diff --git a/litellm/proxy/management_endpoints/budget_management_endpoints.py b/litellm/proxy/management_endpoints/budget_management_endpoints.py
index 62a24109dbb..81a607aaa43 100644
--- a/litellm/proxy/management_endpoints/budget_management_endpoints.py
+++ b/litellm/proxy/management_endpoints/budget_management_endpoints.py
@@ -14,6 +14,7 @@ All /budget management endpoints
 #### BUDGET TABLE MANAGEMENT ####
 import math
 from collections.abc import Mapping
+from types import MappingProxyType
 from typing import Final
 
 from fastapi import APIRouter, Depends, HTTPException
@@ -176,6 +177,10 @@ async def update_budget(
     recomputed_reset_at: Final = (
         {"budget_reset_at": get_budget_reset_time(budget_duration=budget_obj.budget_duration)}
         if budget_obj.budget_duration is not None and "budget_reset_at" not in budget_obj.model_fields_set
+        else MappingProxyType({"budget_reset_at": None})
+        if "budget_duration" in budget_obj.model_fields_set
+        and budget_obj.budget_duration is None
+        and "budget_reset_at" not in budget_obj.model_fields_set
         else {}
     )
 
diff --git a/litellm/proxy/management_endpoints/internal_user_endpoints.py b/litellm/proxy/management_endpoints/internal_user_endpoints.py
index 10c11119006..000b7f874ee 100644
--- a/litellm/proxy/management_endpoints/internal_user_endpoints.py
+++ b/litellm/proxy/management_endpoints/internal_user_endpoints.py
@@ -1254,8 +1254,8 @@ def _update_internal_user_params(data_json: dict, data: UpdateUserRequest | Upda
     fields_set: Final = data.fields_set() if hasattr(data, "fields_set") else set()
 
     for k, v in data_json.items():
-        if k == "max_budget":
-            if "max_budget" in fields_set:
+        if k in ("max_budget", "budget_duration"):
+            if k in fields_set:
                 non_default_values[k] = v
         elif k == "model_max_budget":
             if k in fields_set:
@@ -1283,8 +1283,10 @@ def _update_internal_user_params(data_json: dict, data: UpdateUserRequest | Upda
         from litellm.proxy.common_utils.timezone_utils import get_budget_reset_time
 
         validate_budget_duration(non_default_values["budget_duration"])
-        non_default_values["budget_reset_at"] = get_budget_reset_time(
-            budget_duration=non_default_values["budget_duration"]
+        non_default_values["budget_reset_at"] = (
+            get_budget_reset_time(budget_duration=non_default_values["budget_duration"])
+            if non_default_values["budget_duration"] is not None
+            else None
         )
 
     if "max_budget" not in non_default_values:
diff --git a/litellm/proxy/management_endpoints/tag_management_endpoints.py b/litellm/proxy/management_endpoints/tag_management_endpoints.py
index b74aa1a4e16..ab33d4bd766 100644
--- a/litellm/proxy/management_endpoints/tag_management_endpoints.py
+++ b/litellm/proxy/management_endpoints/tag_management_endpoints.py
@@ -438,6 +438,7 @@ async def update_tag(
             user_api_key_dict=user_api_key_dict,
             prisma_client=prisma_client,
             litellm_proxy_admin_name=litellm_proxy_admin_name,
+            budget_duration_cleared="budget_duration" in tag.model_fields_set and tag.budget_duration is None,
         )
 
         # Get model names for model_info
diff --git a/litellm/proxy/management_helpers/utils.py b/litellm/proxy/management_helpers/utils.py
index e2d7262fb69..f3bd4b0f6dd 100644
--- a/litellm/proxy/management_helpers/utils.py
+++ b/litellm/proxy/management_helpers/utils.py
@@ -3,6 +3,7 @@
 from collections.abc import Callable, Mapping, MutableMapping, Sequence
 from datetime import datetime
 from functools import wraps
+from types import MappingProxyType
 from typing import Any, Final, Protocol
 
 from fastapi import HTTPException, Request
@@ -180,6 +181,7 @@ async def handle_budget_for_entity(
     user_api_key_dict: UserAPIKeyAuth,
     prisma_client: PrismaClient,
     litellm_proxy_admin_name: str,
+    budget_duration_cleared: bool = False,
 ) -> str | None:
     """
     Common helper to handle budget creation/updates for entities (organizations, tags, etc).
@@ -208,7 +210,14 @@ async def handle_budget_for_entity(
 
