diff --git a/toolchain/check/check.cpp b/toolchain/check/check.cpp
index 9fbe96cac4e0..3506cd3125fe 100644
--- a/toolchain/check/check.cpp
+++ b/toolchain/check/check.cpp
@@ -52,7 +52,7 @@ class SemIRLocationTranslator
 
       // If the parse node was invalid, recurse through import references when
       // possible.
-      if (auto import_ref = cursor_ir->insts().TryGetAs<SemIR::ImportRefUnused>(
+      if (auto import_ref = cursor_ir->insts().TryGetAs<SemIR::AnyImportRef>(
               cursor_inst_id)) {
         cursor_ir = cursor_ir->cross_ref_irs().Get(import_ref->ir_id);
         cursor_inst_id = import_ref->inst_id;
diff --git a/toolchain/check/context.cpp b/toolchain/check/context.cpp
index bbd0be38f41b..ffe83eddc1fb 100644
--- a/toolchain/check/context.cpp
+++ b/toolchain/check/context.cpp
@@ -221,46 +221,26 @@ auto Context::AddNameToLookup(SemIR::NameId name_id, SemIR::InstId target_id)
 
 auto Context::ResolveIfImportRefUnused(SemIR::InstId inst_id) -> void {
   auto inst = insts().Get(inst_id);
-  auto lazy_inst = inst.TryAs<SemIR::ImportRefUnused>();
-  if (!lazy_inst) {
+  auto unused_inst = inst.TryAs<SemIR::ImportRefUnused>();
+  if (!unused_inst) {
     return;
   }
-  const SemIR::File& import_ir = *cross_ref_irs().Get(lazy_inst->ir_id);
-  auto import_inst = import_ir.insts().Get(lazy_inst->inst_id);
+  const SemIR::File& import_ir = *cross_ref_irs().Get(unused_inst->ir_id);
+  auto import_inst = import_ir.insts().Get(unused_inst->inst_id);
   switch (import_inst.kind()) {
-    case SemIR::InstKind::FunctionDecl: {
-      // TODO: Fill this in better.
-      auto function_id =
-          functions().Add({.name_id = SemIR::NameId::Invalid,
-                           .enclosing_scope_id = SemIR::NameScopeId::Invalid,
-                           .decl_id = inst_id,
-                           .implicit_param_refs_id = SemIR::InstBlockId::Empty,
-                           .param_refs_id = SemIR::InstBlockId::Empty,
-                           .return_type_id = SemIR::TypeId::Invalid,
-                           .return_slot_id = SemIR::InstId::Invalid});
-      ReplaceInstBeforeConstantUse(
-          inst_id,
-          // TODO: For diagnostic purposes, we should provide some form of
-          // location for the function.
-          {Parse::NodeId::Invalid,
-           SemIR::FunctionDecl{GetBuiltinType(SemIR::BuiltinKind::FunctionType),
-                               function_id}});
-      constant_values().Set(inst_id,
-                            SemIR::ConstantId::ForTemplateConstant(inst_id));
-      break;
-    }
-
     default:
       // TODO: We need more type support. For now we inject an arbitrary
       // invalid node that's unrelated to the underlying value. The TODO
       // diagnostic is used since this section shouldn't typically be able to
       // error.
       TODO(Parse::NodeId::Invalid,
-           (llvm::Twine("TODO: support ") + import_inst.kind().name()).str());
+           (llvm::Twine("TODO: ResolveIfImportRefUnused for ") +
+            import_inst.kind().name())
+               .str());
       ReplaceInstBeforeConstantUse(
-          inst_id, {Parse::NodeId::Invalid,
-                    SemIR::VarStorage{SemIR::TypeId::Error,
-                                      SemIR::NameId::PackageNamespace}});
+          inst_id,
+          {SemIR::ImportRefUsed{SemIR::TypeId::Error, unused_inst->ir_id,
+                                unused_inst->inst_id}});
       break;
   }
 }
@@ -970,6 +950,7 @@ class TypeCompleter {
       case SemIR::InterfaceDecl::Kind:
       case SemIR::IntLiteral::Kind:
       case SemIR::ImportRefUnused::Kind:
+      case SemIR::ImportRefUsed::Kind:
       case SemIR::NameRef::Kind:
       case SemIR::Namespace::Kind:
       case SemIR::Param::Kind:
diff --git a/toolchain/check/eval.cpp b/toolchain/check/eval.cpp
index 42b296aaf654..34ef76c649fe 100644
--- a/toolchain/check/eval.cpp
+++ b/toolchain/check/eval.cpp
@@ -477,6 +477,7 @@ auto TryEvalInst(Context& context, SemIR::InstId inst_id, SemIR::Inst inst)
     case SemIR::ClassDecl::Kind:
     case SemIR::Import::Kind:
     case SemIR::ImportRefUnused::Kind:
+    case SemIR::ImportRefUsed::Kind:
     case SemIR::InterfaceDecl::Kind:
     case SemIR::Param::Kind:
     case SemIR::ReturnExpr::Kind:
diff --git a/toolchain/check/import.cpp b/toolchain/check/import.cpp
index 99a7da9f4d7b..2ccebf195dc7 100644
--- a/toolchain/check/import.cpp
+++ b/toolchain/check/import.cpp
@@ -103,8 +103,8 @@ static auto CopySingleNameScopeFromImportIR(
   }
 
   // Produce the namespace for the entry.
-  auto ref_id = context.AddInst(
-      SemIR::ImportRefUnused{.ir_id = ir_id, .inst_id = import_inst_id});
+  auto ref_id = context.AddInst(SemIR::ImportRefUsed{
+      .type_id = namespace_type_id, .ir_id = ir_id, .inst_id = import_inst_id});
   auto namespace_inst =
       SemIR::Namespace{namespace_type_id, SemIR::NameScopeId::Invalid, ref_id};
   // Use the invalid node because there's no node to associate with.
diff --git a/toolchain/check/testdata/namespace/add_to_import.carbon b/toolchain/check/testdata/namespace/add_to_import.carbon
index b5aac87543fd..f600f14fc088 100644
--- a/toolchain/check/testdata/namespace/add_to_import.carbon
+++ b/toolchain/check/testdata/namespace/add_to_import.carbon
@@ -33,7 +33,7 @@ var a: i32 = NS.A();
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace {.NS = %.2, .a = %a} [template]
-// CHECK:STDOUT:   %import_ref = import_ref ir1, inst+1, unused
+// CHECK:STDOUT:   %import_ref: <namespace> = import_ref ir1, inst+1, used
 // CHECK:STDOUT:   %.2: <namespace> = namespace {.A = %A}, %import_ref [template]
 // CHECK:STDOUT:   %A: <function> = fn_decl @A [template]
 // CHECK:STDOUT:   %a.var: ref i32 = var a
diff --git a/toolchain/check/testdata/namespace/fail_conflict_after_merge.carbon b/toolchain/check/testdata/namespace/fail_conflict_after_merge.carbon
index f2d385f36d39..ece70aee5e18 100644
--- a/toolchain/check/testdata/namespace/fail_conflict_after_merge.carbon
+++ b/toolchain/check/testdata/namespace/fail_conflict_after_merge.carbon
@@ -51,7 +51,7 @@ fn NS();
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace {.NS = %.loc8_13.1} [template]
-// CHECK:STDOUT:   %import_ref = import_ref ir1, inst+1, unused
+// CHECK:STDOUT:   %import_ref: <namespace> = import_ref ir1, inst+1, used
 // CHECK:STDOUT:   %.loc8_13.1: <namespace> = namespace {}, %import_ref [template]
 // CHECK:STDOUT:   %.loc8_13.2: <namespace> = namespace {} [template]
 // CHECK:STDOUT:   %.loc16: <function> = fn_decl @.1 [template]
diff --git a/toolchain/check/testdata/namespace/fail_conflict_imported_namespace_first.carbon b/toolchain/check/testdata/namespace/fail_conflict_imported_namespace_first.carbon
index ea49e131f5e8..e9eece50164a 100644
--- a/toolchain/check/testdata/namespace/fail_conflict_imported_namespace_first.carbon
+++ b/toolchain/check/testdata/namespace/fail_conflict_imported_namespace_first.carbon
@@ -37,7 +37,7 @@ fn NS.Foo();
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace {.NS = %.2} [template]
-// CHECK:STDOUT:   %import_ref = import_ref ir1, inst+1, unused
+// CHECK:STDOUT:   %import_ref: <namespace> = import_ref ir1, inst+1, used
 // CHECK:STDOUT:   %.2: <namespace> = namespace {.Foo = %Foo}, %import_ref [template]
 // CHECK:STDOUT:   %.loc12: <function> = fn_decl @.1 [template]
 // CHECK:STDOUT:   %Foo: <function> = fn_decl @Foo [template]
diff --git a/toolchain/check/testdata/namespace/fail_conflict_imported_namespace_second.carbon b/toolchain/check/testdata/namespace/fail_conflict_imported_namespace_second.carbon
index db1c7478bbdd..b889adcfcc37 100644
--- a/toolchain/check/testdata/namespace/fail_conflict_imported_namespace_second.carbon
+++ b/toolchain/check/testdata/namespace/fail_conflict_imported_namespace_second.carbon
@@ -3,6 +3,7 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // AUTOUPDATE
+// CHECK:STDERR: conflict.carbon: ERROR: Semantics TODO: `TODO: ResolveIfImportRefUnused for FunctionDecl`.
 
 // --- fn.carbon
 
@@ -16,10 +17,12 @@ package Example api;
 
 import library "fn";
 
-// CHECK:STDERR: conflict.carbon:[[@LINE+4]]:1: ERROR: Duplicate name being declared in the same scope.
+// CHECK:STDERR: conflict.carbon:[[@LINE+6]]:1: ERROR: Duplicate name being declared in the same scope.
 // CHECK:STDERR: namespace NS;
 // CHECK:STDERR: ^~~~~~~~~~~~~
-// CHECK:STDERR: conflict.carbon: Name is previously declared here.
+// CHECK:STDERR: fn.carbon:4:1: Name is previously declared here.
+// CHECK:STDERR: fn NS();
+// CHECK:STDERR: ^~~~~~~~
 namespace NS;
 
