diff --git a/generic/forms.py b/generic/forms.py
index 613ca8a8..acc489a2 100755
--- a/generic/forms.py
+++ b/generic/forms.py
@@ -2,6 +2,7 @@ from django.forms import (
     Form,
     ModelForm,
     ModelMultipleChoiceField,
+    MultipleChoiceField,
     ModelChoiceField,
     ChoiceField,
     CharField,
@@ -291,6 +292,43 @@ class ExamGroupsFormMixin(ModelForm):
         self.fields["user_user_groups"].widget.attrs["size"] = 8
 
 
+class ExamCollectionBulkAddGroupsForm(Form):
+    """Form used by the HTMX modal to bulk-add CID/User groups to an ExamCollection.
+
+    Accepts `user` kwarg in __init__ to limit available groups based on permissions
+    (mirrors behaviour of `ExamGroupsFormMixin`).
+    """
+    cid_user_groups = ModelMultipleChoiceField(required=False, queryset=CidUserGroup.objects.none(), label="CID User Groups")
+    user_user_groups = ModelMultipleChoiceField(required=False, queryset=UserUserGroup.objects.none(), label="User Groups")
+    EXAM_TYPE_CHOICES = [
+        ("all", "All"),
+        ("anatomy", "Anatomy"),
+        ("longs", "Longs"),
+        ("rapids", "Rapids"),
+        ("shorts", "Shorts"),
+        ("physics", "Physics"),
+        ("sbas", "SBAs"),
+    ]
+    exam_types = MultipleChoiceField(required=False, choices=EXAM_TYPE_CHOICES, label="Exam types (leave empty for all)")
+
+    def __init__(self, *args, user=None, **kwargs):
+        # keep compatibility with other forms that pass user as kwarg
+        # This is a plain Form (not a ModelForm) so call Form.__init__
+        Form.__init__(self, *args, **kwargs)
+        # choose queryset depending on permissions
+        if user and (user.is_superuser or user.groups.filter(name="cid_user_manager").exists()):
+            cid_qs = CidUserGroup.objects.filter(archive=False)
+            user_qs = UserUserGroup.objects.filter(archive=False)
+        else:
+            cid_qs = CidUserGroup.objects.filter(archive=False, open_access=True)
+            user_qs = UserUserGroup.objects.filter(archive=False, open_access=True)
+
+        self.fields["cid_user_groups"].queryset = cid_qs
+        self.fields["user_user_groups"].queryset = user_qs
+        self.fields["cid_user_groups"].widget.attrs["size"] = 8
+        self.fields["user_user_groups"].widget.attrs["size"] = 8
+
+
 class ExaminationForm(ModelForm):
     def __init__(self, *args, **kwargs):
         # Where is this coming from?
diff --git a/generic/models.py b/generic/models.py
index 2182a030..49b6b20e 100644
--- a/generic/models.py
+++ b/generic/models.py
@@ -1946,6 +1946,92 @@ class ExamCollection(models.Model, AuthorMixin):
                 exam.add_markers(users)
         #return True
 
