diff --git a/toolchain/check/handle_binding_pattern.cpp b/toolchain/check/handle_binding_pattern.cpp
index 9e9a8f9bf692..89f29963496f 100644
--- a/toolchain/check/handle_binding_pattern.cpp
+++ b/toolchain/check/handle_binding_pattern.cpp
@@ -176,8 +176,8 @@ static auto HandleAnyBindingPattern(Context& context, Parse::NodeId node_id,
       context.decl_introducer_state_stack().innermost();
 
   auto form_id = node_kind == Parse::FormBindingPattern::Kind
-                     ? context.constant_values().Get(type_expr.inst_id)
-                     : SemIR::ConstantId::None;
+                     ? type_expr.inst_id
+                     : SemIR::InstId::None;
 
   // Adds a binding pattern for `node_id`, with the given kind and subpattern,
   // and adds its name to the current context. The subpattern must not be
diff --git a/toolchain/check/pattern.cpp b/toolchain/check/pattern.cpp
index 4fca17f1fdda..4bf736931dee 100644
--- a/toolchain/check/pattern.cpp
+++ b/toolchain/check/pattern.cpp
@@ -81,7 +81,7 @@ auto EndSubpattern(Context& context, NodeStack& node_stack) -> void {
 }
 
 auto AddBindingEntityName(Context& context, SemIR::NameId name_id,
-                          SemIR::ConstantId form_id, bool is_unused,
+                          SemIR::InstId form_id, bool is_unused,
                           BindingPhase phase) -> SemIR::EntityNameId {
   SemIR::EntityName entity_name = {
       .name_id = name_id,
@@ -213,11 +213,10 @@ auto AddParamPattern(Context& context, SemIR::LocId loc_id,
                                               .type_id = pattern_type_id,
                                               .pretty_name_id = name_id}));
 
-  auto entity_name_id =
-      AddBindingEntityName(context, name_id,
-                           /*form_id=*/SemIR::ConstantId::None,
-                           /*is_unused=*/false,
-                           /*phase=*/BindingPhase::Runtime);
+  auto entity_name_id = AddBindingEntityName(context, name_id,
+                                             /*form_id=*/SemIR::InstId::None,
+                                             /*is_unused=*/false,
+                                             /*phase=*/BindingPhase::Runtime);
   return AddBindingPattern(context, loc_id, type_expr_region_id,
                            {.kind = SemIR::WrapperBindingPattern::Kind,
                             .type_id = GetPatternType(context, type_id),
diff --git a/toolchain/check/pattern.h b/toolchain/check/pattern.h
index 9573b9ac65c0..3bba72304097 100644
--- a/toolchain/check/pattern.h
+++ b/toolchain/check/pattern.h
@@ -48,7 +48,7 @@ enum class BindingPhase { Template, Symbolic, Runtime };
 
 // Creates an entity name for a binding pattern with the given properties.
 auto AddBindingEntityName(Context& context, SemIR::NameId name_id,
-                          SemIR::ConstantId form_id, bool is_unused,
+                          SemIR::InstId form_id, bool is_unused,
                           BindingPhase phase) -> SemIR::EntityNameId;
 
 // Creates a binding pattern and the associated binding inst, and returns their
diff --git a/toolchain/check/pattern_match.cpp b/toolchain/check/pattern_match.cpp
index ec9c39f7c653..192663002636 100644
--- a/toolchain/check/pattern_match.cpp
+++ b/toolchain/check/pattern_match.cpp
@@ -300,8 +300,7 @@ static auto ConversionKindFor(Context& context, SemIR::Inst pattern,
       auto form_id = context.entity_names()
                          .Get(form_binding_pattern.entity_name_id)
                          .form_id;
-      auto form_inst_id = context.constant_values().GetInstId(form_id);
-      auto form_inst = context.insts().Get(form_inst_id);
+      auto form_inst = context.insts().Get(form_id);
 
       switch (form_inst.kind()) {
         case SemIR::InitForm::Kind:
@@ -320,9 +319,7 @@ static auto ConversionKindFor(Context& context, SemIR::Inst pattern,
       }
     }
     case CARBON_KIND(SemIR::FormParamPattern form_param_pattern): {
-      auto form_inst_id =
-          context.constant_values().GetInstId(form_param_pattern.form_id);
-      auto form_inst = context.insts().Get(form_inst_id);
+      auto form_inst = context.insts().Get(form_param_pattern.form_id);
 