 // CHECK:STDERR: conflict.carbon:[[@LINE+6]]:7: ERROR: Name qualifiers are only allowed for entities that provide a scope.
@@ -42,13 +45,11 @@ fn NS.Foo();
 // CHECK:STDOUT: --- conflict.carbon
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
-// CHECK:STDOUT:   package: <namespace> = namespace {.NS = %.2} [template]
-// CHECK:STDOUT:   %.2: <function> = fn_decl @.1 [template]
-// CHECK:STDOUT:   %.loc10: <namespace> = namespace {} [template]
-// CHECK:STDOUT:   %.loc18: <function> = fn_decl @.2 [template]
+// CHECK:STDOUT:   package: <namespace> = namespace {.NS = %import_ref} [template]
+// CHECK:STDOUT:   %import_ref: <error> = import_ref ir1, inst+1, used
+// CHECK:STDOUT:   %.loc12: <namespace> = namespace {} [template]
+// CHECK:STDOUT:   %.loc20: <function> = fn_decl @.1 [template]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @.1();
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @.2();
-// CHECK:STDOUT:
diff --git a/toolchain/check/testdata/namespace/fail_conflict_in_imports_namespace_first.carbon b/toolchain/check/testdata/namespace/fail_conflict_in_imports_namespace_first.carbon
index 13e0e3d1333c..705098a02c4c 100644
--- a/toolchain/check/testdata/namespace/fail_conflict_in_imports_namespace_first.carbon
+++ b/toolchain/check/testdata/namespace/fail_conflict_in_imports_namespace_first.carbon
@@ -61,7 +61,7 @@ fn NS.Bar() {}
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace {.NS = %.2} [template]
-// CHECK:STDOUT:   %import_ref.1 = import_ref ir1, inst+1, unused
+// CHECK:STDOUT:   %import_ref.1: <namespace> = import_ref ir1, inst+1, used
 // CHECK:STDOUT:   %.2: <namespace> = namespace {.Foo = %import_ref.2, .Bar = %Bar}, %import_ref.1 [template]
 // CHECK:STDOUT:   %import_ref.2 = import_ref ir1, inst+2, unused
 // CHECK:STDOUT:   %import_ref.3 = import_ref ir2, inst+1, unused
diff --git a/toolchain/check/testdata/namespace/fail_conflict_in_imports_namespace_second.carbon b/toolchain/check/testdata/namespace/fail_conflict_in_imports_namespace_second.carbon
index 4dc80b3b5a56..c068f40e382f 100644
--- a/toolchain/check/testdata/namespace/fail_conflict_in_imports_namespace_second.carbon
+++ b/toolchain/check/testdata/namespace/fail_conflict_in_imports_namespace_second.carbon
@@ -62,7 +62,7 @@ fn NS.Bar() {}
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace {.NS = %.2} [template]
 // CHECK:STDOUT:   %import_ref.1 = import_ref ir1, inst+1, unused
-// CHECK:STDOUT:   %import_ref.2 = import_ref ir2, inst+1, unused
+// CHECK:STDOUT:   %import_ref.2: <namespace> = import_ref ir2, inst+1, used
 // CHECK:STDOUT:   %.2: <namespace> = namespace {.Foo = %import_ref.3, .Bar = %Bar}, %import_ref.2 [template]
 // CHECK:STDOUT:   %import_ref.3 = import_ref ir2, inst+2, unused
 // CHECK:STDOUT:   %Bar: <function> = fn_decl @Bar [template]
diff --git a/toolchain/check/testdata/namespace/imported.carbon b/toolchain/check/testdata/namespace/fail_todo_imported.carbon
similarity index 73%
rename from toolchain/check/testdata/namespace/imported.carbon
rename to toolchain/check/testdata/namespace/fail_todo_imported.carbon
index 2dcee03e4710..4bbb9246e60e 100644
--- a/toolchain/check/testdata/namespace/imported.carbon
+++ b/toolchain/check/testdata/namespace/fail_todo_imported.carbon
@@ -3,6 +3,8 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // AUTOUPDATE
+// CHECK:STDERR: implicit.impl.carbon: ERROR: Semantics TODO: `TODO: ResolveIfImportRefUnused for FunctionDecl`.
+// CHECK:STDERR: implicit.impl.carbon: ERROR: Semantics TODO: `TODO: ResolveIfImportRefUnused for FunctionDecl`.
 
