diff --git a/src/registrar/tests/test_views_members_json.py b/src/registrar/tests/test_views_members_json.py
index b094ba2a4..a97a517e2 100644
--- a/src/registrar/tests/test_views_members_json.py
+++ b/src/registrar/tests/test_views_members_json.py
@@ -222,29 +222,43 @@ class GetPortfolioMembersJsonTest(MockEppLib, WebTest):
             roles=[UserPortfolioRoleChoices.ORGANIZATION_ADMIN],
         )
 
+        # create domain for which user is manager and domain in portfolio
         domain = Domain.objects.create(
             name="somedomain1.com",
         )
-
         DomainInformation.objects.create(
             creator=self.user,
             domain=domain,
             portfolio=self.portfolio,
         )
-
         UserDomainRole.objects.create(
             user=self.user,
             domain=domain,
             role=UserDomainRole.Roles.MANAGER,
         )
 
+        # create domain for which user is manager and domain not in portfolio
+        domain2 = Domain.objects.create(
+            name="somedomain2.com",
+        )
+        DomainInformation.objects.create(
+            creator=self.user,
+            domain=domain2,
+        )
+        UserDomainRole.objects.create(
+            user=self.user,
+            domain=domain2,
+            role=UserDomainRole.Roles.MANAGER,
+        )
+
         response = self.app.get(reverse("get_portfolio_members_json"), params={"portfolio": self.portfolio.id})
         self.assertEqual(response.status_code, 200)
         data = response.json
 
-        # Check if the domain appears in the response JSON
+        # Check if the domain appears in the response JSON and that domain2 does not
         domain_names = [domain_name for member in data["members"] for domain_name in member.get("domain_names", [])]
         self.assertIn("somedomain1.com", domain_names)
+        self.assertNotIn("somedomain2.com", domain_names)
 
     def test_get_portfolio_invited_json_with_domains(self):
         """Test that portfolio invited members are returned properly for an authenticated user and the response includes
@@ -259,28 +273,41 @@ class GetPortfolioMembersJsonTest(MockEppLib, WebTest):
             ],
         )
 
+        # create a domain in the portfolio
         domain = Domain.objects.create(
             name="somedomain1.com",
         )
-
         DomainInformation.objects.create(
             creator=self.user,
             domain=domain,
             portfolio=self.portfolio,
         )
-
         DomainInvitation.objects.create(
             email=self.email6,
             domain=domain,
         )
 
+        # create a domain not in the portfolio
+        domain2 = Domain.objects.create(
+            name="somedomain2.com",
+        )
+        DomainInformation.objects.create(
+            creator=self.user,
+            domain=domain2,
+        )
+        DomainInvitation.objects.create(
+            email=self.email6,
+            domain=domain2,
+        )
+
         response = self.app.get(reverse("get_portfolio_members_json"), params={"portfolio": self.portfolio.id})
         self.assertEqual(response.status_code, 200)
         data = response.json
 
-        # Check if the domain appears in the response JSON
+        # Check if the domain appears in the response JSON and domain2 does not
         domain_names = [domain_name for member in data["members"] for domain_name in member.get("domain_names", [])]
         self.assertIn("somedomain1.com", domain_names)
+        self.assertNotIn("somedomain2.com", domain_names)
 
     def test_pagination(self):
         """Test that pagination works properly when there are more members than page size."""
diff --git a/src/registrar/views/portfolio_members_json.py b/src/registrar/views/portfolio_members_json.py
index 11c650cef..e78403659 100644
--- a/src/registrar/views/portfolio_members_json.py
+++ b/src/registrar/views/portfolio_members_json.py
@@ -93,7 +93,8 @@ def initial_permissions_search(portfolio):
                     output_field=CharField(),
                 ),
                 distinct=True,
-                filter=Q(user__permissions__domain__isnull=False),  # filter out null values
+                filter=Q(user__permissions__domain__isnull=False)  # filter out null values
+                & Q(user__permissions__domain__domain_info__portfolio=portfolio),  # only include domains in portfolio
             ),
             source=Value("permission", output_field=CharField()),
         )
@@ -121,10 +122,11 @@ class ArrayRemove(Func):
 
 def initial_invitations_search(portfolio):
     """Perform initial invitations search and get related DomainInvitation data based on the email."""
-    # Get DomainInvitation query for matching email
-    domain_invitations = DomainInvitation.objects.filter(email=OuterRef("email")).annotate(
-        domain_info=Concat(F("domain__id"), Value(":"), F("domain__name"), output_field=CharField())
-    )
+    # Get DomainInvitation query for matching email and for the portfolio
+    domain_invitations = DomainInvitation.objects.filter(
+        email=OuterRef("email"),  # Check if email matches the OuterRef("email")
+        domain__domain_info__portfolio=portfolio,  # Check if the domain's portfolio matches the given portfolio
+    ).annotate(domain_info=Concat(F("domain__id"), Value(":"), F("domain__name"), output_field=CharField()))
     # PortfolioInvitation query
     invitations = PortfolioInvitation.objects.filter(portfolio=portfolio)
     invitations = invitations.annotate(