diff --git a/conservancy_beancount/reports/balance_sheet.py b/conservancy_beancount/reports/balance_sheet.py
index 14a5caf..f937b72 100644
--- a/conservancy_beancount/reports/balance_sheet.py
+++ b/conservancy_beancount/reports/balance_sheet.py
@@ -148,12 +148,25 @@ class Balances:
               period: int=Period.ANY,
               fund: int=Fund.ANY,
               post_type: Optional[str]=None,
+              *,
+              account_exact: bool=False,
     ) -> core.Balance:
         if isinstance(account, str):
             account = (account,)
+        acct_pred: Callable[[data.Account], bool]
+        if account is None:
+            acct_pred = lambda acct: True
+        elif account_exact:
+            # At this point, between this isinstance() above and the earlier
+            # `account is None` check, we've collapsed the type of `account` to
+            # `Collection[str]`. Unfortunately the logic is too involved for
+            # mypy to follow, so ignore the type problem.
+            acct_pred = lambda acct: acct in account  # type:ignore[operator]
+        else:
+            acct_pred = lambda acct: acct.is_under(*account) is not None  # type:ignore[misc]
         retval = core.MutableBalance()
         for key, balance in self.balances.items():
-            if not (account is None or key.account.is_under(*account)):
+            if not acct_pred(key.account):
                 pass
             elif not (classification is None
                       or key.classification.is_under(classification)):
@@ -599,10 +612,14 @@ class Report(core.BaseODS[Sequence[None], None]):
             want_balance = acct_root not in EQUITY_ACCOUNTS
             self.add_row()
             for account in self.balances.iter_accounts(acct_root):
-                period_bal = self.balances.total(account=account, period=Period.PERIOD)
-                prior_bal = self.balances.total(account=account, period=Period.PRIOR)
+                period_bal = self.balances.total(
+                    account=account, period=Period.PERIOD, account_exact=True,
+                )
+                prior_bal = self.balances.total(
+                    account=account, period=Period.PRIOR, account_exact=True,
+                )
                 if want_balance:
-                    close_bal = self.balances.total(account=account)
+                    close_bal = self.balances.total(account=account, account_exact=True)
                     close_cell = self.balance_cell(norm_func(close_bal))
                     open_cell = self.balance_cell(norm_func(close_bal - period_bal))
                 else: