diff --git a/go/pkg/basecamp/doc.go b/go/pkg/basecamp/doc.go
index 35219ea2..b191a9ba 100644
--- a/go/pkg/basecamp/doc.go
+++ b/go/pkg/basecamp/doc.go
@@ -88,20 +88,26 @@
 //
 // # Working with Todos
 //
+// Todo APIs take todolistID or todoID directly; projectID is not required.
+//
 // List todos in a todolist:
 //
-//	todos, err := account.Todos().List(ctx, projectID, todolistID, nil)
+//	todos, err := account.Todos().List(ctx, todolistID, nil)
+//
+// List completed todos in a todolist:
+//
+//	completed, err := account.Todos().List(ctx, todolistID, &basecamp.TodoListOptions{Status: "completed"})
 //
 // Create a todo:
 //
-//	todo, err := account.Todos().Create(ctx, projectID, todolistID, &basecamp.CreateTodoRequest{
+//	todo, err := account.Todos().Create(ctx, todolistID, &basecamp.CreateTodoRequest{
 //	    Content: "Ship the feature",
 //	    DueOn:   "2024-12-31",
 //	})
 //
 // Complete a todo:
 //
-//	err := account.Todos().Complete(ctx, projectID, todoID)
+//	err := account.Todos().Complete(ctx, todoID)
 //
 // # Searching
 //
@@ -176,6 +182,6 @@
 //	acme := client.ForAccount("12345")
 //	initech := client.ForAccount("67890")
 //
-//	go func() { acme.Todos().List(ctx, projectID, todolistID, nil) }()
+//	go func() { acme.Todos().List(ctx, todolistID, nil) }()
 //	go func() { initech.Projects().List(ctx, nil) }()
 package basecamp
diff --git a/go/pkg/basecamp/example_test.go b/go/pkg/basecamp/example_test.go
index e681e086..62c42394 100644
--- a/go/pkg/basecamp/example_test.go
+++ b/go/pkg/basecamp/example_test.go
@@ -134,7 +134,7 @@ func ExampleTodosService_List() {
 
 	todolistID := int64(789012)
 
-	// List all todos in a todolist
+	// List todos in a todolist
 	todosResult, err := client.ForAccount("12345").Todos().List(ctx, todolistID, nil)
 	if err != nil {
 		log.Fatal(err)
@@ -149,6 +149,26 @@ func ExampleTodosService_List() {
 	}
 }
 
+func ExampleTodosService_List_completed() {
+	cfg := basecamp.DefaultConfig()
+	token := &basecamp.StaticTokenProvider{Token: os.Getenv("BASECAMP_TOKEN")}
+	client := basecamp.NewClient(cfg, token)
+
+	ctx := context.Background()
+
+	todolistID := int64(789012)
+
+	// List completed todos in a todolist
+	todosResult, err := client.ForAccount("12345").Todos().List(ctx, todolistID, &basecamp.TodoListOptions{Status: "completed"})
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	for _, t := range todosResult.Todos {
+		fmt.Printf("[x] %s\n", t.Content)
+	}
+}
+
 func ExampleTodosService_Create() {
 	cfg := basecamp.DefaultConfig()
 	token := &basecamp.StaticTokenProvider{Token: os.Getenv("BASECAMP_TOKEN")}
diff --git a/go/pkg/basecamp/todos.go b/go/pkg/basecamp/todos.go
index 99bd0d5a..be4e3756 100644
--- a/go/pkg/basecamp/todos.go
+++ b/go/pkg/basecamp/todos.go
@@ -95,9 +95,10 @@ type Bucket struct {
 
 // TodoListOptions specifies options for listing todos.
 type TodoListOptions struct {
-	// Status filters by completion status.
-	// "completed" returns completed todos, "pending" returns pending todos.
-	// Empty returns all todos.
+	// Status filters todos by lifecycle or completion status.
+	// Lifecycle statuses: "active", "archived", "trashed".
+	// Backwards-compatible completion shorthands: "completed", "pending", "incomplete".
+	// Empty returns the API default (pending/incomplete todos).
 	Status string
 
 	// Limit is the maximum number of todos to return.
@@ -188,10 +189,26 @@ func (s *TodosService) List(ctx context.Context, todolistID int64, opts *TodoLis
 	ctx = s.client.parent.hooks.OnOperationStart(ctx, op)
 	defer func() { s.client.parent.hooks.OnOperationEnd(ctx, op, err, time.Since(start)) }()
 
-	// Build params for generated client
+	// Build params for generated client.
+	// The BC3 todos endpoint uses two different query shapes:
+	//   - status=active|archived|trashed for lifecycle state
+	//   - completed=true for completed todos
+	// Historically this wrapper exposed completion filtering via Status, so we
+	// keep mapping "completed"/"pending"/"incomplete" here for compatibility.
 	var params *generated.ListTodosParams
 	if opts != nil && opts.Status != "" {
-		params = &generated.ListTodosParams{Status: opts.Status}
+		built := &generated.ListTodosParams{}
+		switch opts.Status {
+		case "completed":
+			built.Completed = true
+		case "pending", "incomplete":
+			// Omit both params: the API returns pending/incomplete todos by default.
+		default:
+			built.Status = opts.Status
+		}
+		if built.Status != "" || built.Completed {
+			params = built
+		}
 	}
 