+    def bulk_add_user_user_groups(self, groups, exam_types: None | list[str] = None) -> int:
+        """Bulk-add one or more UserUserGroup objects (or PKs) to all exams in this
+        collection.
+
+        Args:
+            groups: iterable of UserUserGroup instances or an iterable of PKs (ints),
+                or a Django QuerySet of UserUserGroup.
+            exam_types: optional list of exam type keys to limit the operation. Keys
+                are the same as returned by `get_exams()` (e.g. 'physics', 'anatomy').
+
+        Returns:
+            Number of exams that were updated (int).
+
+        Note: permission checks are not performed here; callers should ensure the
+        current user is allowed to modify these exams.
+        """
+        # import locally to avoid circular import surprises when module is imported
+        UserUserGroup = globals().get("UserUserGroup")
+        if UserUserGroup is None:
+            raise RuntimeError("UserUserGroup model not available")
+
+        # Normalize groups to a list of model instances
+        if groups is None:
+            return 0
+
+        # If groups is a queryset or list of model instances, materialize it
+        try:
+            # QuerySet-ish
+            groups_qs = list(groups)
+        except TypeError:
+            # single value provided
+            groups_qs = [groups]
+
+        # If provided values were ints (PKs), resolve them to model instances
+        if groups_qs and all(isinstance(g, int) for g in groups_qs):
+            groups_qs = list(UserUserGroup.objects.filter(pk__in=groups_qs))
+
+        if not groups_qs:
+            return 0
+
+        updated = 0
+        for exam_type, exams in self.get_exams().items():
+            if exam_types is not None and exam_type not in exam_types:
+                continue
+
+            for exam in exams:
+                # Each exam model exposes a `user_user_groups` ManyToManyField
+                exam.user_user_groups.add(*groups_qs)
+                updated += 1
+
+        return updated
+
+    def bulk_add_cid_user_groups(self, groups, exam_types: None | list[str] = None) -> int:
+        """Bulk-add one or more CidUserGroup objects (or PKs) to all exams in this
+        collection. Returns number of exams updated.
+        """
+        CidUserGroup = globals().get("CidUserGroup")
+        if CidUserGroup is None:
+            raise RuntimeError("CidUserGroup model not available")
+
+        if groups is None:
+            return 0
+
+        try:
+            groups_qs = list(groups)
+        except TypeError:
+            groups_qs = [groups]
+
+        if groups_qs and all(isinstance(g, int) for g in groups_qs):
+            groups_qs = list(CidUserGroup.objects.filter(pk__in=groups_qs))
+
+        if not groups_qs:
+            return 0
+
+        updated = 0
+        for exam_type, exams in self.get_exams().items():
+            if exam_types is not None and exam_type not in exam_types:
+                continue
+
+            for exam in exams:
+                # Each exam model exposes a `cid_user_groups` ManyToManyField
+                exam.cid_user_groups.add(*groups_qs)
+                updated += 1
+
+        return updated
+
 
 #class Presentation(models.Model, AuthorMixin):
 #
diff --git a/generic/templates/generic/examcollection_detail.html b/generic/templates/generic/examcollection_detail.html
index 306ab4bb..2f91165e 100755
--- a/generic/templates/generic/examcollection_detail.html
+++ b/generic/templates/generic/examcollection_detail.html
@@ -86,9 +86,13 @@
         {% endif %}
 
         <br/>
-        <div id="add-user">
-        <button hx-get="{% url 'generic:exam_collection_add_author' object.pk %}" hx-target="#add-user" hx-swap="innerHTML">Add author to all exams</button>
-        </div>
+    <div id="bulk-add-groups">
+    <button class="btn-sm" hx-get="{% url 'generic:exam_collection_bulk_add_groups' object.pk %}" hx-target="#bulk-add-groups" hx-swap="innerHTML">Add groups to exams</button>
+    </div>
+
+    <div id="add-user">
+    <button hx-get="{% url 'generic:exam_collection_add_author' object.pk %}" hx-target="#add-user" hx-swap="innerHTML">Add author to all exams</button>
+    </div>
 
