diff --git a/prisma/migrations/20260825073402_add_asset_item_status_lost/migration.sql b/prisma/migrations/20260825073402_add_asset_item_status_lost/migration.sql
new file mode 100644
index 0000000..5dab1fe
--- /dev/null
+++ b/prisma/migrations/20260825073402_add_asset_item_status_lost/migration.sql
@@ -0,0 +1,2 @@
+-- Hand-written (same deviation as other 2026-08-2x migrations -- see CLAUDE.md).
+ALTER TYPE "AssetItemStatus" ADD VALUE 'lost';
diff --git a/prisma/schema.prisma b/prisma/schema.prisma
index e52e431..80a0d8f 100644
--- a/prisma/schema.prisma
+++ b/prisma/schema.prisma
@@ -84,14 +84,19 @@ model Employee {
   @@map("employees")
 }
 
-// Fixed, closed set of 4 values tied to the domain (see docs/
+// Fixed, closed set of values tied to the domain (see docs/
 // asset-license-management.md's "Data model (sơ bộ)" table) — native
-// Postgres enum, same rationale as RequestType above.
+// Postgres enum, same rationale as RequestType above. `lost` added
+// 2026-08-25 (ALTER TYPE ... ADD VALUE, not a table -- see the
+// 2026-08-24/25 discussion in CLAUDE.md on why this stays an enum: the
+// values are read directly by business logic, e.g. createAssignment()'s
+// `status !== "in_stock"` gate, not just display labels).
 enum AssetItemStatus {
   in_stock
   assigned
   repair
   retired
+  lost
 }
 
 // Hardware inventory — see docs/asset-license-management.md's "Data model
diff --git a/src/app/assets/page.tsx b/src/app/assets/page.tsx
index 19fd7bb..9fc4bb0 100644
--- a/src/app/assets/page.tsx
+++ b/src/app/assets/page.tsx
@@ -30,7 +30,7 @@ interface AssetItemRecord {
   model_id: string;
   purchase_date: string | null;
   warranty_end_date: string | null;
-  status: "in_stock" | "assigned" | "repair" | "retired";
+  status: "in_stock" | "assigned" | "repair" | "retired" | "lost";
   cost: number | null;
   cost_currency: string | null;
   purchase_order_id: string | null;
@@ -40,13 +40,24 @@ interface AssetItemRecord {
 
 // Shape returned by GET /api/asset-models — only the fields used to populate
 // the modelId <Select> here (see src/app/asset-models/page.tsx's
-// AssetModelRecord for the full shape).
+// AssetModelRecord for the full shape). category_id added 2026-08-25, used
+// to narrow the Model filter dropdown once a Category is picked -- with
+// 135 models after the 2026-08-24 real-data import, an unfiltered list is
+// unwieldy.
 interface AssetModelRecord {
   id: string;
+  category_id: string;
   manufacturer: string;
   name: string;
 }
 
+// Shape returned by GET /api/asset-categories — only id/name, used to
+// populate the Category filter <Select> here.
+interface AssetCategoryRecord {
+  id: string;
+  name: string;
+}
+
 // Shape returned by GET /api/purchase-orders — only the id, used to populate
 // the purchaseOrderId <Select> here. PurchaseOrder has no obviously
 // human-readable name field (see src/app/purchase-orders/page.tsx's
@@ -71,6 +82,7 @@ export default function AssetsPage() {
   } = useApiList<AssetItemRecord>("/api/assets");
 
   const { data: assetModels } = useApiList<AssetModelRecord>("/api/asset-models");
+  const { data: assetCategories } = useApiList<AssetCategoryRecord>("/api/asset-categories");
   const { data: purchaseOrders } = useApiList<PurchaseOrderRecord>("/api/purchase-orders");
 
   const [serialNumber, setSerialNumber] = useState("");
@@ -91,6 +103,7 @@ export default function AssetsPage() {
   // in memory" territory; no need for a server-side filtered endpoint).
   const [searchText, setSearchText] = useState("");
   const [filterStatus, setFilterStatus] = useState("all");
+  const [filterCategoryId, setFilterCategoryId] = useState("all");
   const [filterModelId, setFilterModelId] = useState("all");
 
   // modelId -> "Manufacturer Name" -- avoids showing the raw model_id UUID
@@ -103,18 +116,51 @@ export default function AssetsPage() {
     return map;
   }, [assetModels]);
 