 // --- implicit.carbon
 
@@ -46,38 +48,35 @@ var package_b: () = package.NS.ChildNS.B();
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace {.NS = %.2, .a = %a, .b = %b, .package_a = %package_a, .package_b = %package_b} [template]
-// CHECK:STDOUT:   %import_ref.1 = import_ref ir1, inst+1, unused
-// CHECK:STDOUT:   %.2: <namespace> = namespace {.ChildNS = %.3, .A = %.4}, %import_ref.1 [template]
-// CHECK:STDOUT:   %import_ref.2 = import_ref ir1, inst+2, unused
-// CHECK:STDOUT:   %.3: <namespace> = namespace {.B = %.5}, %import_ref.2 [template]
-// CHECK:STDOUT:   %.4: <function> = fn_decl @.1 [template]
-// CHECK:STDOUT:   %.5: <function> = fn_decl @.2 [template]
+// CHECK:STDOUT:   %import_ref.1: <namespace> = import_ref ir1, inst+1, used
+// CHECK:STDOUT:   %.2: <namespace> = namespace {.ChildNS = %.3, .A = %import_ref.3}, %import_ref.1 [template]
+// CHECK:STDOUT:   %import_ref.2: <namespace> = import_ref ir1, inst+2, used
+// CHECK:STDOUT:   %.3: <namespace> = namespace {.B = %import_ref.4}, %import_ref.2 [template]
+// CHECK:STDOUT:   %import_ref.3: <error> = import_ref ir1, inst+3, used
+// CHECK:STDOUT:   %import_ref.4: <error> = import_ref ir1, inst+4, used
 // CHECK:STDOUT:   %.loc4_9.1: () = tuple_literal ()
 // CHECK:STDOUT:   %.loc4_9.2: type = converted %.loc4_9.1, constants.%.1 [template = constants.%.1]
 // CHECK:STDOUT:   %a.var: ref () = var a
 // CHECK:STDOUT:   %a: ref () = bind_name a, %a.var
 // CHECK:STDOUT:   %NS.ref.loc4: <namespace> = name_ref NS, %.2 [template = %.2]
-// CHECK:STDOUT:   %A.ref.loc4: <function> = name_ref A, %.4 [template = %.4]
-// CHECK:STDOUT:   %.loc4_17: init () = call %A.ref.loc4()
-// CHECK:STDOUT:   assign %a.var, %.loc4_17
+// CHECK:STDOUT:   %A.ref.loc4: <error> = name_ref A, %import_ref.3
+// CHECK:STDOUT:   assign %a.var, <error>
 // CHECK:STDOUT:   %.loc5_9.1: () = tuple_literal ()
 // CHECK:STDOUT:   %.loc5_9.2: type = converted %.loc5_9.1, constants.%.1 [template = constants.%.1]
 // CHECK:STDOUT:   %b.var: ref () = var b
 // CHECK:STDOUT:   %b: ref () = bind_name b, %b.var
 // CHECK:STDOUT:   %NS.ref.loc5: <namespace> = name_ref NS, %.2 [template = %.2]
 // CHECK:STDOUT:   %ChildNS.ref.loc5: <namespace> = name_ref ChildNS, %.3 [template = %.3]
-// CHECK:STDOUT:   %B.ref.loc5: <function> = name_ref B, %.5 [template = %.5]
-// CHECK:STDOUT:   %.loc5_25: init () = call %B.ref.loc5()
-// CHECK:STDOUT:   assign %b.var, %.loc5_25
+// CHECK:STDOUT:   %B.ref.loc5: <error> = name_ref B, %import_ref.4
+// CHECK:STDOUT:   assign %b.var, <error>
 // CHECK:STDOUT:   %.loc7_17.1: () = tuple_literal ()
 // CHECK:STDOUT:   %.loc7_17.2: type = converted %.loc7_17.1, constants.%.1 [template = constants.%.1]
 // CHECK:STDOUT:   %package_a.var: ref () = var package_a
 // CHECK:STDOUT:   %package_a: ref () = bind_name package_a, %package_a.var
 // CHECK:STDOUT:   %package.ref.loc7: <namespace> = name_ref package, package [template = package]
 // CHECK:STDOUT:   %NS.ref.loc7: <namespace> = name_ref NS, %.2 [template = %.2]
-// CHECK:STDOUT:   %A.ref.loc7: <function> = name_ref A, %.4 [template = %.4]
-// CHECK:STDOUT:   %.loc7_33: init () = call %A.ref.loc7()
-// CHECK:STDOUT:   assign %package_a.var, %.loc7_33
+// CHECK:STDOUT:   %A.ref.loc7: <error> = name_ref A, %import_ref.3
+// CHECK:STDOUT:   assign %package_a.var, <error>
 // CHECK:STDOUT:   %.loc8_17.1: () = tuple_literal ()
 // CHECK:STDOUT:   %.loc8_17.2: type = converted %.loc8_17.1, constants.%.1 [template = constants.%.1]
 // CHECK:STDOUT:   %package_b.var: ref () = var package_b
@@ -85,12 +84,7 @@ var package_b: () = package.NS.ChildNS.B();
 // CHECK:STDOUT:   %package.ref.loc8: <namespace> = name_ref package, package [template = package]
 // CHECK:STDOUT:   %NS.ref.loc8: <namespace> = name_ref NS, %.2 [template = %.2]
 // CHECK:STDOUT:   %ChildNS.ref.loc8: <namespace> = name_ref ChildNS, %.3 [template = %.3]
-// CHECK:STDOUT:   %B.ref.loc8: <function> = name_ref B, %.5 [template = %.5]
-// CHECK:STDOUT:   %.loc8_41: init () = call %B.ref.loc8()
-// CHECK:STDOUT:   assign %package_b.var, %.loc8_41
+// CHECK:STDOUT:   %B.ref.loc8: <error> = name_ref B, %import_ref.4
+// CHECK:STDOUT:   assign %package_b.var, <error>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @.1();
-// CHECK:STDOUT:
-// CHECK:STDOUT: fn @.2();
-// CHECK:STDOUT:
diff --git a/toolchain/check/testdata/namespace/imported_indirect.carbon b/toolchain/check/testdata/namespace/fail_todo_imported_indirect.carbon
similarity index 74%
rename from toolchain/check/testdata/namespace/imported_indirect.carbon
rename to toolchain/check/testdata/namespace/fail_todo_imported_indirect.carbon
index dc9f7e3b85d8..a19132765ec6 100644
--- a/toolchain/check/testdata/namespace/imported_indirect.carbon
+++ b/toolchain/check/testdata/namespace/fail_todo_imported_indirect.carbon
@@ -3,6 +3,7 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // AUTOUPDATE
+// CHECK:STDERR: e.carbon: ERROR: Semantics TODO: `TODO: ResolveIfImportRefUnused for FunctionDecl`.
 