       switch (form_inst.kind()) {
         case SemIR::InitForm::Kind:
@@ -429,9 +426,7 @@ static auto ParamKindFor(Context& context, SemIR::Inst param_pattern,
     case SemIR::ValueParamPattern::Kind:
       return SemIR::ValueParam::Kind;
     case CARBON_KIND(SemIR::FormParamPattern form_param_pattern): {
-      auto form_inst_id =
-          context.constant_values().GetInstId(form_param_pattern.form_id);
-      auto form_inst = context.insts().Get(form_inst_id);
+      auto form_inst = context.insts().Get(form_param_pattern.form_id);
       switch (form_inst.kind()) {
         case SemIR::InitForm::Kind:
         case SemIR::RefForm::Kind:
@@ -480,8 +475,7 @@ auto MatchContext::DoPreWork(State state, SemIR::AnyParamPattern param_pattern,
     case SemIR::FormParamPattern::Kind: {
       auto form_param_pattern =
           context_.insts().GetAs<SemIR::FormParamPattern>(entry.pattern_id);
-      if (!context_.constant_values().InstIs<SemIR::InitForm>(
-              form_param_pattern.form_id)) {
+      if (!context_.insts().Is<SemIR::InitForm>(form_param_pattern.form_id)) {
         break;
       }
       [[fallthrough]];
diff --git a/toolchain/check/testdata/basics/raw_sem_ir/cpp_interop.carbon b/toolchain/check/testdata/basics/raw_sem_ir/cpp_interop.carbon
index 8d612519b3bb..29e7405e234e 100644
--- a/toolchain/check/testdata/basics/raw_sem_ir/cpp_interop.carbon
+++ b/toolchain/check/testdata/basics/raw_sem_ir/cpp_interop.carbon
@@ -67,10 +67,10 @@ fn G(x: Cpp.X) {
 // CHECK:STDOUT:     name_scope50000001: {inst: inst50000011, parent_scope: name_scope0, has_error: false, extended_scopes: [], names: {name2: inst50000014, name3: inst5000002A, name4: inst5000004E}}
 // CHECK:STDOUT:     name_scope50000002: {inst: inst50000014, parent_scope: name_scope50000001, has_error: false, extended_scopes: [], names: {}}
 // CHECK:STDOUT:   entity_names:
-// CHECK:STDOUT:     entity_name50000000: {name: name1, parent_scope: name_scope<none>, index: -1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name50000001: {name: name1, parent_scope: name_scope<none>, index: -1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name50000002: {name: name1, parent_scope: name_scope<none>, index: -1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name50000003: {name: name4, parent_scope: name_scope50000001, index: -1, is_template: 0, is_unused: 0, form: constant<none>}
+// CHECK:STDOUT:     entity_name50000000: {name: name1, parent_scope: name_scope<none>, index: -1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name50000001: {name: name1, parent_scope: name_scope<none>, index: -1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name50000002: {name: name1, parent_scope: name_scope<none>, index: -1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name50000003: {name: name4, parent_scope: name_scope50000001, index: -1, is_template: 0, is_unused: 0, form: inst<none>}
 // CHECK:STDOUT:   cpp_global_vars:
 // CHECK:STDOUT:     cpp_global_var50000000: {key: {entity_name_id: entity_name50000003}, clang_decl_id: clang_decl_id50000008}
 // CHECK:STDOUT:   functions:
diff --git a/toolchain/check/testdata/basics/raw_sem_ir/multifile.carbon b/toolchain/check/testdata/basics/raw_sem_ir/multifile.carbon
index 068cacbe0763..d0813309c55c 100644
--- a/toolchain/check/testdata/basics/raw_sem_ir/multifile.carbon
+++ b/toolchain/check/testdata/basics/raw_sem_ir/multifile.carbon
@@ -139,7 +139,7 @@ fn B() {
 // CHECK:STDOUT:     name_scope0:     {inst: instF, parent_scope: name_scope<none>, has_error: false, extended_scopes: [], names: {name1: inst70000011, name0: inst70000012}}
 // CHECK:STDOUT:     name_scope70000001: {inst: inst70000011, parent_scope: name_scope0, has_error: false, extended_scopes: [], names: {name1: inst70000017}}
 // CHECK:STDOUT:   entity_names:
-// CHECK:STDOUT:     entity_name70000000: {name: name1, parent_scope: name_scope70000001, index: -1, is_template: 0, is_unused: 0, form: constant<none>}
+// CHECK:STDOUT:     entity_name70000000: {name: name1, parent_scope: name_scope70000001, index: -1, is_template: 0, is_unused: 0, form: inst<none>}
 // CHECK:STDOUT:   cpp_global_vars: {}
 // CHECK:STDOUT:   functions:
 // CHECK:STDOUT:     function70000000: {name: name0, parent_scope: name_scope0, call_param_patterns_id: inst_block_empty, call_params_id: inst_block_empty, body: [inst_block70000006]}
diff --git a/toolchain/check/testdata/basics/raw_sem_ir/multifile_with_textual_ir.carbon b/toolchain/check/testdata/basics/raw_sem_ir/multifile_with_textual_ir.carbon
index 4d9c74aef516..25a3d117a5fe 100644
--- a/toolchain/check/testdata/basics/raw_sem_ir/multifile_with_textual_ir.carbon
+++ b/toolchain/check/testdata/basics/raw_sem_ir/multifile_with_textual_ir.carbon
@@ -158,7 +158,7 @@ fn B() {
 // CHECK:STDOUT:     name_scope0:     {inst: instF, parent_scope: name_scope<none>, has_error: false, extended_scopes: [], names: {name1: inst70000011, name0: inst70000012}}
 // CHECK:STDOUT:     name_scope70000001: {inst: inst70000011, parent_scope: name_scope0, has_error: false, extended_scopes: [], names: {name1: inst70000017}}
 // CHECK:STDOUT:   entity_names:
-// CHECK:STDOUT:     entity_name70000000: {name: name1, parent_scope: name_scope70000001, index: -1, is_template: 0, is_unused: 0, form: constant<none>}
+// CHECK:STDOUT:     entity_name70000000: {name: name1, parent_scope: name_scope70000001, index: -1, is_template: 0, is_unused: 0, form: inst<none>}
 // CHECK:STDOUT:   cpp_global_vars: {}
 // CHECK:STDOUT:   functions:
 // CHECK:STDOUT:     function70000000: {name: name0, parent_scope: name_scope0, call_param_patterns_id: inst_block_empty, call_params_id: inst_block_empty, body: [inst_block70000006]}
diff --git a/toolchain/check/testdata/basics/raw_sem_ir/one_file.carbon b/toolchain/check/testdata/basics/raw_sem_ir/one_file.carbon
index 596f0faba9cc..9f0d047fdf3c 100644
--- a/toolchain/check/testdata/basics/raw_sem_ir/one_file.carbon
+++ b/toolchain/check/testdata/basics/raw_sem_ir/one_file.carbon
@@ -271,70 +271,70 @@ fn Foo[T:! type](p: T*) -> (T*, ()) {
 // CHECK:STDOUT:     name_scope7800000C: {inst: inst780000DB, parent_scope: name_scope78000001, has_error: false, extended_scopes: [], names: {}}
 // CHECK:STDOUT:     name_scope7800000D: {inst: inst7800011F, parent_scope: name_scope78000001, has_error: false, extended_scopes: [], names: {}}
 // CHECK:STDOUT:   entity_names:
