diff --git a/codegen/core/src/main/java/software/amazon/smithy/python/codegen/generators/SchemaGenerator.java b/codegen/core/src/main/java/software/amazon/smithy/python/codegen/generators/SchemaGenerator.java
index daaccada..4f97023a 100644
--- a/codegen/core/src/main/java/software/amazon/smithy/python/codegen/generators/SchemaGenerator.java
+++ b/codegen/core/src/main/java/software/amazon/smithy/python/codegen/generators/SchemaGenerator.java
@@ -162,6 +162,11 @@ private void writeSchemaMembers(PythonWriter writer, Shape shape) {
             for (MemberShape member : shape.members()) {
                 if (!generatedShapes.contains(member.getTarget()) && !Prelude.isPreludeShape(member.getTarget())) {
                     deferredMembers.put(member, index++);
+                    writer.write("""
+                            # This needs to reference a schema that isn't defined yet.
+                            # It will be populated with a non-null value at the end of the file.
+                            $S: None,
+                            """, member.getMemberName());
                     continue;
                 }
 
@@ -183,7 +188,6 @@ private void writeSchemaMembers(PythonWriter writer, Shape shape) {
                 writer.write("""
                         $S: {
                             "target": $T,
-                            "index": $L,
                             ${?hasTraits}
                             "traits": [
                                 ${C|}
@@ -193,7 +197,6 @@ private void writeSchemaMembers(PythonWriter writer, Shape shape) {
                         """,
                         member.getMemberName(),
                         targetSchemaSymbol,
-                        index,
                         writer.consumer(w -> writeTraits(w, traits)));
 
                 index++;
diff --git a/codegen/core/src/main/java/software/amazon/smithy/python/codegen/generators/SetupGenerator.java b/codegen/core/src/main/java/software/amazon/smithy/python/codegen/generators/SetupGenerator.java
index 021ba401..64e2e7a2 100644
--- a/codegen/core/src/main/java/software/amazon/smithy/python/codegen/generators/SetupGenerator.java
+++ b/codegen/core/src/main/java/software/amazon/smithy/python/codegen/generators/SetupGenerator.java
@@ -190,6 +190,9 @@ private static void writePyproject(
                     [tool.ruff.lint]
                     ignore = ["F841"]
 
+                    [tool.ruff.format]
+                    skip-magic-trailing-comma = true
+
                     [tool.pytest.ini_options]
                     python_classes = ["!Test"]
                     asyncio_mode = "auto"
diff --git a/designs/serialization.md b/designs/serialization.md
index e970260f..10858849 100644
--- a/designs/serialization.md
+++ b/designs/serialization.md
@@ -121,7 +121,6 @@ EXAMPLE_STRUCTURE_SCHEMA = Schema.collection(
     members={
         "member": {
             "target": INTEGER,
-            "index": 0,
             "traits": [
                 DefaultTrait(0),
             ],
diff --git a/packages/smithy-aws-event-stream/tests/unit/_private/__init__.py b/packages/smithy-aws-event-stream/tests/unit/_private/__init__.py
index 0ed16259..09162ecc 100644
--- a/packages/smithy-aws-event-stream/tests/unit/_private/__init__.py
+++ b/packages/smithy-aws-event-stream/tests/unit/_private/__init__.py
@@ -38,19 +38,18 @@
 SCHEMA_MESSAGE_EVENT = Schema.collection(
     id=ShapeID("smithy.example#MessageEvent"),
     members={
-        "boolHeader": {"index": 0, "target": BOOLEAN, "traits": [EVENT_HEADER_TRAIT]},
-        "byteHeader": {"index": 1, "target": BYTE, "traits": [EVENT_HEADER_TRAIT]},
-        "shortHeader": {"index": 2, "target": SHORT, "traits": [EVENT_HEADER_TRAIT]},
-        "intHeader": {"index": 3, "target": INTEGER, "traits": [EVENT_HEADER_TRAIT]},
-        "longHeader": {"index": 4, "target": LONG, "traits": [EVENT_HEADER_TRAIT]},
-        "blobHeader": {"index": 5, "target": BLOB, "traits": [EVENT_HEADER_TRAIT]},
-        "stringHeader": {"index": 6, "target": STRING, "traits": [EVENT_HEADER_TRAIT]},
+        "boolHeader": {"target": BOOLEAN, "traits": [EVENT_HEADER_TRAIT]},
+        "byteHeader": {"target": BYTE, "traits": [EVENT_HEADER_TRAIT]},
+        "shortHeader": {"target": SHORT, "traits": [EVENT_HEADER_TRAIT]},
+        "intHeader": {"target": INTEGER, "traits": [EVENT_HEADER_TRAIT]},
+        "longHeader": {"target": LONG, "traits": [EVENT_HEADER_TRAIT]},
+        "blobHeader": {"target": BLOB, "traits": [EVENT_HEADER_TRAIT]},
+        "stringHeader": {"target": STRING, "traits": [EVENT_HEADER_TRAIT]},
         "timestampHeader": {
-            "index": 7,
             "target": TIMESTAMP,
             "traits": [EVENT_HEADER_TRAIT],
         },
-        "bodyMember": {"index": 8, "target": STRING},
+        "bodyMember": {"target": STRING},
     },
 )
 
