diff --git a/src/app/shared/stores/global-search/global-search.state.spec.ts b/src/app/shared/stores/global-search/global-search.state.spec.ts
index dd78a40d0..4efcf706d 100644
--- a/src/app/shared/stores/global-search/global-search.state.spec.ts
+++ b/src/app/shared/stores/global-search/global-search.state.spec.ts
@@ -264,4 +264,59 @@ describe('GlobalSearchState', () => {
       expect(params['cardSearchFilter[defaultKey][]']).toBe('default-value');
     });
   });
+
+  describe('updateResourcesState (CEDAR filter key collision)', () => {
+    const COLLIDING_API_FILTER: DiscoverableFilter = {
+      key: CEDAR_FILTER.key,
+      label: 'School Type (from API)',
+      operator: FilterOperatorOption.AnyOf,
+      resultCount: 5,
+    };
+
+    const MOCK_RESOURCES_WITH_COLLIDING_FILTER: ResourcesData = {
+      resources: [],
+      filters: [COLLIDING_API_FILTER],
+      count: 5,
+      self: '',
+      first: null,
+      next: null,
+      previous: null,
+    };
+
+    it('should preserve cedarPropertyIri when API returns a filter with the same key as an extra filter', () => {
+      const { store, mockGetResources } = setup();
+      mockGetResources.mockReturnValue(of(MOCK_RESOURCES_WITH_COLLIDING_FILTER));
+
+      store.dispatch(new SetExtraFilters([CEDAR_FILTER]));
+      store.dispatch(new FetchResources());
+
+      const filters = store.selectSnapshot(GlobalSearchSelectors.getFilters);
+      const filter = filters.find((f) => f.key === CEDAR_FILTER.key);
+      expect(filter?.cedarPropertyIri).toBe(CEDAR_FILTER.cedarPropertyIri);
+      expect(filter?.options).toEqual(CEDAR_FILTER.options);
+    });
+
+    it('should use cardSearchText even when the API returns a filter with the same key', () => {
+      const { store, mockGetResources } = setup();
+      mockGetResources.mockReturnValue(of(MOCK_RESOURCES_WITH_COLLIDING_FILTER));
+
+      store.dispatch(new SetExtraFilters([CEDAR_FILTER]));
+      store.dispatch(new FetchResources());
+      mockGetResources.mockClear();
+      mockGetResources.mockReturnValue(of(MOCK_RESOURCES_DATA));
+
+      store.dispatch(
+        new LoadFilterOptionsAndSetValues({
+          [CEDAR_FILTER.key]: [{ label: 'High School', value: 'High School', cardSearchResultCount: null }],
+        })
+      );
+      store.dispatch(new FetchResources());
+
+      const params = mockGetResources.mock.calls[0][0];
+      expect(params[`cardSearchText[osf:hasCedarRecord.cedar:${CEDAR_FILTER.cedarPropertyIri}][]`]).toEqual([
+        '"High School"',
+      ]);
+      expect(params[`cardSearchFilter[${CEDAR_FILTER.key}][]`]).toBeUndefined();
+    });
+  });
 });
diff --git a/src/app/shared/stores/global-search/global-search.state.ts b/src/app/shared/stores/global-search/global-search.state.ts
index bc7bb2710..f998b620b 100644
--- a/src/app/shared/stores/global-search/global-search.state.ts
+++ b/src/app/shared/stores/global-search/global-search.state.ts
@@ -63,7 +63,8 @@ export class GlobalSearchState {
     const state = ctx.getState();
     const filterKey = action.filterKey;
 
-    const filter = state.filters.find((f) => f.key === filterKey);
+    const filter =
+      state.filters.find((f) => f.key === filterKey) ?? state.extraFilters.find((f) => f.key === filterKey);
     if (filter?.cedarPropertyIri) {
       ctx.patchState({
         filters: state.filters.map((f) => (f.key === filterKey ? { ...f, isLoaded: true } : f)),
@@ -291,14 +292,27 @@ export class GlobalSearchState {
   private updateResourcesState(ctx: StateContext<GlobalSearchStateModel>, response: ResourcesData) {
     const { extraFilters } = ctx.getState();
     const apiFilterKeys = new Set(response.filters.map((f) => f.key));
-    const merged = [...response.filters, ...extraFilters.filter((f) => !apiFilterKeys.has(f.key))];
+
+    const extraByKey = new Map(extraFilters.map((ef) => [ef.key, ef]));
+
+    const merged = response.filters.map((apiFilter) => {
+      const cedarExtra = extraByKey.get(apiFilter.key);
+      if (!cedarExtra) return apiFilter;
+
+      return {
+        ...apiFilter,
+        cedarPropertyIri: cedarExtra.cedarPropertyIri,
+        ...(cedarExtra.options !== undefined && { options: cedarExtra.options }),
+      };
+    });
+    const extraFiltersNotInApi = extraFilters.filter((ef) => !apiFilterKeys.has(ef.key));
 
     ctx.patchState({
       resources: { data: response.resources, isLoading: false, error: null },
       filterOptionsCache: {},
       filterSearchCache: {},
       filterPaginationCache: {},
-      filters: merged,
+      filters: [...merged, ...extraFiltersNotInApi],
       resourcesCount: response.count,
       first: response.first,
       next: response.next,