diff --git a/biweeklybudget/alembic/versions/9dc8545963be_account_interest_and_payoff_attributes.py b/biweeklybudget/alembic/versions/9dc8545963be_account_interest_and_payoff_attributes.py
index 2285bb5f..4a9d891e 100644
--- a/biweeklybudget/alembic/versions/9dc8545963be_account_interest_and_payoff_attributes.py
+++ b/biweeklybudget/alembic/versions/9dc8545963be_account_interest_and_payoff_attributes.py
@@ -26,6 +26,14 @@ def upgrade():
             nullable=True
         )
     )
+    op.add_column(
+        'accounts',
+        sa.Column(
+            'prime_rate_margin',
+            sa.Numeric(precision=5, scale=4),
+            nullable=True
+        )
+    )
     op.add_column(
         'accounts',
         sa.Column(
@@ -47,4 +55,5 @@ def upgrade():
 def downgrade():
     op.drop_column('accounts', 'min_payment_class_name')
     op.drop_column('accounts', 'interest_class_name')
+    op.drop_column('accounts', 'prime_rate_margin')
     op.drop_column('accounts', 'apr')
diff --git a/biweeklybudget/flaskapp/templates/account.html b/biweeklybudget/flaskapp/templates/account.html
index 86ef86f5..b9a4d368 100644
--- a/biweeklybudget/flaskapp/templates/account.html
+++ b/biweeklybudget/flaskapp/templates/account.html
@@ -40,6 +40,14 @@
                                             <th>APR</th>
                                             <td>{{ acct.apr|decimal_to_percent }}%</td>
                                         </tr>
+                                        <tr>
+                                            <th>Prime Rate Margin</th>
+                                            <td>{{ acct.prime_rate_margin|decimal_to_percent }}</td>
+                                        </tr>
+                                        <tr>
+                                            <th>Effective APR (calculated)</th>
+                                            <td>{{ acct.effective_apr|decimal_to_percent</td>
+                                        </tr>
                                         <tr>
                                             <th>Interest Class</th>
                                             <td>{{ acct.interest_class_name }}</td>
diff --git a/biweeklybudget/interest.py b/biweeklybudget/interest.py
index 2da2c19b..3fb46bb2 100644
--- a/biweeklybudget/interest.py
+++ b/biweeklybudget/interest.py
@@ -110,7 +110,7 @@ def _make_statements(self, accounts):
             icharge = acct.latest_ofx_interest_charge
             istmt = icharge.first_statement_by_date
             icls = INTEREST_CALCULATION_NAMES[acct.interest_class_name]['cls'](
-                acct.apr
+                acct.effective_apr
             )
             bill_period = _BillingPeriod(icharge.date_posted.date())
             min_pay_cls = MIN_PAYMENT_FORMULA_NAMES[
diff --git a/biweeklybudget/models/account.py b/biweeklybudget/models/account.py
index fd165106..b64c3fe9 100644
--- a/biweeklybudget/models/account.py
+++ b/biweeklybudget/models/account.py
@@ -115,6 +115,9 @@ class Account(Base, ModelAsDict):
     #: Finance rate (APR) for credit accounts
     apr = Column(Numeric(precision=5, scale=4))
 
+    #: Margin added to the US Prime Rate to determine APR, for credit accounts
+    prime_rate_margin = Column(Numeric(precision=5, scale=4))
+
     #: Name of the :py:class:`biweeklybudget.interest._InterestCalculation`
     #: subclass used to calculate interest for this account.
     interest_class_name = Column(String(70))
@@ -310,3 +313,15 @@ def latest_ofx_interest_charge(self):
         logger.debug('Latest OFX Interest Charge for account %s: %s',
                      self, t)
         return t
+
+    @property
+    def effective_apr(self):
+        """
+        Return the effective APR for a credit account. If
+        :py:attr:`~.prime_rate_margin` is not Null, return it. Otherwise, return
+        :py:attr:`~.apr`.
+
+        :return: Effective account APR
+        :rtype: decimal.Decimal
+        """
+        return self.apr