@@ -58,12 +57,10 @@
     id=ShapeID("smithy.example#PayloadEvent"),
     members={
         "header": {
-            "index": 0,
             "target": STRING,
             "traits": [EVENT_HEADER_TRAIT, REQUIRED_TRAIT],
         },
         "payload": {
-            "index": 1,
             "target": STRING,
             "traits": [EVENT_PAYLOAD_TRAIT, REQUIRED_TRAIT],
         },
@@ -74,12 +71,10 @@
     id=ShapeID("smithy.example#BlobPayloadEvent"),
     members={
         "header": {
-            "index": 0,
             "target": STRING,
             "traits": [EVENT_HEADER_TRAIT, REQUIRED_TRAIT],
         },
         "payload": {
-            "index": 1,
             "target": BLOB,
             "traits": [EVENT_PAYLOAD_TRAIT, REQUIRED_TRAIT],
         },
@@ -88,7 +83,7 @@
 
 SCHEMA_ERROR_EVENT = Schema.collection(
     id=ShapeID("smithy.example#ErrorEvent"),
-    members={"message": {"index": 0, "target": STRING, "traits": [REQUIRED_TRAIT]}},
+    members={"message": {"target": STRING, "traits": [REQUIRED_TRAIT]}},
     traits=[ERROR_TRAIT],
 )
 
@@ -97,21 +92,21 @@
     shape_type=ShapeType.UNION,
     traits=[STREAMING_TRAIT],
     members={
-        "message": {"index": 0, "target": SCHEMA_MESSAGE_EVENT},
-        "payload": {"index": 1, "target": SCHEMA_PAYLOAD_EVENT},
-        "blobPayload": {"index": 2, "target": SCHEMA_BLOB_PAYLOAD_EVENT},
-        "error": {"index": 3, "target": SCHEMA_ERROR_EVENT},
+        "message": {"target": SCHEMA_MESSAGE_EVENT},
+        "payload": {"target": SCHEMA_PAYLOAD_EVENT},
+        "blobPayload": {"target": SCHEMA_BLOB_PAYLOAD_EVENT},
+        "error": {"target": SCHEMA_ERROR_EVENT},
     },
 )
 
 SCHEMA_INITIAL_MESSAGE = Schema.collection(
     id=ShapeID("smithy.example#EventStreamOperationInputOutput"),
     members={
-        "message": {"index": 0, "target": STRING},
+        "message": {"target": STRING},
         # Event stream members will not be part of the operation input / output
         # shape schemas.
         # "stream": {
-        #     "index": 1,
+        #
         #     "target": SCHEMA_EVENT_STREAM
         # },
     },
diff --git a/packages/smithy-core/src/smithy_core/schemas.py b/packages/smithy-core/src/smithy_core/schemas.py
index a1b93d82..4d306a48 100644
--- a/packages/smithy-core/src/smithy_core/schemas.py
+++ b/packages/smithy-core/src/smithy_core/schemas.py
@@ -74,14 +74,13 @@ def __init__(
             traits = {}
         object.__setattr__(self, "traits", traits)
 