 // --- a.carbon
 
@@ -49,7 +50,7 @@ var e: () = A.B.C.D();
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace {.A = %.2} [template]
-// CHECK:STDOUT:   %import_ref = import_ref ir1, inst+1, unused
+// CHECK:STDOUT:   %import_ref: <namespace> = import_ref ir1, inst+1, used
 // CHECK:STDOUT:   %.2: <namespace> = namespace {.B = %.loc5}, %import_ref [template]
 // CHECK:STDOUT:   %.loc5: <namespace> = namespace {} [template]
 // CHECK:STDOUT: }
@@ -58,9 +59,9 @@ var e: () = A.B.C.D();
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace {.A = %.2} [template]
-// CHECK:STDOUT:   %import_ref.1 = import_ref ir1, inst+2, unused
+// CHECK:STDOUT:   %import_ref.1: <namespace> = import_ref ir1, inst+2, used
 // CHECK:STDOUT:   %.2: <namespace> = namespace {.B = %.3}, %import_ref.1 [template]
-// CHECK:STDOUT:   %import_ref.2 = import_ref ir1, inst+3, unused
+// CHECK:STDOUT:   %import_ref.2: <namespace> = import_ref ir1, inst+3, used
 // CHECK:STDOUT:   %.3: <namespace> = namespace {.C = %.loc5}, %import_ref.2 [template]
 // CHECK:STDOUT:   %.loc5: <namespace> = namespace {} [template]
 // CHECK:STDOUT: }
@@ -69,11 +70,11 @@ var e: () = A.B.C.D();
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace {.A = %.2} [template]
-// CHECK:STDOUT:   %import_ref.1 = import_ref ir1, inst+2, unused
+// CHECK:STDOUT:   %import_ref.1: <namespace> = import_ref ir1, inst+2, used
 // CHECK:STDOUT:   %.2: <namespace> = namespace {.B = %.3}, %import_ref.1 [template]
-// CHECK:STDOUT:   %import_ref.2 = import_ref ir1, inst+4, unused
+// CHECK:STDOUT:   %import_ref.2: <namespace> = import_ref ir1, inst+4, used
 // CHECK:STDOUT:   %.3: <namespace> = namespace {.C = %.4}, %import_ref.2 [template]
-// CHECK:STDOUT:   %import_ref.3 = import_ref ir1, inst+5, unused
+// CHECK:STDOUT:   %import_ref.3: <namespace> = import_ref ir1, inst+5, used
 // CHECK:STDOUT:   %.4: <namespace> = namespace {.D = %D}, %import_ref.3 [template]
 // CHECK:STDOUT:   %D: <function> = fn_decl @D [template]
 // CHECK:STDOUT: }
@@ -91,13 +92,13 @@ var e: () = A.B.C.D();
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace {.A = %.2, .e = %e} [template]
-// CHECK:STDOUT:   %import_ref.1 = import_ref ir1, inst+2, unused
+// CHECK:STDOUT:   %import_ref.1: <namespace> = import_ref ir1, inst+2, used
 // CHECK:STDOUT:   %.2: <namespace> = namespace {.B = %.3}, %import_ref.1 [template]
-// CHECK:STDOUT:   %import_ref.2 = import_ref ir1, inst+4, unused
+// CHECK:STDOUT:   %import_ref.2: <namespace> = import_ref ir1, inst+4, used
 // CHECK:STDOUT:   %.3: <namespace> = namespace {.C = %.4}, %import_ref.2 [template]
-// CHECK:STDOUT:   %import_ref.3 = import_ref ir1, inst+6, unused
-// CHECK:STDOUT:   %.4: <namespace> = namespace {.D = %.5}, %import_ref.3 [template]
-// CHECK:STDOUT:   %.5: <function> = fn_decl @.1 [template]
+// CHECK:STDOUT:   %import_ref.3: <namespace> = import_ref ir1, inst+6, used
+// CHECK:STDOUT:   %.4: <namespace> = namespace {.D = %import_ref.4}, %import_ref.3 [template]
+// CHECK:STDOUT:   %import_ref.4: <error> = import_ref ir1, inst+7, used
 // CHECK:STDOUT:   %.loc5_9.1: () = tuple_literal ()
 // CHECK:STDOUT:   %.loc5_9.2: type = converted %.loc5_9.1, constants.%.1 [template = constants.%.1]
 // CHECK:STDOUT:   %e.var: ref () = var e
@@ -105,10 +106,7 @@ var e: () = A.B.C.D();
 // CHECK:STDOUT:   %A.ref: <namespace> = name_ref A, %.2 [template = %.2]
 // CHECK:STDOUT:   %B.ref: <namespace> = name_ref B, %.3 [template = %.3]
 // CHECK:STDOUT:   %C.ref: <namespace> = name_ref C, %.4 [template = %.4]
-// CHECK:STDOUT:   %D.ref: <function> = name_ref D, %.5 [template = %.5]
-// CHECK:STDOUT:   %.loc5_20: init () = call %D.ref()
-// CHECK:STDOUT:   assign %e.var, %.loc5_20
+// CHECK:STDOUT:   %D.ref: <error> = name_ref D, %import_ref.4
+// CHECK:STDOUT:   assign %e.var, <error>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @.1();
-// CHECK:STDOUT:
diff --git a/toolchain/check/testdata/namespace/merging.carbon b/toolchain/check/testdata/namespace/fail_todo_merging.carbon
similarity index 75%
rename from toolchain/check/testdata/namespace/merging.carbon
rename to toolchain/check/testdata/namespace/fail_todo_merging.carbon
index 97178c48ff48..ac3b271a3fdb 100644
--- a/toolchain/check/testdata/namespace/merging.carbon
+++ b/toolchain/check/testdata/namespace/fail_todo_merging.carbon
@@ -3,6 +3,9 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // AUTOUPDATE
+// CHECK:STDERR: c.carbon: ERROR: Semantics TODO: `TODO: ResolveIfImportRefUnused for FunctionDecl`.
+// CHECK:STDERR: c.carbon: ERROR: Semantics TODO: `TODO: ResolveIfImportRefUnused for FunctionDecl`.
+// CHECK:STDERR: c.carbon: ERROR: Semantics TODO: `TODO: ResolveIfImportRefUnused for FunctionDecl`.
 
