diff --git a/conservancy_beancount/reconcile/helper.py b/conservancy_beancount/reconcile/helper.py
index 54733104253990139232e1bbbb45af47db4786ce..708008e698ce4c6a94649a425e9ba79e4c372114 100644
--- a/conservancy_beancount/reconcile/helper.py
+++ b/conservancy_beancount/reconcile/helper.py
@@ -20,19 +20,21 @@ import datetime
 import io
 import tempfile
 import textwrap
+import typing
+from typing import List
 import os
 
 from beancount import loader
 from beancount.query.query import run_query
 
 
-def end_of_month(date):
+def end_of_month(date: datetime.date) -> datetime.date:
     """Given a date, return the last day of the month."""
     # Using 'day' replaces, rather than adds.
     return date + relativedelta(day=31)
 
 
-def format_record_for_grep(row, homedir):
+def format_record_for_grep(row: typing.List, homedir: str) -> typing.List:
     """Return a line in a grep-style.
 
     This is so the line can be fed into Emacs grep-mode for quickly jumping to
@@ -42,7 +44,7 @@ def format_record_for_grep(row, homedir):
     return [f'{file}:{row[1]}:'] + row[2:]
 
 
-def max_column_widths(rows):
+def max_column_widths(rows: List) -> List[int]:
     """Return the max width for each column in a table of data."""
     if not rows:
         return []
@@ -55,7 +57,7 @@ def max_column_widths(rows):
         return maxes
 
 
-def tabulate(rows, headers=None):
+def tabulate(rows: List, headers: List=None) -> str:
     """Format a table of data as a string.
 
     Implemented here to avoid adding dependency on "tabulate" package.
@@ -101,8 +103,9 @@ else:
     if not (args.cur_end_date and args.prev_end_date):
         parser.error(' --prev-end-date and --cur-end-date must be used together')
     preDate = args.prev_end_date
-    lastDateInPeriod = args.cur_end_date
-    month = lastDateInPeriod.strftime('%Y-%m')
+    lastDateInPeriod = args.cur_end_date.isoformat()
+    month = args.cur_end_date.strftime('%Y-%m')
+grep_output_file: typing.IO
 if args.grep_output_filename:
     grep_output_file = open(args.grep_output_filename, 'w')
 else:
@@ -168,7 +171,7 @@ for desc, query in QUERIES.items():
     if not rrows:
         print(f'{desc:<55} {"N/A":>11}')
     elif desc.startswith('04'):
-        homedir = os.getenv('HOME')
+        homedir = os.getenv('HOME', '')
         print(f'{desc}\n   See {grep_output_file.name}')
         grep_rows = [format_record_for_grep(row, homedir) for row in rrows]
         print(tabulate(grep_rows), file=grep_output_file)
diff --git a/conservancy_beancount/reconcile/prototype_amex_reconciler.py b/conservancy_beancount/reconcile/prototype_amex_reconciler.py
index 1f680b1ba2b585851af6a9ceb921e07697fc88c1..982874de9476836add6a726565c4708131dec186 100644
--- a/conservancy_beancount/reconcile/prototype_amex_reconciler.py
+++ b/conservancy_beancount/reconcile/prototype_amex_reconciler.py
@@ -10,14 +10,15 @@ import argparse
 import csv
 import datetime
 import decimal
+from typing import Dict, List, Tuple
 
 from beancount import loader
 from beancount.query.query import run_query
-from thefuzz import fuzz
+from thefuzz import fuzz  # type: ignore
 
 # NOTE: Statement doesn't seem to give us a running balance or a final total.
 
-def standardize_amex_record(row):
+def standardize_amex_record(row: Dict) -> Dict:
     return {
         'date': datetime.datetime.strptime(row['Date'], '%m/%d/%Y').date(),
         'amount': -1 * decimal.Decimal(row['Amount']),
@@ -25,7 +26,7 @@ def standardize_amex_record(row):
     }
 
 
-def standardize_beancount_record(row):
+def standardize_beancount_record(row) -> Dict:  # type: ignore[no-untyped-def]
     return {
         'date': row.date,
         'amount': row.number_cost_position,
@@ -33,15 +34,15 @@ def standardize_beancount_record(row):
     }
 
 
-def format_record(record):
+def format_record(record: Dict) -> str:
     return f"{record['date'].isoformat()}: {record['amount']:>8} {record['payee'][:20]:<20}"
 
 
-def sort_records(records):
+def sort_records(records: List) -> List:
     return sorted(records, key=lambda x: (x['date'], x['amount']))
 
 
-def records_match(r1, r2):
+def records_match(r1: Dict, r2: Dict) -> Tuple[bool, str]:
     """Do these records represent the same transaction?"""
     date_matches = r1['date'] >= r2['date'] - datetime.timedelta(days=1) and r1['date'] <= r2['date'] + datetime.timedelta(days=1)
     amount_matches = r1['amount'] == r2['amount']