     # Extract budget fields from data
     _json_data: Final = data.model_dump(exclude_none=True) if hasattr(data, "model_dump") else data
-    _budget_data: Final = {k: v for k, v in _json_data.items() if k in budget_params}
+    _budget_data: Final = MappingProxyType(
+        {
+            k: _json_data.get(k)
+            for k in budget_params
+            if k in _json_data
+            or (k == "budget_duration" and existing_budget_id is not None and budget_duration_cleared)
+        }
+    )
 
     # Check if budget_id is explicitly provided in the data
     data_budget_id: Final[str | None] = getattr(data, "budget_id", None)
diff --git a/tests/test_litellm/proxy/management_endpoints/test_budget_endpoints.py b/tests/test_litellm/proxy/management_endpoints/test_budget_endpoints.py
index 79d62f772bd..4b6815d7552 100644
--- a/tests/test_litellm/proxy/management_endpoints/test_budget_endpoints.py
+++ b/tests/test_litellm/proxy/management_endpoints/test_budget_endpoints.py
@@ -340,7 +340,8 @@ async def test_update_budget_recomputes_reset_at_when_duration_changes(
 
 
 @pytest.mark.asyncio
-async def test_update_budget_preserves_explicit_reset_at(client_and_mocks):
+@pytest.mark.parametrize("budget_duration", ["1d", None])
+async def test_update_budget_preserves_explicit_reset_at(client_and_mocks, budget_duration):
     """An explicit budget_reset_at from the caller always wins over recompute."""
     client, _, mock_table = client_and_mocks
     captured = _capture_update_data(mock_table)
@@ -350,7 +351,7 @@ async def test_update_budget_preserves_explicit_reset_at(client_and_mocks):
         "/budget/update",
         json={
             "budget_id": "budget_explicit_reset",
-            "budget_duration": "1d",
+            "budget_duration": budget_duration,
             "budget_reset_at": explicit.isoformat(),
         },
     )
@@ -377,8 +378,7 @@ async def test_update_budget_without_duration_leaves_reset_at_untouched(
 
 
 @pytest.mark.asyncio
-async def test_update_budget_duration_none_does_not_recompute(client_and_mocks):
-    """Clearing budget_duration (explicit null) must not recompute against a None duration."""
+async def test_update_budget_duration_none_clears_obsolete_reset(client_and_mocks):
     client, _, mock_table = client_and_mocks
     captured = _capture_update_data(mock_table)
 
@@ -389,7 +389,7 @@ async def test_update_budget_duration_none_does_not_recompute(client_and_mocks):
     assert resp.status_code == 200, resp.text
 
     assert "budget_duration" in captured and captured["budget_duration"] is None
-    assert "budget_reset_at" not in captured
+    assert captured["budget_reset_at"] is None
 
 
 @pytest.mark.asyncio
diff --git a/tests/test_litellm/proxy/management_endpoints/test_internal_user_endpoints.py b/tests/test_litellm/proxy/management_endpoints/test_internal_user_endpoints.py
index 92b1ab1586d..0d8b19345f1 100644
--- a/tests/test_litellm/proxy/management_endpoints/test_internal_user_endpoints.py
+++ b/tests/test_litellm/proxy/management_endpoints/test_internal_user_endpoints.py
@@ -2097,6 +2097,22 @@ def test_update_internal_user_params_reset_max_budget_with_none():
     assert non_default_values["user_id"] == "test_user"
 