-// CHECK:STDOUT:     entity_name78000000: {name: name(PeriodSelf), parent_scope: name_scope<none>, index: -1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000001: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000002: {name: name2, parent_scope: name_scope<none>, index: -1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000003: {name: name3, parent_scope: name_scope78000001, index: -1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000004: {name: name(SelfType), parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000005: {name: name4, parent_scope: name_scope78000003, index: -1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000006: {name: name(SelfType), parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000007: {name: name(SelfType), parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000008: {name: name(SelfValue), parent_scope: name_scope<none>, index: -1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000009: {name: name(SelfType), parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name7800000A: {name: name(SelfType), parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name7800000B: {name: name(SelfType), parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name7800000C: {name: name(SelfType), parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name7800000D: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name7800000E: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name7800000F: {name: name(SelfValue), parent_scope: name_scope<none>, index: -1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000010: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000011: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000012: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000013: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000014: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000015: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000016: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000017: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000018: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000019: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name7800001A: {name: name(SelfValue), parent_scope: name_scope<none>, index: -1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name7800001B: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name7800001C: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name7800001D: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name7800001E: {name: name(SelfValue), parent_scope: name_scope<none>, index: -1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name7800001F: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000020: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000021: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000022: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000023: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000024: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000025: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000026: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000027: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000028: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000029: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name7800002A: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name7800002B: {name: name6, parent_scope: name_scope<none>, index: 2, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name7800002C: {name: name6, parent_scope: name_scope<none>, index: 2, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name7800002D: {name: name(SelfValue), parent_scope: name_scope<none>, index: -1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name7800002E: {name: name6, parent_scope: name_scope<none>, index: 2, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name7800002F: {name: name6, parent_scope: name_scope<none>, index: 2, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000030: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000031: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000032: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000033: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000034: {name: name6, parent_scope: name_scope<none>, index: 2, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000035: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000036: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000037: {name: name6, parent_scope: name_scope<none>, index: 2, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000038: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name78000039: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name7800003A: {name: name6, parent_scope: name_scope<none>, index: 2, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name7800003B: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name7800003C: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name7800003D: {name: name6, parent_scope: name_scope<none>, index: 2, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name7800003E: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: constant<none>}
-// CHECK:STDOUT:     entity_name7800003F: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: constant<none>}
+// CHECK:STDOUT:     entity_name78000000: {name: name(PeriodSelf), parent_scope: name_scope<none>, index: -1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000001: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000002: {name: name2, parent_scope: name_scope<none>, index: -1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000003: {name: name3, parent_scope: name_scope78000001, index: -1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000004: {name: name(SelfType), parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000005: {name: name4, parent_scope: name_scope78000003, index: -1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000006: {name: name(SelfType), parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000007: {name: name(SelfType), parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000008: {name: name(SelfValue), parent_scope: name_scope<none>, index: -1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000009: {name: name(SelfType), parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name7800000A: {name: name(SelfType), parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name7800000B: {name: name(SelfType), parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name7800000C: {name: name(SelfType), parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name7800000D: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name7800000E: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name7800000F: {name: name(SelfValue), parent_scope: name_scope<none>, index: -1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000010: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000011: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000012: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000013: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000014: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000015: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000016: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000017: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000018: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000019: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name7800001A: {name: name(SelfValue), parent_scope: name_scope<none>, index: -1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name7800001B: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name7800001C: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name7800001D: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name7800001E: {name: name(SelfValue), parent_scope: name_scope<none>, index: -1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name7800001F: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000020: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000021: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000022: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000023: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000024: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000025: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000026: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000027: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000028: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000029: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name7800002A: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name7800002B: {name: name6, parent_scope: name_scope<none>, index: 2, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name7800002C: {name: name6, parent_scope: name_scope<none>, index: 2, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name7800002D: {name: name(SelfValue), parent_scope: name_scope<none>, index: -1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name7800002E: {name: name6, parent_scope: name_scope<none>, index: 2, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name7800002F: {name: name6, parent_scope: name_scope<none>, index: 2, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000030: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000031: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000032: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000033: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000034: {name: name6, parent_scope: name_scope<none>, index: 2, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000035: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000036: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000037: {name: name6, parent_scope: name_scope<none>, index: 2, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000038: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name78000039: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name7800003A: {name: name6, parent_scope: name_scope<none>, index: 2, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name7800003B: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name7800003C: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name7800003D: {name: name6, parent_scope: name_scope<none>, index: 2, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name7800003E: {name: name5, parent_scope: name_scope<none>, index: 1, is_template: 0, is_unused: 0, form: inst<none>}
+// CHECK:STDOUT:     entity_name7800003F: {name: name1, parent_scope: name_scope<none>, index: 0, is_template: 0, is_unused: 0, form: inst<none>}
 // CHECK:STDOUT:   cpp_global_vars: {}
 // CHECK:STDOUT:   functions:
 // CHECK:STDOUT:     function78000000: {name: name0, parent_scope: name_scope0, call_param_patterns_id: inst_block78000011, call_params_id: inst_block78000012, return_type_inst_id: inst78000030, return_form_inst_id: inst78000032, return_patterns_id: inst_block78000010, body: [inst_block78000019]}
diff --git a/toolchain/check/testdata/basics/raw_sem_ir/one_file_with_textual_ir.carbon b/toolchain/check/testdata/basics/raw_sem_ir/one_file_with_textual_ir.carbon
index 942f664a8aea..c15a716beb20 100644
--- a/toolchain/check/testdata/basics/raw_sem_ir/one_file_with_textual_ir.carbon
+++ b/toolchain/check/testdata/basics/raw_sem_ir/one_file_with_textual_ir.carbon
@@ -31,7 +31,7 @@ fn Foo(n: ()) -> ((), ()) {
 // CHECK:STDOUT:   name_scopes:
 // CHECK:STDOUT:     name_scope0:     {inst: instF, parent_scope: name_scope<none>, has_error: false, extended_scopes: [], names: {name0: inst5000002A}}
 // CHECK:STDOUT:   entity_names:
-// CHECK:STDOUT:     entity_name50000000: {name: name1, parent_scope: name_scope<none>, index: -1, is_template: 0, is_unused: 0, form: constant<none>}
+// CHECK:STDOUT:     entity_name50000000: {name: name1, parent_scope: name_scope<none>, index: -1, is_template: 0, is_unused: 0, form: inst<none>}
 // CHECK:STDOUT:   cpp_global_vars: {}
 // CHECK:STDOUT:   functions:
 // CHECK:STDOUT:     function50000000: {name: name0, parent_scope: name_scope0, call_param_patterns_id: inst_block5000000C, call_params_id: inst_block5000000D, return_type_inst_id: inst50000020, return_form_inst_id: inst50000021, return_patterns_id: inst_block5000000B, body: [inst_block50000010]}
diff --git a/toolchain/check/thunk.cpp b/toolchain/check/thunk.cpp
index 7c106dcf6111..e17f6e6ac704 100644
--- a/toolchain/check/thunk.cpp
+++ b/toolchain/check/thunk.cpp
@@ -74,9 +74,9 @@ static auto CloneBindingPattern(Context& context, SemIR::InstId pattern_id,
     phase = entity_name.is_template ? BindingPhase::Template
                                     : BindingPhase::Symbolic;
   }
-  pattern.entity_name_id = AddBindingEntityName(
-      context, entity_name.name_id, /*form_id=*/SemIR::ConstantId::None,
-      entity_name.is_unused, phase);
+  pattern.entity_name_id = AddBindingEntityName(context, entity_name.name_id,
+                                                /*form_id=*/SemIR::InstId::None,
+                                                entity_name.is_unused, phase);
   if (pattern.kind == SemIR::WrapperBindingPattern::Kind) {
     auto subpattern = context.insts().GetAs<SemIR::AnyLeafParamPattern>(
         pattern.subpattern_id);
diff --git a/toolchain/lower/file_context.cpp b/toolchain/lower/file_context.cpp
index 8f067344f3c1..a71456265287 100644
--- a/toolchain/lower/file_context.cpp
+++ b/toolchain/lower/file_context.cpp
@@ -683,10 +683,7 @@ auto FileContext::FunctionTypeInfoBuilder::TryHandleParameter(
   // corresponds to its form.
   if (auto form_param_pattern =
           param_pattern.TryAs<SemIR::FormParamPattern>()) {
-    CARBON_CHECK(!form_param_pattern->form_id.is_symbolic(), "TODO");
-    auto form_inst_id =
-        sem_ir.constant_values().GetInstId(form_param_pattern->form_id);
-    auto form_kind = sem_ir.insts().Get(form_inst_id).kind();
+    auto form_kind = sem_ir.insts().Get(form_param_pattern->form_id).kind();
     switch (form_kind) {
       case SemIR::InitForm::Kind:
         param_kind = SemIR::VarParamPattern::Kind;
diff --git a/toolchain/sem_ir/entity_name.h b/toolchain/sem_ir/entity_name.h
index dcbb1484d853..94b2ddc35fbf 100644
--- a/toolchain/sem_ir/entity_name.h
+++ b/toolchain/sem_ir/entity_name.h
@@ -64,7 +64,7 @@ struct EntityName : public Printable<EntityName> {
   //
   // TODO: Unify this with the previous three fields, which also represent form
   // information.
-  ConstantId form_id = ConstantId::None;
+  InstId form_id = InstId::None;
 };
 
