diff --git a/openquake/hazardlib/gsim/atkinson_macias_2009.py b/openquake/hazardlib/gsim/atkinson_macias_2009.py
index 38430a87a5f..17a87b81275 100644
--- a/openquake/hazardlib/gsim/atkinson_macias_2009.py
+++ b/openquake/hazardlib/gsim/atkinson_macias_2009.py
@@ -25,6 +25,7 @@
 from openquake.hazardlib.gsim.base import GMPE, CoeffsTable
 from openquake.hazardlib import const
 from openquake.hazardlib.imt import PGA, SA
+from openquake.hazardlib.gsim.mgmpe.cb14_basin_term import _get_cb14_basin_term
 
 
 def _get_distance_term(C, rrup, mag):
@@ -77,6 +78,12 @@ class AtkinsonMacias2009(GMPE):
     #: Required distance measure is rupture distance
     REQUIRES_DISTANCES = {'rrup'}
 
+    def __init__(self, cb14_basin_term=False):
+        if cb14_basin_term:
+            self.REQUIRES_SITES_PARAMETERS = frozenset(
+            self.REQUIRES_SITES_PARAMETERS | {'z2pt5'})
+        self.cb14_basin_term = cb14_basin_term
+        
     def compute(self, ctx: np.recarray, imts, mean, sig, tau, phi):
         """
         See :meth:`superclass method
@@ -89,7 +96,11 @@ def compute(self, ctx: np.recarray, imts, mean, sig, tau, phi):
                      _get_distance_term(C, ctx.rrup, ctx.mag))
             # Convert mean from cm/s and cm/s/s and from common logarithm to
             # natural logarithm
-            mean[m] = np.log((10.0 ** (imean - 2.0)) / g)
+            ln_mean = np.log((10.0 ** (imean - 2.0)) / g)
+            # Apply CB14 basin term if specified
+            if self.cb14_basin_term:
+                ln_mean += _get_cb14_basin_term(imt, ctx)
+            mean[m] = ln_mean
             sig[m] = np.log(10.0 ** C["sigma"])
 
     COEFFS = CoeffsTable(sa_damping=5, table="""
diff --git a/openquake/hazardlib/gsim/kuehn_2020.py b/openquake/hazardlib/gsim/kuehn_2020.py
index 746ded0abd2..c734fbf6298 100644
--- a/openquake/hazardlib/gsim/kuehn_2020.py
+++ b/openquake/hazardlib/gsim/kuehn_2020.py
@@ -647,8 +647,7 @@ class KuehnEtAl2020SInter(GMPE):
     m_b: The magnitude scaling breakpoint. This term is defined for each region
          and tectonic region type, but this can also be over-ridden by the user
 
-    :param bool m9_basin_term: Apply the M9 basin term instead of the GMM's
-                               native basin term
+    :param bool m9_basin_term: Apply the M9 basin adjustment
 
     :param bool usgs_basin_scaling: Scaling factor to be applied to basin term
                                     based on USGS basin model
diff --git a/openquake/hazardlib/gsim/mgmpe/cb14_basin_term.py b/openquake/hazardlib/gsim/mgmpe/cb14_basin_term.py
index acad2d59e72..9e0f71dbb33 100644
--- a/openquake/hazardlib/gsim/mgmpe/cb14_basin_term.py
+++ b/openquake/hazardlib/gsim/mgmpe/cb14_basin_term.py
@@ -25,7 +25,7 @@
 from openquake.hazardlib.gsim.campbell_bozorgnia_2014 import CampbellBozorgnia2014
 
 
-def _get_cb14_basin_term(ctx, C, jpn_flag=False):
+def _get_cb14_basin_term(imt, ctx, jpn_flag=False):
     """
     Get the basin response term defined in equation 20 of the Campbell and 
     Bozorgnia (2014) GMM paper.
@@ -33,6 +33,7 @@ def _get_cb14_basin_term(ctx, C, jpn_flag=False):
     Currently the global basin term is provided (i.e. the Japan-regionalised
     basin term is for now turned off).
     """
+    C = CampbellBozorgnia2014.COEFFS[imt]
     z2pt5 = ctx.z2pt5
     fb = np.zeros(len(z2pt5))
     idx = z2pt5 < 1.0
@@ -81,5 +82,4 @@ def compute(self, ctx: np.recarray, imts, mean, sig, tau, phi):
         """
         self.gmpe.compute(ctx, imts, mean, sig, tau, phi)
         for m, imt in enumerate(imts):
-             C = CampbellBozorgnia2014.COEFFS[imt]
-             mean[m] += _get_cb14_basin_term(ctx, C)
\ No newline at end of file
+             mean[m] += _get_cb14_basin_term(ctx)
\ No newline at end of file
diff --git a/openquake/hazardlib/gsim/parker_2020.py b/openquake/hazardlib/gsim/parker_2020.py
index 3313dadd920..b94c31a3d9b 100644
--- a/openquake/hazardlib/gsim/parker_2020.py
+++ b/openquake/hazardlib/gsim/parker_2020.py
@@ -375,8 +375,7 @@ class ParkerEtAl2020SInter(GMPE):
                                   "AK", "Cascadia", "CAM_S", "CAM_N", "JP_Pac",
                                   "JP_Phi", "SA_N", "SA_S", "TW_W", "TW_E")
     :param str basin: Choice of basin region ("Out" or "Seattle")
-    :param bool m9_basin_term: Apply the M9 basin term instead of the GMM's
-                               native basin term
+    :param bool m9_basin_term: Apply the M9 basin term adjustment
     :param bool usgs_basin_scaling: Scaling factor to be applied to basin term
                                     based on USGS basin model
     :param float sigma_mu_epsilon: Number of standard deviations to multiply
@@ -406,6 +405,8 @@ class ParkerEtAl2020SInter(GMPE):
     #: Required distance measure is closest distance to rupture, for
     #: interface events
     REQUIRES_DISTANCES = {'rrup'}
+
+    # Other required attributes
     REQUIRES_ATTRIBUTES = {'region', 'saturation_region', 'basin',
                            'm9_basin_term' 'usgs_basin_scaling',
                            'sigma_mu_epsilon'}
@@ -477,8 +478,14 @@ def compute(self, ctx: np.recarray, imts, mean, sig, tau, phi):
             if self.m9_basin_term and imt != PGV:
                 if imt.period >= 1.9:
                     m9_adj = _get_adjusted_m9_basin_term(C, ctx.z2pt5)
-                    fb[ctx.z2pt5 >= 6.0] += m9_adj[ctx.z2pt5 >= 6.0]
-                    
+                    if fb != 0.0:
+                        fb[ctx.z2pt5 >= 6.0] += m9_adj[ctx.z2pt5 >= 6.0]
+                    else:
+                        fb = m9_adj # fb is zero if no region (no basin) thus
+                                    # just take the adjusted m9 term instead
+                                    # for the basin amplification given has
+                                    # been specified by user
+
             # Now get the mean with basin term added
             mean[m] = pre_baf_mean + (fb * usgs_baf)