 
+def test_update_internal_user_params_explicit_duration_clear_overrides_role_default(monkeypatch):
+    import litellm
+
+    monkeypatch.setattr(litellm, "internal_user_budget_duration", "30d")
+    data = UpdateUserRequest(
+        user_id="duration-clear-test",
+        user_role=LitellmUserRoles.INTERNAL_USER,
+        budget_duration=None,
+    )
+
+    updated = _update_internal_user_params(data_json=data.model_dump(exclude_unset=True), data=data)
+
+    assert updated["budget_duration"] is None
+    assert updated["budget_reset_at"] is None
+
+
 def test_update_internal_user_params_ignores_other_nones():
     """
     Test that other fields are still filtered out if None
diff --git a/ui/litellm-dashboard/src/app/(dashboard)/models-and-endpoints/components/AccessGroupBudgetModal.tsx b/ui/litellm-dashboard/src/app/(dashboard)/models-and-endpoints/components/AccessGroupBudgetModal.tsx
index 8df2a6620f9..cf5cf78d08a 100644
--- a/ui/litellm-dashboard/src/app/(dashboard)/models-and-endpoints/components/AccessGroupBudgetModal.tsx
+++ b/ui/litellm-dashboard/src/app/(dashboard)/models-and-endpoints/components/AccessGroupBudgetModal.tsx
@@ -98,7 +98,11 @@ const AccessGroupBudgetModal: React.FC<AccessGroupBudgetModalProps> = ({
                 )}
               >
                 {({ id, value, onChange }) => (
-                  <BudgetDurationDropdown id={id} value={value || null} onChange={onChange} />
+                  <BudgetDurationDropdown
+                    id={id}
+                    value={value || null}
+                    onChange={(next) => onChange(next ?? undefined)}
+                  />
                 )}
               </FormField>
             </FieldGroup>
diff --git a/ui/litellm-dashboard/src/app/(dashboard)/tag-management/_components/components/CreateTagModal.tsx b/ui/litellm-dashboard/src/app/(dashboard)/tag-management/_components/components/CreateTagModal.tsx
index 6f6bdcb6fe4..adb5a167c35 100644
--- a/ui/litellm-dashboard/src/app/(dashboard)/tag-management/_components/components/CreateTagModal.tsx
+++ b/ui/litellm-dashboard/src/app/(dashboard)/tag-management/_components/components/CreateTagModal.tsx
@@ -143,7 +143,11 @@ const CreateTagModal: React.FC<CreateTagModalProps> = ({ visible, onCancel, onSu
                     )}
                   >
                     {({ id, value, onChange }) => (
-                      <BudgetDurationDropdown id={id} value={value ?? null} onChange={onChange} />
+                      <BudgetDurationDropdown
+                        id={id}
+                        value={value ?? null}
+                        onChange={(next) => onChange(next ?? undefined)}
+                      />
                     )}
                   </FormField>
                 </FieldGroup>
diff --git a/ui/litellm-dashboard/src/app/(dashboard)/tag-management/_components/tag_info.tsx b/ui/litellm-dashboard/src/app/(dashboard)/tag-management/_components/tag_info.tsx
index e8cb358c0cf..1648a99bb0e 100644
--- a/ui/litellm-dashboard/src/app/(dashboard)/tag-management/_components/tag_info.tsx
+++ b/ui/litellm-dashboard/src/app/(dashboard)/tag-management/_components/tag_info.tsx
@@ -28,7 +28,7 @@ const tagEditShape = {
   description: z.string().optional(),
   models: z.array(z.string()).optional(),
   max_budget: z.union([z.string(), z.number()]).optional(),
-  budget_duration: z.string().optional(),
+  budget_duration: z.string().nullish(),
 };
 