-        if members:
-            if isinstance(members, list):
-                m: dict[str, Schema] = {}
-                for member in members:
-                    m[member.expect_member_name()] = member
-                members = m
-        else:
+        if members is None:
             members = {}
+        elif isinstance(members, list):
+            m: dict[str, Schema] = {}
+            for member in sorted(members, key=lambda m: m.expect_member_index()):
+                m[member.expect_member_name()] = member
+            members = m
         object.__setattr__(self, "members", members)
 
         if member_target is not None:
@@ -194,7 +193,7 @@ def collection(
         id: ShapeID,
         shape_type: ShapeType = ShapeType.STRUCTURE,
         traits: list["Trait | DynamicTrait"] | None = None,
-        members: Mapping[str, "MemberSchema"] | None = None,
+        members: Mapping[str, "MemberSchema | None"] | None = None,
     ) -> Self:
         """Create a schema for a collection shape.
 
@@ -205,15 +204,23 @@ def collection(
             properties, map keys/values, and union variants. In contrast to the main
             constructor, this is a dict of member names to a simplified dict containing
             only ``traits`` and a ``target``. Member schemas will be generated from this.
+
+            If the value is None, it MUST be populated later. This is to allow a preservation
+            of modeled order without having to explicitly provide it and therefore generate
+            a ton of boilerplate.
         """
         struct_members: dict[str, Schema] = {}
         if members:
-            for k in members.keys():
+            for i, (k, member) in enumerate(members.items()):
+                if member is None:
+                    struct_members[k] = None  # type: ignore
+                    continue
+
                 struct_members[k] = cls.member(
                     id=id.with_member(k),
-                    target=members[k]["target"],
-                    index=members[k]["index"],
-                    member_traits=members[k].get("traits"),
+                    target=member["target"],
+                    index=i,
+                    member_traits=member.get("traits"),
                 )
 
         result = cls(
@@ -268,7 +275,6 @@ class MemberSchema(TypedDict):
     """
 
     target: Required[Schema]
-    index: Required[int]
     traits: NotRequired[list["Trait | DynamicTrait"]]
 
