diff --git a/src/registrar/models/domain_invitation.py b/src/registrar/models/domain_invitation.py
index 1ad150e4a..59157349f 100644
--- a/src/registrar/models/domain_invitation.py
+++ b/src/registrar/models/domain_invitation.py
@@ -1,5 +1,7 @@
 """People are invited by email to administer domains."""
 
+import logging
+
 from django.contrib.auth import get_user_model
 from django.db import models, IntegrityError
 
@@ -9,6 +11,9 @@ from .utility.time_stamped_model import TimeStampedModel
 from .user_domain_role import UserDomainRole
 
 
+logger = logging.getLogger(__name__)
+
+
 class DomainInvitation(TimeStampedModel):
     INVITED = "invited"
     RETRIEVED = "retrieved"
@@ -39,7 +44,11 @@ class DomainInvitation(TimeStampedModel):
 
     @transition(field="status", source=INVITED, target=RETRIEVED)
     def retrieve(self):
-        """When an invitation is retrieved, create the corresponding permission."""
+        """When an invitation is retrieved, create the corresponding permission.
+
+        Raises:
+            RuntimeError if no matching user can be found.
+        """
 
         # get a user with this email address
         User = get_user_model()
@@ -54,12 +63,12 @@ class DomainInvitation(TimeStampedModel):
 
         # and create a role for that user on this domain
         try:
-            UserDomainRole.objects.create(
+            role = UserDomainRole.objects.get(
                 user=user, domain=self.domain, role=UserDomainRole.Roles.ADMIN
             )
-        except IntegrityError:
-            # should not happen because this user shouldn't retrieve this invitation
-            # more than once.
-            raise RuntimeError(
-                "Invitation would create a role that already exists for this user."
-            )
+        except UserDomainRole.DoesNotExist:
+            UserDomainRole.objects.create(user=user, domain=self.domain, role=UserDomainRole.Roles.ADMIN)
+        else:
+            # something strange happened and this role already existed when
+            # the invitation was retrieved. Log that this occurred.
+            logger.warn("Invitation %s was retrieved for a role that already exists.", self)
diff --git a/src/registrar/models/user.py b/src/registrar/models/user.py
index fb51af30c..3448d712d 100644
--- a/src/registrar/models/user.py
+++ b/src/registrar/models/user.py
@@ -1,3 +1,5 @@
+import logging
+
 from django.contrib.auth.models import AbstractUser
 from django.db import models
 
@@ -6,6 +8,9 @@ from .domain_invitation import DomainInvitation
 from phonenumber_field.modelfields import PhoneNumberField  # type: ignore
 
 
+logger = logging.getLogger(__name__)
+
+
 class User(AbstractUser):
     """
     A custom user model that performs identically to the default user model
@@ -43,5 +48,11 @@ class User(AbstractUser):
         for invitation in DomainInvitation.objects.filter(
             email=self.email, status=DomainInvitation.INVITED
         ):
-            invitation.retrieve()
-            invitation.save()
+            try:
+                invitation.retrieve()
+                invitation.save()
+            except RuntimeError:
+                # retrieving should not fail because of a missing user, but
+                # if it does fail, log the error so a new user can continue
+                # logging in
+                logger.warn("Failed to retrieve invitation %s", invitation,  exc_info=True)
diff --git a/src/registrar/tests/test_models.py b/src/registrar/tests/test_models.py
index b60898e50..5649172b2 100644
--- a/src/registrar/tests/test_models.py
+++ b/src/registrar/tests/test_models.py
@@ -177,6 +177,9 @@ class TestInvitations(TestCase):
         )
         self.user, _ = User.objects.get_or_create(email=self.email)
 
+        # clean out the roles each time
+        UserDomainRole.objects.all().delete()
+
     def test_retrieval_creates_role(self):
         self.invitation.retrieve()
         self.assertTrue(UserDomainRole.objects.get(user=self.user, domain=self.domain))
@@ -187,11 +190,13 @@ class TestInvitations(TestCase):
         with self.assertRaises(RuntimeError):
             self.invitation.retrieve()
 
-    def test_retrieve_existing_role_error(self):
+    def test_retrieve_existing_role_no_error(self):
         # make the overlapping role
-        UserDomainRole.objects.get_or_create(user=self.user, domain=self.domain)
-        with self.assertRaises(RuntimeError):
+        UserDomainRole.objects.get_or_create(user=self.user, domain=self.domain, role=UserDomainRole.Roles.ADMIN)
+        # this is not an error but does produce a console warning
+        with less_console_noise():
             self.invitation.retrieve()
+        self.assertEqual(self.invitation.status, DomainInvitation.RETRIEVED)
 
     def test_retrieve_on_first_login(self):
         """A new user's first_login callback retrieves their invitations."""