 	// Call generated client for first page (spec-conformant - no manual path construction)
diff --git a/go/pkg/basecamp/todos_test.go b/go/pkg/basecamp/todos_test.go
index b1a4f9ca..67fe0962 100644
--- a/go/pkg/basecamp/todos_test.go
+++ b/go/pkg/basecamp/todos_test.go
@@ -495,8 +495,12 @@ func TestTodoListOptions_StatusFilter(t *testing.T) {
 		name   string
 		status string
 	}{
+		{"active", "active"},
+		{"archived", "archived"},
+		{"trashed", "trashed"},
 		{"completed", "completed"},
 		{"pending", "pending"},
+		{"incomplete", "incomplete"},
 		{"empty", ""},
 	}
 
@@ -951,6 +955,127 @@ func testTodosServer(t *testing.T, handler http.HandlerFunc) *TodosService {
 	return account.Todos()
 }
 
+func TestTodosService_ListCompletedFilter(t *testing.T) {
+	fixture := loadTodosFixture(t, "list.json")
+	var gotStatus string
+	var gotCompleted string
+	var hasStatus bool
+	var hasCompleted bool
+
+	svc := testTodosServer(t, func(w http.ResponseWriter, r *http.Request) {
+		query := r.URL.Query()
+		hasStatus = query.Has("status")
+		hasCompleted = query.Has("completed")
+		gotStatus = query.Get("status")
+		gotCompleted = query.Get("completed")
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(200)
+		w.Write(fixture)
+	})
+
+	result, err := svc.List(context.Background(), 1069479519, &TodoListOptions{Status: "completed"})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(result.Todos) != 2 {
+		t.Fatalf("expected 2 todos, got %d", len(result.Todos))
+	}
+	if hasStatus {
+		t.Errorf("expected status query to be omitted, got %q", gotStatus)
+	}
+	if !hasCompleted || gotCompleted != "true" {
+		t.Errorf("expected completed=true, got present=%t value=%q", hasCompleted, gotCompleted)
+	}
+}
+
+func TestTodosService_ListPendingFilterOmitsQueryParams(t *testing.T) {
+	fixture := loadTodosFixture(t, "list.json")
+	var gotStatus string
+	var gotCompleted string
+	var hasStatus bool
+	var hasCompleted bool
+
+	svc := testTodosServer(t, func(w http.ResponseWriter, r *http.Request) {
+		query := r.URL.Query()
+		hasStatus = query.Has("status")
+		hasCompleted = query.Has("completed")
+		gotStatus = query.Get("status")
+		gotCompleted = query.Get("completed")
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(200)
+		w.Write(fixture)
+	})
+
+	_, err := svc.List(context.Background(), 1069479519, &TodoListOptions{Status: "pending"})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if hasStatus {
+		t.Errorf("expected status query to be omitted, got %q", gotStatus)
+	}
+	if hasCompleted {
+		t.Errorf("expected completed query to be omitted, got %q", gotCompleted)
+	}
+}
+
+func TestTodosService_ListIncompleteFilterOmitsQueryParams(t *testing.T) {
+	fixture := loadTodosFixture(t, "list.json")
+	var gotStatus string
+	var gotCompleted string
+	var hasStatus bool
+	var hasCompleted bool
+
+	svc := testTodosServer(t, func(w http.ResponseWriter, r *http.Request) {
+		query := r.URL.Query()
+		hasStatus = query.Has("status")
+		hasCompleted = query.Has("completed")
+		gotStatus = query.Get("status")
+		gotCompleted = query.Get("completed")
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(200)
+		w.Write(fixture)
+	})
+
+	_, err := svc.List(context.Background(), 1069479519, &TodoListOptions{Status: "incomplete"})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if hasStatus {
+		t.Errorf("expected status query to be omitted, got %q", gotStatus)
+	}
+	if hasCompleted {
+		t.Errorf("expected completed query to be omitted, got %q", gotCompleted)
+	}
+}
+
+func TestTodosService_ListLifecycleStatusFilter(t *testing.T) {
+	fixture := loadTodosFixture(t, "list.json")
+	var gotStatus string
+	var gotCompleted string
+	var hasCompleted bool
+
+	svc := testTodosServer(t, func(w http.ResponseWriter, r *http.Request) {
+		query := r.URL.Query()
+		gotStatus = query.Get("status")
+		hasCompleted = query.Has("completed")
+		gotCompleted = query.Get("completed")
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(200)
+		w.Write(fixture)
+	})
+
+	_, err := svc.List(context.Background(), 1069479519, &TodoListOptions{Status: "archived"})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if gotStatus != "archived" {
+		t.Errorf("expected status=archived, got %q", gotStatus)
+	}
+	if hasCompleted {
+		t.Errorf("expected completed query to be omitted, got %q", gotCompleted)
+	}
+}
+
 func TestTodosService_Update(t *testing.T) {
 	fixture := loadTodosFixture(t, "get.json")
 	var receivedBody map[string]any