 
diff --git a/packages/smithy-core/tests/unit/test_documents.py b/packages/smithy-core/tests/unit/test_documents.py
index 8a1e3ccf..0b4ff052 100644
--- a/packages/smithy-core/tests/unit/test_documents.py
+++ b/packages/smithy-core/tests/unit/test_documents.py
@@ -402,7 +402,11 @@ def test_wrap_list_passes_schema_to_member_documents() -> None:
     list_schema = Schema.collection(
         id=id,
         shape_type=ShapeType.LIST,
-        members={"member": {"target": target_schema, "index": 0}},
+        members={
+            "member": {
+                "target": target_schema,
+            }
+        },
     )
     document = Document(["foo"], schema=list_schema)
     actual = document[0]._schema  # pyright: ignore[reportPrivateUsage]
@@ -421,7 +425,11 @@ def test_setitem_on_list_passes_schema_to_member_documents() -> None:
     list_schema = Schema.collection(
         id=id,
         shape_type=ShapeType.LIST,
-        members={"member": {"target": target_schema, "index": 0}},
+        members={
+            "member": {
+                "target": target_schema,
+            }
+        },
     )
     document = Document(["foo"], schema=list_schema)
     document[0] = "bar"
@@ -440,7 +448,11 @@ def test_wrap_structure_passes_schema_to_member_documents() -> None:
     target_schema = Schema(id=ShapeID("smithy.api#String"), shape_type=ShapeType.STRING)
     struct_schema = Schema.collection(
         id=id,
-        members={"stringMember": {"target": target_schema, "index": 0}},
+        members={
+            "stringMember": {
+                "target": target_schema,
+            }
+        },
     )
     document = Document({"stringMember": "foo"}, schema=struct_schema)
     actual = document["stringMember"]._schema  # pyright: ignore[reportPrivateUsage]
@@ -458,7 +470,11 @@ def test_setitem_on_structure_passes_schema_to_member_documents() -> None:
     target_schema = Schema(id=ShapeID("smithy.api#String"), shape_type=ShapeType.STRING)
     struct_schema = Schema.collection(
         id=id,
-        members={"stringMember": {"target": target_schema, "index": 0}},
+        members={
+            "stringMember": {
+                "target": target_schema,
+            }
+        },
     )
     document = Document({"stringMember": "foo"}, schema=struct_schema)
     document["stringMember"] = "spam"
@@ -478,8 +494,12 @@ def test_wrap_map_passes_schema_to_member_documents() -> None:
         id=id,
         shape_type=ShapeType.MAP,
         members={
-            "key": {"target": STRING, "index": 0},
-            "value": {"target": STRING, "index": 1},
+            "key": {
+                "target": STRING,
+            },
+            "value": {
+                "target": STRING,
+            },
         },
     )
     document = Document({"spam": "eggs"}, schema=map_schema)
@@ -496,8 +516,12 @@ def test_setitem_on_map_passes_schema_to_member_documents() -> None:
         id=id,
         shape_type=ShapeType.MAP,
         members={
-            "key": {"target": STRING, "index": 0},
-            "value": {"target": STRING, "index": 1},
+            "key": {
+                "target": STRING,
+            },
+            "value": {
+                "target": STRING,
+            },
         },
     )
     document = Document({"spam": "eggs"}, schema=map_schema)
@@ -517,47 +541,87 @@ def test_is_none():
 STRING_LIST_SCHEMA = Schema.collection(
     id=ShapeID("smithy.example#StringList"),
     shape_type=ShapeType.LIST,
-    members={"member": {"target": STRING, "index": 0}},
+    members={
+        "member": {
+            "target": STRING,
+        }
+    },
 )
 STRING_MAP_SCHEMA = Schema.collection(
     id=ShapeID("smithy.example#StringMap"),
     shape_type=ShapeType.MAP,
     members={
-        "key": {"target": STRING, "index": 0},
-        "value": {"target": STRING, "index": 1},
+        "key": {
+            "target": STRING,
+        },
+        "value": {
+            "target": STRING,
+        },
     },
 )
 SPARSE_STRING_LIST_SCHEMA = Schema.collection(
     id=ShapeID("smithy.example#StringList"),
     shape_type=ShapeType.LIST,
-    members={"member": {"target": STRING, "index": 0}},
+    members={
+        "member": {
+            "target": STRING,
+        }
+    },
     traits=[SparseTrait()],
 )
 SPARSE_STRING_MAP_SCHEMA = Schema.collection(
     id=ShapeID("smithy.example#StringMap"),
     shape_type=ShapeType.MAP,
     members={
-        "key": {"target": STRING, "index": 0},
-        "value": {"target": STRING, "index": 1},
+        "key": {
+            "target": STRING,
+        },
+        "value": {
+            "target": STRING,
+        },
     },
     traits=[SparseTrait()],
 )
 SCHEMA: Schema = Schema.collection(
     id=ShapeID("smithy.example#DocumentSerdeShape"),
     members={
-        "booleanMember": {"target": BOOLEAN, "index": 0},
-        "integerMember": {"target": INTEGER, "index": 1},
-        "floatMember": {"target": FLOAT, "index": 2},
-        "bigDecimalMember": {"target": BIG_DECIMAL, "index": 3},
-        "stringMember": {"target": STRING, "index": 4},
-        "blobMember": {"target": BLOB, "index": 5},
-        "timestampMember": {"target": TIMESTAMP, "index": 6},
-        "documentMember": {"target": DOCUMENT, "index": 7},
-        "listMember": {"target": STRING_LIST_SCHEMA, "index": 8},
-        "mapMember": {"target": STRING_MAP_SCHEMA, "index": 9},
-        # Index 10 is set below because it's a self-referential member.
-        "sparseListMember": {"target": SPARSE_STRING_LIST_SCHEMA, "index": 11},
-        "sparseMapMember": {"target": SPARSE_STRING_MAP_SCHEMA, "index": 12},
+        "booleanMember": {
+            "target": BOOLEAN,
+        },
+        "integerMember": {
+            "target": INTEGER,
+        },
+        "floatMember": {
+            "target": FLOAT,
+        },
+        "bigDecimalMember": {
+            "target": BIG_DECIMAL,
+        },
+        "stringMember": {
+            "target": STRING,
+        },
+        "blobMember": {
+            "target": BLOB,
+        },
+        "timestampMember": {
+            "target": TIMESTAMP,
+        },
+        "documentMember": {
+            "target": DOCUMENT,
+        },
+        "listMember": {
+            "target": STRING_LIST_SCHEMA,
+        },
+        "mapMember": {
+            "target": STRING_MAP_SCHEMA,
+        },
+        "structMember": None,
+        "sparseListMember": {
+            "target": SPARSE_STRING_LIST_SCHEMA,
+        },
+        "sparseMapMember": {
+            "target": SPARSE_STRING_MAP_SCHEMA,
+        },
     },
 )
 SCHEMA.members["structMember"] = Schema.member(
diff --git a/packages/smithy-core/tests/unit/test_schemas.py b/packages/smithy-core/tests/unit/test_schemas.py
index 212a98a4..b15fe472 100644
--- a/packages/smithy-core/tests/unit/test_schemas.py
+++ b/packages/smithy-core/tests/unit/test_schemas.py
@@ -97,7 +97,7 @@ def test_collection_constructor():
     )
     schema = Schema.collection(
         id=ID,
-        members={member_name: {"target": STRING, "index": 0, "traits": [trait_value]}},
+        members={member_name: {"target": STRING, "traits": [trait_value]}},
     )
     assert schema.members == {member_name: member}
 