 const tagEditSchema = z.object(tagEditShape);
diff --git a/ui/litellm-dashboard/src/components/Teams.tsx b/ui/litellm-dashboard/src/components/Teams.tsx
index f0d21cc5350..dc531ea5dad 100644
--- a/ui/litellm-dashboard/src/components/Teams.tsx
+++ b/ui/litellm-dashboard/src/components/Teams.tsx
@@ -807,7 +807,7 @@ const Teams: React.FC<TeamProps> = ({ accessToken, userID, userRole, premiumUser
                         showNeverResets
                         placeholder={budgetDurationPlaceholder}
                         value={value}
-                        onChange={onChange}
+                        onChange={(next) => onChange(next ?? undefined)}
                       />
                     )}
                   </FormField>
diff --git a/ui/litellm-dashboard/src/components/common_components/budget_duration_dropdown.tsx b/ui/litellm-dashboard/src/components/common_components/budget_duration_dropdown.tsx
index 3c38907c597..40ee857634c 100644
--- a/ui/litellm-dashboard/src/components/common_components/budget_duration_dropdown.tsx
+++ b/ui/litellm-dashboard/src/components/common_components/budget_duration_dropdown.tsx
@@ -14,7 +14,7 @@ const DURATION_LABELS: Record<string, string> = {
 interface BudgetDurationDropdownProps {
   id?: string;
   value?: string | null;
-  onChange?: (value: string | undefined) => void;
+  onChange?: (value: string | null) => void;
   className?: string;
   style?: React.CSSProperties;
   placeholder?: string;
@@ -31,11 +31,7 @@ const BudgetDurationDropdown: React.FC<BudgetDurationDropdownProps> = ({
   showNeverResets = false,
 }) => {
   return (
-    <Select
-      items={DURATION_LABELS}
-      value={value || null}
-      onValueChange={(next: string | null) => onChange?.(next ?? undefined)}
-    >
+    <Select items={DURATION_LABELS} value={value || null} onValueChange={onChange}>
       <SelectTrigger id={id} className={`w-full ${className}`} style={style}>
         <SelectValue placeholder={placeholder} />
       </SelectTrigger>
diff --git a/ui/litellm-dashboard/src/components/organisms/create_key_button.tsx b/ui/litellm-dashboard/src/components/organisms/create_key_button.tsx
index 82580fd4667..b5789101f77 100644
--- a/ui/litellm-dashboard/src/components/organisms/create_key_button.tsx
+++ b/ui/litellm-dashboard/src/components/organisms/create_key_button.tsx
@@ -1021,7 +1021,7 @@ const CreateKey: React.FC<CreateKeyProps> = ({ team, teams, data, addKey, autoOp
                             value={control.value as string | null | undefined}
                             showNeverResets
                             placeholder="Not set"
-                            onChange={control.onChange}
+                            onChange={(next) => control.onChange(next ?? undefined)}
                           />
                         )}
                       </MountedFormField>
diff --git a/ui/litellm-dashboard/src/components/tag_management/types.tsx b/ui/litellm-dashboard/src/components/tag_management/types.tsx
index 3cf17545fd6..88dfa28204d 100644
--- a/ui/litellm-dashboard/src/components/tag_management/types.tsx
+++ b/ui/litellm-dashboard/src/components/tag_management/types.tsx
@@ -41,7 +41,7 @@ export interface TagUpdateRequest {
   soft_budget?: number;
   tpm_limit?: number;
   rpm_limit?: number;
-  budget_duration?: string;
+  budget_duration?: string | null;
 }
 
 export interface TagDeleteRequest {
diff --git a/ui/litellm-dashboard/src/components/team/EditMembership.tsx b/ui/litellm-dashboard/src/components/team/EditMembership.tsx
index 036c4f1cc0b..909b5d56c97 100644
--- a/ui/litellm-dashboard/src/components/team/EditMembership.tsx
+++ b/ui/litellm-dashboard/src/components/team/EditMembership.tsx
@@ -157,7 +157,7 @@ const MemberModal = <T extends BaseMember>({
               <BudgetDurationDropdown
                 id={id}
                 value={typeof value === "string" ? value : null}
-                onChange={(next) => onChange(next)}
+                onChange={(next) => onChange(mode === "add" ? next ?? undefined : next)}
               />
             );
           default:
diff --git a/ui/litellm-dashboard/src/components/team/TeamInfo.tsx b/ui/litellm-dashboard/src/components/team/TeamInfo.tsx
index 8e3a17c2622..ffc83d0165e 100644
--- a/ui/litellm-dashboard/src/components/team/TeamInfo.tsx
+++ b/ui/litellm-dashboard/src/components/team/TeamInfo.tsx
@@ -1467,7 +1467,9 @@ const TeamInfoView: React.FC<TeamInfoProps> = ({
                               showNeverResets
                               placeholder="Inherit team reset period"
                               value={value === null ? NEVER_RESETS_BUDGET_DURATION : value}
-                              onChange={(next) => onChange(next === NEVER_RESETS_BUDGET_DURATION ? null : next)}
+                              onChange={(next) =>
+                                onChange(next === NEVER_RESETS_BUDGET_DURATION ? null : next ?? undefined)
+                              }
                             />
                           )}
                         </FormField>