test(self, a, b):
+        self.assertGreaterEqual(
+            set(dir(a)),
+            set(dir(b)),
+            '{a} should have all the methods of {b}'.format(
+                a=a.__name__,
+                b=b.__name__,
+            ),
+        )
+    def test_str_protocol(self):
+        self._superset_test(UserString, str)
+
+    def test_list_protocol(self):
+        self._superset_test(UserList, list)
+
+    def test_dict_protocol(self):
+        self._superset_test(UserDict, dict)
+
+
 ################################################################################
 ### ChainMap (helper class for configparser and the string module)
 ################################################################################
@@ -1642,7 +1662,8 @@
     NamedTupleDocs = doctest.DocTestSuite(module=collections)
     test_classes = [TestNamedTuple, NamedTupleDocs, TestOneTrickPonyABCs,
                     TestCollectionABCs, TestCounter, TestChainMap,
-                    TestOrderedDict, GeneralMappingTests, SubclassMappingTests]
+                    TestOrderedDict, GeneralMappingTests, SubclassMappingTests,
+                    TestUserObjects]
     support.run_unittest(*test_classes)
     support.run_doctest(collections, verbose)
 
diff -r dd8f48ff9480 Misc/NEWS
--- a/Misc/NEWS	Tue Apr 14 00:15:42 2015 -0700
+++ b/Misc/NEWS	Wed Apr 15 17:26:43 2015 -0400
@@ -31,6 +31,8 @@
 Library
 -------
 
+- Issue #22189: Adds missing methods to collections.UserString.
+
 - Issue #21116: Avoid blowing memory when allocating a multiprocessing shared
   array that's larger than 50% of the available RAM.  Patch by Médéric Boquien.