@@ -109,7 +109,7 @@ def test_member_constructor():
             SensitiveTrait(),
             DynamicTrait(id=ShapeID("smithy.example#foo"), document_value="bar"),
         ],
-        members={"spam": {"target": STRING, "index": 0}},
+        members={"spam": {"target": STRING}},
     )
 
     member_id = ShapeID("smithy.example#Spam$eggs")
@@ -164,7 +164,7 @@ def test_member_constructor_asserts_target_is_not_member():
 def test_contains(item: Any, contains: bool):
     schema = Schema.collection(
         id=ID,
-        members={"baz": {"target": STRING, "index": 0}},
+        members={"baz": {"target": STRING}},
         traits=[SensitiveTrait()],
     )
 
diff --git a/packages/smithy-core/tests/unit/test_type_registry.py b/packages/smithy-core/tests/unit/test_type_registry.py
index 6a2a4ffc..7375abaa 100644
--- a/packages/smithy-core/tests/unit/test_type_registry.py
+++ b/packages/smithy-core/tests/unit/test_type_registry.py
@@ -63,7 +63,7 @@ class TestShape(DeserializeableShape):
     __test__ = False
     schema = Schema.collection(
         id=ShapeID("com.example#Test"),
-        members={"value": {"index": 0, "target": STRING, "traits": [RequiredTrait()]}},
+        members={"value": {"target": STRING, "traits": [RequiredTrait()]}},
     )
 
     def __init__(self, value: str):
diff --git a/packages/smithy-http/src/smithy_http/bindings.py b/packages/smithy-http/src/smithy_http/bindings.py
index de0eee09..39f88f30 100644
--- a/packages/smithy-http/src/smithy_http/bindings.py
+++ b/packages/smithy-http/src/smithy_http/bindings.py
@@ -76,13 +76,13 @@ def __init__(self, struct: Schema, response_status: int) -> None:
         self.response_status = response_status
         found_body = False
         found_payload = False
-        self.bindings = [Binding.BODY] * len(struct.members)
+        self.bindings = []
         self.payload_member = None
         self.event_stream_member = None
 
         for member in struct.members.values():
             binding = self._do_match(member)
-            self.bindings[member.expect_member_index()] = binding
+            self.bindings.append(binding)
             found_body = (
                 found_body or binding is Binding.BODY or binding is Binding.HOST
             )
diff --git a/packages/smithy-http/tests/unit/test_bindings.py b/packages/smithy-http/tests/unit/test_bindings.py
index 5d84b2e0..f4820dcc 100644
--- a/packages/smithy-http/tests/unit/test_bindings.py
+++ b/packages/smithy-http/tests/unit/test_bindings.py
@@ -21,7 +21,7 @@
 
 PAYLOAD_BINDING = Schema.collection(
     id=ShapeID("com.example#Payload"),
-    members={"payload": {"index": 0, "target": STRING, "traits": [HTTPPayloadTrait()]}},
+    members={"payload": {"target": STRING, "traits": [HTTPPayloadTrait()]}},
 )
 