 // --- a.carbon
 
@@ -83,11 +86,11 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace {.NS = %.loc7_13.1, .Run = %Run} [template]
-// CHECK:STDOUT:   %import_ref = import_ref ir1, inst+1, unused
-// CHECK:STDOUT:   %.loc7_13.1: <namespace> = namespace {.A = %.2, .B1 = %.3, .B2 = %.4, .C = %C}, %import_ref [template]
-// CHECK:STDOUT:   %.2: <function> = fn_decl @.1 [template]
-// CHECK:STDOUT:   %.3: <function> = fn_decl @.2 [template]
-// CHECK:STDOUT:   %.4: <function> = fn_decl @.3 [template]
+// CHECK:STDOUT:   %import_ref.1: <namespace> = import_ref ir1, inst+1, used
+// CHECK:STDOUT:   %.loc7_13.1: <namespace> = namespace {.A = %import_ref.2, .B1 = %import_ref.3, .B2 = %import_ref.4, .C = %C}, %import_ref.1 [template]
+// CHECK:STDOUT:   %import_ref.2: <error> = import_ref ir1, inst+2, used
+// CHECK:STDOUT:   %import_ref.3: <error> = import_ref ir2, inst+2, used
+// CHECK:STDOUT:   %import_ref.4: <error> = import_ref ir2, inst+5, used
 // CHECK:STDOUT:   %.loc7_13.2: <namespace> = namespace {} [template]
 // CHECK:STDOUT:   %C: <function> = fn_decl @C [template]
 // CHECK:STDOUT:   %Run: <function> = fn_decl @Run [template]
@@ -101,23 +104,14 @@ fn Run() {
 // CHECK:STDOUT: fn @Run() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %NS.ref.loc12: <namespace> = name_ref NS, file.%.loc7_13.1 [template = file.%.loc7_13.1]
-// CHECK:STDOUT:   %A.ref: <function> = name_ref A, file.%.2 [template = file.%.2]
-// CHECK:STDOUT:   %.loc12: init () = call %A.ref()
+// CHECK:STDOUT:   %A.ref: <error> = name_ref A, file.%import_ref.2
 // CHECK:STDOUT:   %NS.ref.loc13: <namespace> = name_ref NS, file.%.loc7_13.1 [template = file.%.loc7_13.1]
-// CHECK:STDOUT:   %B1.ref: <function> = name_ref B1, file.%.3 [template = file.%.3]
-// CHECK:STDOUT:   %.loc13: init () = call %B1.ref()
+// CHECK:STDOUT:   %B1.ref: <error> = name_ref B1, file.%import_ref.3
 // CHECK:STDOUT:   %NS.ref.loc14: <namespace> = name_ref NS, file.%.loc7_13.1 [template = file.%.loc7_13.1]
-// CHECK:STDOUT:   %B2.ref: <function> = name_ref B2, file.%.4 [template = file.%.4]
-// CHECK:STDOUT:   %.loc14: init () = call %B2.ref()
+// CHECK:STDOUT:   %B2.ref: <error> = name_ref B2, file.%import_ref.4
 // CHECK:STDOUT:   %NS.ref.loc15: <namespace> = name_ref NS, file.%.loc7_13.1 [template = file.%.loc7_13.1]
 // CHECK:STDOUT:   %C.ref: <function> = name_ref C, file.%C [template = file.%C]
 // CHECK:STDOUT:   %.loc15: init () = call %C.ref()
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @.1();
-// CHECK:STDOUT:
-// CHECK:STDOUT: fn @.2();
-// CHECK:STDOUT:
-// CHECK:STDOUT: fn @.3();
-// CHECK:STDOUT:
diff --git a/toolchain/check/testdata/packages/loaded_global.carbon b/toolchain/check/testdata/packages/fail_todo_loaded_global.carbon
similarity index 71%
rename from toolchain/check/testdata/packages/loaded_global.carbon
rename to toolchain/check/testdata/packages/fail_todo_loaded_global.carbon
index 278bda7407d2..bf638c0ea3a3 100644
--- a/toolchain/check/testdata/packages/loaded_global.carbon
+++ b/toolchain/check/testdata/packages/fail_todo_loaded_global.carbon
@@ -3,6 +3,8 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // AUTOUPDATE
+// CHECK:STDERR: implicit.impl.carbon: ERROR: Semantics TODO: `TODO: ResolveIfImportRefUnused for FunctionDecl`.
+// CHECK:STDERR: same_package_importer.carbon: ERROR: Semantics TODO: `TODO: ResolveIfImportRefUnused for FunctionDecl`.
 