     {% include 'exam_overview_js.html' %}
 
diff --git a/generic/templates/generic/partials/examcollection_bulk_add_groups_form.html b/generic/templates/generic/partials/examcollection_bulk_add_groups_form.html
new file mode 100644
index 00000000..675185ab
--- /dev/null
+++ b/generic/templates/generic/partials/examcollection_bulk_add_groups_form.html
@@ -0,0 +1,19 @@
+<form hx-post="{% url 'generic:exam_collection_bulk_add_groups' collection.pk %}" hx-target="#bulk-add-groups" hx-swap="innerHTML" class="bulk-add-groups-form">
+    {% csrf_token %}
+    <div>
+        {{ form.cid_user_groups.label_tag }}<br/>
+        {{ form.cid_user_groups }}
+    </div>
+    <div>
+        {{ form.user_user_groups.label_tag }}<br/>
+        {{ form.user_user_groups }}
+    </div>
+    <div>
+        {{ form.exam_types.label_tag }}<br/>
+        {{ form.exam_types }}
+    </div>
+    <div class="mt-2">
+        <button type="submit" class="btn btn-primary btn-sm">Add groups</button>
+        <button type="button" class="btn btn-secondary btn-sm" hx-get="{% url 'generic:examcollection_detail' collection.pk %}" hx-target="#bulk-add-groups" hx-swap="innerHTML">Cancel</button>
+    </div>
+</form>
diff --git a/generic/templates/generic/partials/examcollection_bulk_add_groups_result.html b/generic/templates/generic/partials/examcollection_bulk_add_groups_result.html
new file mode 100644
index 00000000..4a6633ff
--- /dev/null
+++ b/generic/templates/generic/partials/examcollection_bulk_add_groups_result.html
@@ -0,0 +1,11 @@
+<div class="bulk-add-result">
+    {% if error %}
+        <div class="alert alert-danger">Error: {{ error }}</div>
+    {% else %}
+        <p>Added user groups to {{ total_user }} exams.</p>
+        <p>Added CID groups to {{ total_cid }} exams.</p>
+    {% endif %}
+    <div class="mt-2">
+        <button class="btn btn-sm btn-outline-primary" hx-get="{% url 'generic:exam_collection_bulk_add_groups' collection.pk %}" hx-target="#bulk-add-groups" hx-swap="innerHTML">Add more</button>
+    </div>
+</div>
diff --git a/generic/urls.py b/generic/urls.py
index fadc802c..6facc40f 100755
--- a/generic/urls.py
+++ b/generic/urls.py
@@ -255,6 +255,7 @@ urlpatterns = [
         name="examcollection_delete",
     ),
     path("collection/<int:collection_id>/add_author", views.exam_collection_add_author, name="exam_collection_add_author"),
+    path("collection/<int:collection_id>/bulk_add_groups", views.exam_collection_bulk_add_groups, name="exam_collection_bulk_add_groups"),
     path("collection/<int:collection_id>/add_marker/<str:exam_type>", views.exam_collection_add_marker, name="exam_collection_add_marker"),
     path(
         "share_with_supervisor_toggle/<int:pk>/",
diff --git a/generic/views.py b/generic/views.py
index 9d4df40b..81e96b8e 100644
--- a/generic/views.py
+++ b/generic/views.py
@@ -86,6 +86,7 @@ from .forms import (
     UserUserForm,
     UserUserGroupForm,
     UsersAutocompleteForm,  # Added import
+    ExamCollectionBulkAddGroupsForm,
 )
 
 from .models import (
@@ -144,6 +145,7 @@ from shorts.models import Question as ShortsQuestion, ExamQuestionDetail as Shor
 
 from django.db.models import Case, When
 from django.conf import settings
+from django.db import transaction
 
 from datetime import datetime
 from django.utils import timezone
@@ -378,6 +380,49 @@ def create_examination(request):
     )
 
 
+@login_required
+@user_passes_test(lambda u: u.is_superuser or u.groups.filter(name="cid_user_manager").exists())
+def exam_collection_bulk_add_groups(request, collection_id):
+    """HTMX endpoint: show form (GET) and process bulk-adding of CID/User groups (POST).
+
+    Renders small partials suitable for HTMX swaps.
+    """
+    collection = get_object_or_404(ExamCollection, pk=collection_id)
+
+    if request.method == "GET":
+        form = ExamCollectionBulkAddGroupsForm(user=request.user)
+        return render(request, "generic/partials/examcollection_bulk_add_groups_form.html", {"form": form, "collection": collection})
+
+    # POST
+    form = ExamCollectionBulkAddGroupsForm(request.POST, user=request.user)
+    if not form.is_valid():
+        return render(request, "generic/partials/examcollection_bulk_add_groups_form.html", {"form": form, "collection": collection})
+
+    cid_groups = form.cleaned_data.get("cid_user_groups")
+    user_groups = form.cleaned_data.get("user_user_groups")
+    exam_types = form.cleaned_data.get("exam_types")
+    # If 'all' is selected (or no selection), treat as None -> all exams
+    if exam_types:
+        if "all" in exam_types:
+            exam_types = None
+    else:
+        exam_types = None
+
+    total_user = 0
+    total_cid = 0
+    try:
+        with transaction.atomic():
+            if user_groups:
+                total_user = collection.bulk_add_user_user_groups(user_groups, exam_types=exam_types)
+            if cid_groups:
+                total_cid = collection.bulk_add_cid_user_groups(cid_groups, exam_types=exam_types)
+    except Exception as e:
+        # render an error fragment
+        return render(request, "generic/partials/examcollection_bulk_add_groups_result.html", {"error": str(e), "collection": collection})
+
+    return render(request, "generic/partials/examcollection_bulk_add_groups_result.html", {"total_user": total_user, "total_cid": total_cid, "collection": collection})
+
+
 @login_required
 @user_passes_test(lambda u: u.is_superuser)
 def examination_detail(request, pk):