 EVENT_STREAM_SCHEMA = Schema.collection(
@@ -29,7 +29,6 @@
     shape_type=ShapeType.UNION,
     members={
         "stream": {
-            "index": 0,
             "target": Schema.collection(id=ShapeID("com.example#Event")),
         }
     },
@@ -37,41 +36,38 @@
 )
 EVENT_STREAM_BINDING = Schema.collection(
     id=ShapeID("com.example#Events"),
-    members={"stream": {"index": 0, "target": EVENT_STREAM_SCHEMA}},
+    members={"stream": {"target": EVENT_STREAM_SCHEMA}},
 )
 
 STRING_MAP = Schema.collection(
     id=ShapeID("com.example#StringMap"),
     shape_type=ShapeType.MAP,
     members={
-        "key": {"index": 0, "target": STRING},
-        "value": {"index": 0, "target": STRING},
+        "key": {"target": STRING},
+        "value": {"target": STRING},
     },
 )
 
 GENERAL_BINDINGS = Schema.collection(
     id=ShapeID("com.example#BodyBindings"),
     members={
-        "label": {"index": 0, "target": STRING, "traits": [HTTPLabelTrait()]},
-        "query": {"index": 1, "target": STRING, "traits": [HTTPQueryTrait()]},
+        "label": {"target": STRING, "traits": [HTTPLabelTrait()]},
+        "query": {"target": STRING, "traits": [HTTPQueryTrait()]},
         "queryParams": {
-            "index": 2,
             "target": STRING_MAP,
             "traits": [HTTPQueryParamsTrait()],
         },
-        "header": {"index": 3, "target": STRING, "traits": [HTTPHeaderTrait()]},
+        "header": {"target": STRING, "traits": [HTTPHeaderTrait()]},
         "prefixHeaders": {
-            "index": 4,
             "target": STRING_MAP,
             "traits": [HTTPPrefixHeadersTrait("foo")],
         },
-        "hostLabel": {"index": 5, "target": STRING, "traits": [HostLabelTrait()]},
+        "hostLabel": {"target": STRING, "traits": [HostLabelTrait()]},
         "status": {
-            "index": 6,
             "target": INTEGER,
             "traits": [HTTPResponseCodeTrait()],
         },
-        "body": {"index": 7, "target": STRING},
+        "body": {"target": STRING},
     },
 )
 
diff --git a/packages/smithy-http/tests/unit/test_serializers.py b/packages/smithy-http/tests/unit/test_serializers.py
index 0dd5eea6..d477a7e9 100644
--- a/packages/smithy-http/tests/unit/test_serializers.py
+++ b/packages/smithy-http/tests/unit/test_serializers.py
@@ -51,39 +51,38 @@
 BOOLEAN_LIST = Schema.collection(
     id=ShapeID("com.smithy#BooleanList"),
     shape_type=ShapeType.LIST,
-    members={"member": {"index": 0, "target": BOOLEAN}},
+    members={"member": {"target": BOOLEAN}},
 )
 STRING_LIST = Schema.collection(
     id=ShapeID("com.smithy#StringList"),
     shape_type=ShapeType.LIST,
-    members={"member": {"index": 0, "target": STRING}},
+    members={"member": {"target": STRING}},
 )
 INTEGER_LIST = Schema.collection(
     id=ShapeID("com.smithy#IntegerList"),
     shape_type=ShapeType.LIST,
-    members={"member": {"index": 0, "target": INTEGER}},
+    members={"member": {"target": INTEGER}},
 )
 FLOAT_LIST = Schema.collection(
     id=ShapeID("com.smithy#FloatList"),
     shape_type=ShapeType.LIST,
-    members={"member": {"index": 0, "target": FLOAT}},
+    members={"member": {"target": FLOAT}},
 )
 BIG_DECIMAL_LIST = Schema.collection(
     id=ShapeID("com.smithy#BigDecimalList"),
     shape_type=ShapeType.LIST,
-    members={"member": {"index": 0, "target": BIG_DECIMAL}},
+    members={"member": {"target": BIG_DECIMAL}},
 )
 BARE_TIMESTAMP_LIST = Schema.collection(
     id=ShapeID("com.smithy#BareTimestampList"),
     shape_type=ShapeType.LIST,
-    members={"member": {"index": 0, "target": TIMESTAMP}},
+    members={"member": {"target": TIMESTAMP}},
 )
 HTTP_DATE_TIMESTAMP_LIST = Schema.collection(
     id=ShapeID("com.smithy#HttpDateTimestampList"),
     shape_type=ShapeType.LIST,
     members={
         "member": {
-            "index": 0,
             "target": TIMESTAMP,
             "traits": [TimestampFormatTrait("http-date")],
         }
@@ -94,7 +93,6 @@
     shape_type=ShapeType.LIST,
     members={
         "member": {
-            "index": 0,
             "target": TIMESTAMP,
             "traits": [TimestampFormatTrait("date-time")],
         }
@@ -105,7 +103,6 @@
     shape_type=ShapeType.LIST,
     members={
         "member": {
-            "index": 0,
             "target": TIMESTAMP,
             "traits": [TimestampFormatTrait("epoch-seconds")],
         }
@@ -115,8 +112,8 @@
     id=ShapeID("com.smithy#StringMap"),
     shape_type=ShapeType.MAP,
     members={
-        "key": {"index": 0, "target": STRING},
-        "value": {"index": 1, "target": STRING},
+        "key": {"target": STRING},
+        "value": {"target": STRING},
     },
 )
 
