diff --git a/pandas/core/panel.py b/pandas/core/panel.py
index e4515efe109c58..906866a3580298 100644
--- a/pandas/core/panel.py
+++ b/pandas/core/panel.py
@@ -26,7 +26,7 @@
 from pandas.core.frame import DataFrame
 from pandas.core.generic import NDFrame, _shared_docs
 from pandas.core.index import (Index, MultiIndex, _ensure_index,
-                               _get_combined_index)
+                               _get_objs_combined_axis)
 from pandas.io.formats.printing import pprint_thing
 from pandas.core.indexing import maybe_droplevels
 from pandas.core.internals import (BlockManager,
@@ -1448,7 +1448,6 @@ def _extract_axis(self, data, axis=0, intersect=False):
             index = Index([])
         elif len(data) > 0:
             raw_lengths = []
-            indexes = []
 
         have_raw_arrays = False
         have_frames = False
@@ -1456,13 +1455,14 @@ def _extract_axis(self, data, axis=0, intersect=False):
         for v in data.values():
             if isinstance(v, self._constructor_sliced):
                 have_frames = True
-                indexes.append(v._get_axis(axis))
             elif v is not None:
                 have_raw_arrays = True
                 raw_lengths.append(v.shape[axis])
 
         if have_frames:
-            index = _get_combined_index(indexes, intersect=intersect)
+            index = _get_objs_combined_axis(data.values(), axis=axis,
+                                            intersect=intersect)
+
 
         if have_raw_arrays:
             lengths = list(set(raw_lengths))
diff --git a/pandas/core/reshape/concat.py b/pandas/core/reshape/concat.py
index e199ec27103674..5f79fc5f6991d9 100644
--- a/pandas/core/reshape/concat.py
+++ b/pandas/core/reshape/concat.py
@@ -4,7 +4,7 @@
 
 import numpy as np
 from pandas import compat, DataFrame, Series, Index, MultiIndex
-from pandas.core.index import (_get_combined_index,
+from pandas.core.index import (_get_objs_combined_axis,
                                _ensure_index, _get_consensus_names,
                                _all_indexes_same)
 from pandas.core.categorical import (_factorize_from_iterable,
@@ -445,16 +445,13 @@ def _get_new_axes(self):
         return new_axes
 
     def _get_comb_axis(self, i):
-        if self._is_series:
-            all_indexes = [x.index for x in self.objs]
-        else:
-            try:
-                all_indexes = [x._data.axes[i] for x in self.objs]
-            except IndexError:
-                types = [type(x).__name__ for x in self.objs]
-                raise TypeError("Cannot concatenate list of %s" % types)
-
-        return _get_combined_index(all_indexes, intersect=self.intersect)
+        data_axis = 1 - i if self.objs[0].ndim == 2 else i
+        try:
+            return _get_objs_combined_axis(self.objs, axis=data_axis,
+                                           intersect=self.intersect)
+        except IndexError:
+            types = [type(x).__name__ for x in self.objs]
+            raise TypeError("Cannot concatenate list of %s" % types)
 
     def _get_concat_axis(self):
         """