 // Value store for EntityName. In addition to the regular ValueStore
diff --git a/toolchain/sem_ir/expr_info.cpp b/toolchain/sem_ir/expr_info.cpp
index 26533f038aa8..c6932e78e2e3 100644
--- a/toolchain/sem_ir/expr_info.cpp
+++ b/toolchain/sem_ir/expr_info.cpp
@@ -95,11 +95,7 @@ static auto GetExprCategoryImpl(const File* ir, InstId inst_id)
         }
       } else if constexpr (std::same_as<TypedInstT, FormBinding>) {
         auto form_id = ir->entity_names().Get(inst.entity_name_id).form_id;
-        if (form_id.is_symbolic()) {
-          return ExprCategory::Dependent;
-        }
-        auto form_inst_id = ir->constant_values().GetInstId(form_id);
-        auto form_inst = ir->insts().Get(form_inst_id);
+        auto form_inst = ir->insts().Get(form_id);
         CARBON_KIND_SWITCH(form_inst) {
           case InitForm::Kind:
             // A `var` binding pattern produces a `ref` binding.
diff --git a/toolchain/sem_ir/typed_insts.h b/toolchain/sem_ir/typed_insts.h
index 42f01edfd1e3..3fe3748c9a93 100644
--- a/toolchain/sem_ir/typed_insts.h
+++ b/toolchain/sem_ir/typed_insts.h
@@ -800,7 +800,7 @@ struct FormParamPattern {
 
   TypeId type_id;
   NameId pretty_name_id;
-  ConstantId form_id;
+  InstId form_id;
 };
 
 // The type `Core.Form`.