@@ -159,62 +156,50 @@ def __init_subclass__(
             id=id,
             members={
                 "boolean_member": {
-                    "index": 0,
                     "target": BOOLEAN,
                     "traits": [trait("boolean")],
                 },
                 "boolean_list_member": {
-                    "index": 1,
                     "target": BOOLEAN_LIST,
                     "traits": [trait("booleanList")],
                 },
                 "integer_member": {
-                    "index": 2,
                     "target": INTEGER,
                     "traits": [trait("integer")],
                 },
                 "integer_list_member": {
-                    "index": 3,
                     "target": INTEGER_LIST,
                     "traits": [trait("integerList")],
                 },
                 "float_member": {
-                    "index": 4,
                     "target": FLOAT,
                     "traits": [trait("float")],
                 },
                 "float_list_member": {
-                    "index": 5,
                     "target": FLOAT_LIST,
                     "traits": [trait("floatList")],
                 },
                 "big_decimal_member": {
-                    "index": 6,
                     "target": BIG_DECIMAL,
                     "traits": [trait("bigDecimal")],
                 },
                 "big_decimal_list_member": {
-                    "index": 7,
                     "target": BIG_DECIMAL_LIST,
                     "traits": [trait("bigDecimalList")],
                 },
                 "string_member": {
-                    "index": 8,
                     "target": STRING,
                     "traits": [trait("string")],
                 },
                 "string_list_member": {
-                    "index": 9,
                     "target": STRING_LIST,
                     "traits": [trait("stringList")],
                 },
                 "default_timestamp_member": {
-                    "index": 10,
                     "target": TIMESTAMP,
                     "traits": [trait("defaultTimestamp")],
                 },
                 "http_date_timestamp_member": {
-                    "index": 11,
                     "target": TIMESTAMP,
                     "traits": [
                         trait("httpDateTimestamp"),
@@ -222,12 +207,10 @@ def __init_subclass__(
                     ],
                 },
                 "http_date_list_timestamp_member": {
-                    "index": 12,
                     "target": HTTP_DATE_TIMESTAMP_LIST,
                     "traits": [trait("httpDateListTimestamp")],
                 },
                 "date_time_timestamp_member": {
-                    "index": 13,
                     "target": TIMESTAMP,
                     "traits": [
                         trait("dateTimeTimestamp"),
@@ -235,12 +218,10 @@ def __init_subclass__(
                     ],
                 },
                 "date_time_list_timestamp_member": {
-                    "index": 14,
                     "target": DATE_TIME_TIMESTAMP_LIST,
                     "traits": [trait("dateTimeListTimestamp")],
                 },
                 "epoch_timestamp_member": {
-                    "index": 15,
                     "target": TIMESTAMP,
                     "traits": [
                         trait("epochTimestamp"),
@@ -248,12 +229,10 @@ def __init_subclass__(
                     ],
                 },
                 "epoch_list_timestamp_member": {
-                    "index": 16,
                     "target": EPOCH_TIMESTAMP_LIST,
                     "traits": [trait("epochListTimestamp")],
                 },
                 "string_map_member": {
-                    "index": 17,
                     "target": STRING_MAP,
                     "traits": [map_trait],
                 },
@@ -527,9 +506,7 @@ class HTTPResponseCode:
     ID: ClassVar[ShapeID] = ShapeID("com.smithy#HTTPResponseCode")
     SCHEMA: ClassVar[Schema] = Schema.collection(
         id=ID,
-        members={
-            "code": {"index": 0, "target": INTEGER, "traits": [HTTPResponseCodeTrait()]}
-        },
+        members={"code": {"target": INTEGER, "traits": [HTTPResponseCodeTrait()]}},
     )
 
