diff --git a/pandas/core/internals/managers.py b/pandas/core/internals/managers.py
index a7a9a77bab3bc..0ec281bb0fdce 100644
--- a/pandas/core/internals/managers.py
+++ b/pandas/core/internals/managers.py
@@ -1845,7 +1845,7 @@ def _consolidate(blocks):
     gkey = lambda x: x._consolidate_key
     grouper = itertools.groupby(sorted(blocks, key=gkey), gkey)
 
-    new_blocks = []
+    new_blocks: List[Block] = []
     for (_can_consolidate, dtype), group_blocks in grouper:
         merged_blocks = _merge_blocks(
             list(group_blocks), dtype=dtype, can_consolidate=_can_consolidate
diff --git a/pandas/core/missing.py b/pandas/core/missing.py
index f3229b2876e5d..f2ec04c1fc05d 100644
--- a/pandas/core/missing.py
+++ b/pandas/core/missing.py
@@ -717,8 +717,8 @@ def inner(invalid, limit):
             # just use forwards
             return f_idx
         else:
-            b_idx = list(inner(invalid[::-1], bw_limit))
-            b_idx = set(N - 1 - np.asarray(b_idx))
+            b_idx_inv = list(inner(invalid[::-1], bw_limit))
+            b_idx = set(N - 1 - np.asarray(b_idx_inv))
             if fw_limit == 0:
                 return b_idx
 
diff --git a/pandas/core/ops/docstrings.py b/pandas/core/ops/docstrings.py
index e3a68ad328d55..839bdbfb2444a 100644
--- a/pandas/core/ops/docstrings.py
+++ b/pandas/core/ops/docstrings.py
@@ -4,7 +4,7 @@
 from typing import Dict, Optional
 
 
-def _make_flex_doc(op_name, typ):
+def _make_flex_doc(op_name, typ: str):
     """
     Make the appropriate substitutions for the given operation and class-typ
     into either _flex_doc_SERIES or _flex_doc_FRAME to return the docstring
@@ -22,10 +22,12 @@ def _make_flex_doc(op_name, typ):
     op_name = op_name.replace("__", "")
     op_desc = _op_descriptions[op_name]
 
+    op_desc_op = op_desc["op"]
+    assert op_desc_op is not None  # for mypy
     if op_name.startswith("r"):
-        equiv = "other " + op_desc["op"] + " " + typ
+        equiv = "other " + op_desc_op + " " + typ
     else:
-        equiv = typ + " " + op_desc["op"] + " other"
+        equiv = typ + " " + op_desc_op + " other"
 
     if typ == "series":
         base_doc = _flex_doc_SERIES
@@ -39,8 +41,9 @@ def _make_flex_doc(op_name, typ):
             equiv=equiv,
             series_returns=op_desc["series_returns"],
         )
-        if op_desc["series_examples"]:
-            doc = doc_no_examples + op_desc["series_examples"]
+        ser_example = op_desc["series_examples"]
+        if ser_example:
+            doc = doc_no_examples + ser_example
         else:
             doc = doc_no_examples
     elif typ == "dataframe":
diff --git a/pandas/io/html.py b/pandas/io/html.py
index 9a91b16e52723..1534e42d8fb5a 100644
--- a/pandas/io/html.py
+++ b/pandas/io/html.py
@@ -8,7 +8,7 @@
 import numbers
 import os
 import re
-from typing import Dict, List, Optional, Pattern, Sequence, Union
+from typing import Dict, List, Optional, Pattern, Sequence, Tuple, Union
 
 from pandas._typing import FilePathOrBuffer
 from pandas.compat._optional import import_optional_dependency
@@ -435,7 +435,7 @@ def _expand_colspan_rowspan(self, rows):
         to subsequent cells.
         """
         all_texts = []  # list of rows, each a list of str
-        remainder = []  # list of (index, text, nrows)
+        remainder: List[Tuple[int, str, int]] = []  # list of (index, text, nrows)
 
         for tr in rows:
             texts = []  # the output for this row
@@ -910,6 +910,7 @@ def _parse(flavor, io, match, attrs, encoding, displayed_only, **kwargs):
         else:
             break
     else:
+        assert retained is not None  # for mypy
         raise retained
 
     ret = []
diff --git a/setup.cfg b/setup.cfg
index ee28646d722f2..6c65695f6bc4a 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -202,18 +202,6 @@ check_untyped_defs=False
 [mypy-pandas.core.internals.construction]
 check_untyped_defs=False
 
-[mypy-pandas.core.internals.managers]
-check_untyped_defs=False
-
-[mypy-pandas.core.internals.ops]
-check_untyped_defs=False
-
-[mypy-pandas.core.missing]
-check_untyped_defs=False
-
-[mypy-pandas.core.ops.docstrings]
-check_untyped_defs=False
-
 [mypy-pandas.core.resample]
 check_untyped_defs=False
 
@@ -253,9 +241,6 @@ check_untyped_defs=False
 [mypy-pandas.io.formats.style]
 check_untyped_defs=False
 
-[mypy-pandas.io.html]
-check_untyped_defs=False
-
 [mypy-pandas.io.json._json]
 check_untyped_defs=False