 // --- implicit.carbon
 
@@ -50,27 +52,23 @@ var package_b: () = package.B();
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
-// CHECK:STDOUT:   package: <namespace> = namespace {.A = %.2, .a = %a, .package_a = %package_a} [template]
-// CHECK:STDOUT:   %.2: <function> = fn_decl @.1 [template]
+// CHECK:STDOUT:   package: <namespace> = namespace {.A = %import_ref, .a = %a, .package_a = %package_a} [template]
+// CHECK:STDOUT:   %import_ref: <error> = import_ref ir1, inst+1, used
 // CHECK:STDOUT:   %.loc4_9.1: () = tuple_literal ()
 // CHECK:STDOUT:   %.loc4_9.2: type = converted %.loc4_9.1, constants.%.1 [template = constants.%.1]
 // CHECK:STDOUT:   %a.var: ref () = var a
 // CHECK:STDOUT:   %a: ref () = bind_name a, %a.var
-// CHECK:STDOUT:   %A.ref.loc4: <function> = name_ref A, %.2 [template = %.2]
-// CHECK:STDOUT:   %.loc4_14: init () = call %A.ref.loc4()
-// CHECK:STDOUT:   assign %a.var, %.loc4_14
+// CHECK:STDOUT:   %A.ref.loc4: <error> = name_ref A, %import_ref
+// CHECK:STDOUT:   assign %a.var, <error>
 // CHECK:STDOUT:   %.loc6_17.1: () = tuple_literal ()
 // CHECK:STDOUT:   %.loc6_17.2: type = converted %.loc6_17.1, constants.%.1 [template = constants.%.1]
 // CHECK:STDOUT:   %package_a.var: ref () = var package_a
 // CHECK:STDOUT:   %package_a: ref () = bind_name package_a, %package_a.var
 // CHECK:STDOUT:   %package.ref: <namespace> = name_ref package, package [template = package]
-// CHECK:STDOUT:   %A.ref.loc6: <function> = name_ref A, %.2 [template = %.2]
-// CHECK:STDOUT:   %.loc6_30: init () = call %A.ref.loc6()
-// CHECK:STDOUT:   assign %package_a.var, %.loc6_30
+// CHECK:STDOUT:   %A.ref.loc6: <error> = name_ref A, %import_ref
+// CHECK:STDOUT:   assign %package_a.var, <error>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @.1();
-// CHECK:STDOUT:
 // CHECK:STDOUT: --- same_package.carbon
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
@@ -87,24 +85,20 @@ var package_b: () = package.B();
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
-// CHECK:STDOUT:   package: <namespace> = namespace {.B = %.2, .b = %b, .package_b = %package_b} [template]
-// CHECK:STDOUT:   %.2: <function> = fn_decl @.1 [template]
+// CHECK:STDOUT:   package: <namespace> = namespace {.B = %import_ref, .b = %b, .package_b = %package_b} [template]
+// CHECK:STDOUT:   %import_ref: <error> = import_ref ir1, inst+1, used
 // CHECK:STDOUT:   %.loc6_9.1: () = tuple_literal ()
 // CHECK:STDOUT:   %.loc6_9.2: type = converted %.loc6_9.1, constants.%.1 [template = constants.%.1]
 // CHECK:STDOUT:   %b.var: ref () = var b
 // CHECK:STDOUT:   %b: ref () = bind_name b, %b.var
-// CHECK:STDOUT:   %B.ref.loc6: <function> = name_ref B, %.2 [template = %.2]
-// CHECK:STDOUT:   %.loc6_14: init () = call %B.ref.loc6()
-// CHECK:STDOUT:   assign %b.var, %.loc6_14
+// CHECK:STDOUT:   %B.ref.loc6: <error> = name_ref B, %import_ref
+// CHECK:STDOUT:   assign %b.var, <error>
 // CHECK:STDOUT:   %.loc8_17.1: () = tuple_literal ()
 // CHECK:STDOUT:   %.loc8_17.2: type = converted %.loc8_17.1, constants.%.1 [template = constants.%.1]
 // CHECK:STDOUT:   %package_b.var: ref () = var package_b
 // CHECK:STDOUT:   %package_b: ref () = bind_name package_b, %package_b.var
 // CHECK:STDOUT:   %package.ref: <namespace> = name_ref package, package [template = package]
-// CHECK:STDOUT:   %B.ref.loc8: <function> = name_ref B, %.2 [template = %.2]
-// CHECK:STDOUT:   %.loc8_30: init () = call %B.ref.loc8()
-// CHECK:STDOUT:   assign %package_b.var, %.loc8_30
+// CHECK:STDOUT:   %B.ref.loc8: <error> = name_ref B, %import_ref
+// CHECK:STDOUT:   assign %package_b.var, <error>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @.1();
-// CHECK:STDOUT:
diff --git a/toolchain/check/testdata/packages/fail_todo_lazy_import_ref.carbon b/toolchain/check/testdata/var/fail_todo_import.carbon
similarity index 85%
rename from toolchain/check/testdata/packages/fail_todo_lazy_import_ref.carbon
rename to toolchain/check/testdata/var/fail_todo_import.carbon
index 8ff24993d9ce..8a633b9f89e5 100644
--- a/toolchain/check/testdata/packages/fail_todo_lazy_import_ref.carbon
+++ b/toolchain/check/testdata/var/fail_todo_import.carbon
@@ -6,7 +6,7 @@
 // then, update it whenever its target is implemented.
 //
 // AUTOUPDATE
-// CHECK:STDERR: implicit.impl.carbon: ERROR: Semantics TODO: `TODO: support BindName`.
+// CHECK:STDERR: implicit.impl.carbon: ERROR: Semantics TODO: `TODO: ResolveIfImportRefUnused for BindName`.
 
 // --- implicit.carbon
 
@@ -41,13 +41,13 @@ var a: () = a_ref;
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
-// CHECK:STDOUT:   package: <namespace> = namespace {.a_ref = %package.var, .a = %a} [template]
-// CHECK:STDOUT:   %package.var: ref <error> = var package
+// CHECK:STDOUT:   package: <namespace> = namespace {.a_ref = %import_ref, .a = %a} [template]
+// CHECK:STDOUT:   %import_ref: <error> = import_ref ir1, inst+2, used
 // CHECK:STDOUT:   %.loc4_9.1: () = tuple_literal ()
 // CHECK:STDOUT:   %.loc4_9.2: type = converted %.loc4_9.1, constants.%.1 [template = constants.%.1]
 // CHECK:STDOUT:   %a.var: ref () = var a
 // CHECK:STDOUT:   %a: ref () = bind_name a, %a.var
-// CHECK:STDOUT:   %a_ref.ref: ref <error> = name_ref a_ref, %package.var
+// CHECK:STDOUT:   %a_ref.ref: <error> = name_ref a_ref, %import_ref
 // CHECK:STDOUT:   assign %a.var, <error>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/lower/handle.cpp b/toolchain/lower/handle.cpp
index fadf9e526a84..5b24b0530853 100644
--- a/toolchain/lower/handle.cpp
+++ b/toolchain/lower/handle.cpp
@@ -206,6 +206,12 @@ auto HandleImportRefUnused(FunctionContext& /*context*/,
   FatalErrorIfEncountered(inst);
 }
 