+  const modelCategoryById = useMemo(() => {
+    const map = new Map<string, string>();
+    for (const m of assetModels) {
+      map.set(m.id, m.category_id);
+    }
+    return map;
+  }, [assetModels]);
+
+  // Model dropdown options narrow to the picked Category -- with 135
+  // models after the 2026-08-24 real-data import, showing all of them
+  // regardless of category is unwieldy.
+  const modelsForCategoryFilter = useMemo(() => {
+    if (filterCategoryId === "all") return assetModels;
+    return assetModels.filter((m) => m.category_id === filterCategoryId);
+  }, [assetModels, filterCategoryId]);
+
+  function handleFilterCategoryChange(categoryId: string) {
+    setFilterCategoryId(categoryId);
+    // A previously-picked Model may not belong to the newly-picked
+    // Category -- reset rather than silently keep filtering on a model
+    // that's no longer shown in the (now-narrowed) dropdown.
+    if (
+      filterModelId !== "all" &&
+      categoryId !== "all" &&
+      modelCategoryById.get(filterModelId) !== categoryId
+    ) {
+      setFilterModelId("all");
+    }
+  }
+
   const filteredAssetItems = useMemo(() => {
     const query = searchText.trim().toLowerCase();
     return assetItems.filter((item) => {
       if (filterStatus !== "all" && item.status !== filterStatus) return false;
       if (filterModelId !== "all" && item.model_id !== filterModelId) return false;
+      if (filterCategoryId !== "all" && modelCategoryById.get(item.model_id) !== filterCategoryId) {
+        return false;
+      }
       if (query) {
         const haystack = `${item.serial_number} ${item.asset_tag ?? ""}`.toLowerCase();
         if (!haystack.includes(query)) return false;
       }
       return true;
     });
-  }, [assetItems, searchText, filterStatus, filterModelId]);
+  }, [assetItems, searchText, filterStatus, filterModelId, filterCategoryId, modelCategoryById]);
 
   const [importStatus, setImportStatus] = useState<"idle" | "uploading" | "done" | "error">(
     "idle"
@@ -263,6 +309,24 @@ export default function AssetsPage() {
                 <SelectItem value="assigned">assigned</SelectItem>
                 <SelectItem value="repair">repair</SelectItem>
                 <SelectItem value="retired">retired</SelectItem>
+                <SelectItem value="lost">lost</SelectItem>
+              </SelectContent>
+            </Select>
+          </div>
+
+          <div className="flex flex-col gap-2">
+            <Label htmlFor="filterCategory">Category</Label>
+            <Select value={filterCategoryId} onValueChange={handleFilterCategoryChange}>
+              <SelectTrigger id="filterCategory" className="w-52">
+                <SelectValue />
+              </SelectTrigger>
+              <SelectContent>
+                <SelectItem value="all">All</SelectItem>
+                {assetCategories.map((assetCategory) => (
+                  <SelectItem key={assetCategory.id} value={assetCategory.id}>
+                    {assetCategory.name}
+                  </SelectItem>
+                ))}
               </SelectContent>
             </Select>
           </div>
@@ -275,7 +339,7 @@ export default function AssetsPage() {
               </SelectTrigger>
               <SelectContent>
                 <SelectItem value="all">All</SelectItem>
-                {assetModels.map((assetModel) => (
+                {modelsForCategoryFilter.map((assetModel) => (
                   <SelectItem key={assetModel.id} value={assetModel.id}>
                     {assetModel.manufacturer} {assetModel.name}
                   </SelectItem>
diff --git a/src/lib/assets.ts b/src/lib/assets.ts
index 92c500d..3e7cbe8 100644
--- a/src/lib/assets.ts
+++ b/src/lib/assets.ts
@@ -3,7 +3,7 @@ import { Prisma } from "@prisma/client";
 import { prisma } from "./prisma";
 import { splitCsvLine, splitCsvLines, normalizeHeader, csvField } from "./csv";
 
-export type AssetItemStatus = "in_stock" | "assigned" | "repair" | "retired";
+export type AssetItemStatus = "in_stock" | "assigned" | "repair" | "retired" | "lost";
 
 export interface AssetItemRecord {
   id: string;
@@ -455,6 +455,8 @@ const IMPORT_STATUS_MAP: Record<string, AssetItemStatus> = {
   "in repair": "repair",
   retired: "retired",
   disposed: "retired",
+  lost: "lost",
+  missing: "lost",
 };
 
 function statusFromImportText(text: string): AssetItemStatus | null {