+auto HandleImportRefUsed(FunctionContext& /*context*/,
+                         SemIR::InstId /*inst_id*/, SemIR::ImportRefUsed inst)
+    -> void {
+  FatalErrorIfEncountered(inst);
+}
+
 auto HandleInitializeFrom(FunctionContext& context, SemIR::InstId /*inst_id*/,
                           SemIR::InitializeFrom inst) -> void {
   auto storage_type_id = context.sem_ir().insts().Get(inst.dest_id).type_id();
diff --git a/toolchain/sem_ir/file.cpp b/toolchain/sem_ir/file.cpp
index b293962b9df9..3375c5041339 100644
--- a/toolchain/sem_ir/file.cpp
+++ b/toolchain/sem_ir/file.cpp
@@ -206,6 +206,7 @@ static auto GetTypePrecedence(InstKind kind) -> int {
     case BindSymbolicName::Kind:
     case Builtin::Kind:
     case ClassType::Kind:
+    case ImportRefUsed::Kind:
     case NameRef::Kind:
     case StructType::Kind:
     case TupleType::Kind:
@@ -355,6 +356,9 @@ auto File::StringifyTypeExpr(InstId outer_inst_id) const -> std::string {
         }
         break;
       }
+      case ImportRefUsed::Kind:
+        out << "<TODO: ImportRefUsed " << step.inst_id << ">";
+        break;
       case NameRef::Kind: {
         out << names().GetFormatted(inst.As<NameRef>().name_id);
         break;
@@ -510,6 +514,7 @@ auto GetExprCategory(const File& file, InstId inst_id) -> ExprCategory {
       case FunctionDecl::Kind:
       case Import::Kind:
       case ImportRefUnused::Kind:
+      case ImportRefUsed::Kind:
       case InterfaceDecl::Kind:
       case Namespace::Kind:
       case Return::Kind:
diff --git a/toolchain/sem_ir/formatter.cpp b/toolchain/sem_ir/formatter.cpp
index 71692a5c87e5..4bc17f538392 100644
--- a/toolchain/sem_ir/formatter.cpp
+++ b/toolchain/sem_ir/formatter.cpp
@@ -493,7 +493,8 @@ class InstNamer {
           add_inst_name("import");
           continue;
         }
-        case ImportRefUnused::Kind: {
+        case ImportRefUnused::Kind:
+        case ImportRefUsed::Kind: {
           add_inst_name("import_ref");
           continue;
         }
@@ -953,6 +954,12 @@ class Formatter {
     out_ << " " << inst.ir_id << ", " << inst.inst_id << ", unused";
   }
 
+  auto FormatInstructionRHS(ImportRefUsed inst) -> void {
+    // Don't format the inst_id because it refers to a different IR.
+    // TODO: Consider a better way to format the InstID from other IRs.
+    out_ << " " << inst.ir_id << ", " << inst.inst_id << ", used";
+  }
+
   auto FormatInstructionRHS(SpliceBlock inst) -> void {
     FormatArgs(inst.result_id);
     out_ << " {";
diff --git a/toolchain/sem_ir/inst_kind.def b/toolchain/sem_ir/inst_kind.def
index 675d1105e0d5..16ef241b9378 100644
--- a/toolchain/sem_ir/inst_kind.def
+++ b/toolchain/sem_ir/inst_kind.def
@@ -47,6 +47,7 @@ CARBON_SEM_IR_INST_KIND(FieldDecl)
 CARBON_SEM_IR_INST_KIND(FunctionDecl)
 CARBON_SEM_IR_INST_KIND(Import)
 CARBON_SEM_IR_INST_KIND(ImportRefUnused)
+CARBON_SEM_IR_INST_KIND(ImportRefUsed)
 CARBON_SEM_IR_INST_KIND(InitializeFrom)
 CARBON_SEM_IR_INST_KIND(InterfaceDecl)
 CARBON_SEM_IR_INST_KIND(IntLiteral)
diff --git a/toolchain/sem_ir/typed_insts.h b/toolchain/sem_ir/typed_insts.h
index dd04faab72b8..4157088c5f0f 100644
--- a/toolchain/sem_ir/typed_insts.h
+++ b/toolchain/sem_ir/typed_insts.h
@@ -416,6 +416,16 @@ struct Import {
   CrossRefIRId last_cross_ref_ir_id;
 };
 
+// Common representation for all kinds of `ImportRef*` node.
+struct AnyImportRef {
+  static constexpr InstKind Kinds[] = {InstKind::ImportRefUnused,
+                                       InstKind::ImportRefUsed};
+
+  InstKind kind;
+  CrossRefIRId ir_id;
+  InstId inst_id;
+};
+
 // An imported entity that hasn't yet been referenced. If referenced, it should
 // turn into an ImportRefUsed.
 // TODO: Add ImportRefUsed.
@@ -428,6 +438,17 @@ struct ImportRefUnused {
   InstId inst_id;
 };
 
+// An imported entity that has a reference, and thus should be emitted.
+struct ImportRefUsed {
+  // No parse node: any parse node logic must use the referenced IR.
+  static constexpr auto Kind =
+      InstKind::ImportRefUsed.Define<Parse::InvalidNodeId>("import_ref");
+
+  TypeId type_id;
+  CrossRefIRId ir_id;
+  InstId inst_id;
+};
+
 // Finalizes the initialization of `dest_id` from the initializer expression
 // `src_id`, by performing a final copy from source to destination, for types
 // whose initialization is not in-place.