     def serialize(self, serializer: ShapeSerializer) -> None:
@@ -564,11 +541,10 @@ class HTTPImplicitPayload:
         id=ID,
         members={
             "header": {
-                "index": 0,
                 "target": STRING,
                 "traits": [HTTPHeaderTrait("header")],
             },
-            "payload_member": {"index": 1, "target": STRING},
+            "payload_member": {"target": STRING},
         },
     )
 
@@ -610,9 +586,7 @@ class HTTPStringPayload:
     ID: ClassVar[ShapeID] = ShapeID("com.smithy#HTTPStringPayload")
     SCHEMA: ClassVar[Schema] = Schema.collection(
         id=ID,
-        members={
-            "payload": {"index": 0, "target": STRING, "traits": [HTTPPayloadTrait()]}
-        },
+        members={"payload": {"target": STRING, "traits": [HTTPPayloadTrait()]}},
     )
 
     def serialize(self, serializer: ShapeSerializer) -> None:
@@ -644,9 +618,7 @@ class HTTPBlobPayload:
     ID: ClassVar[ShapeID] = ShapeID("com.smithy#HTTPBlobPayload")
     SCHEMA: ClassVar[Schema] = Schema.collection(
         id=ID,
-        members={
-            "payload": {"index": 0, "target": BLOB, "traits": [HTTPPayloadTrait()]}
-        },
+        members={"payload": {"target": BLOB, "traits": [HTTPPayloadTrait()]}},
     )
 
     def serialize(self, serializer: ShapeSerializer) -> None:
@@ -680,7 +652,6 @@ class HTTPStreamingPayload:
         id=ID,
         members={
             "payload": {
-                "index": 0,
                 "target": BLOB,
                 "traits": [HTTPPayloadTrait(), StreamingTrait()],
             }
@@ -720,7 +691,6 @@ class HTTPStructuredPayload:
         id=ID,
         members={
             "payload": {
-                "index": 0,
                 "target": HTTPStringPayload.SCHEMA,
                 "traits": [HTTPPayloadTrait()],
             }
@@ -756,7 +726,7 @@ class HTTPStringLabel:
     ID: ClassVar[ShapeID] = ShapeID("com.smithy#HTTPStringLabel")
     SCHEMA: ClassVar[Schema] = Schema.collection(
         id=ID,
-        members={"label": {"index": 0, "target": STRING, "traits": [HTTPLabelTrait()]}},
+        members={"label": {"target": STRING, "traits": [HTTPLabelTrait()]}},
     )
 
     def serialize(self, serializer: ShapeSerializer) -> None:
@@ -788,9 +758,7 @@ class HTTPIntegerLabel:
     ID: ClassVar[ShapeID] = ShapeID("com.smithy#HTTPIntegerLabel")
     SCHEMA: ClassVar[Schema] = Schema.collection(
         id=ID,
-        members={
-            "label": {"index": 0, "target": INTEGER, "traits": [HTTPLabelTrait()]}
-        },
+        members={"label": {"target": INTEGER, "traits": [HTTPLabelTrait()]}},
     )
 
     def serialize(self, serializer: ShapeSerializer) -> None:
@@ -822,7 +790,7 @@ class HTTPFloatLabel:
     ID: ClassVar[ShapeID] = ShapeID("com.smithy#HTTPFloatLabel")
     SCHEMA: ClassVar[Schema] = Schema.collection(
         id=ID,
-        members={"label": {"index": 0, "target": FLOAT, "traits": [HTTPLabelTrait()]}},
+        members={"label": {"target": FLOAT, "traits": [HTTPLabelTrait()]}},
     )
 
     def serialize(self, serializer: ShapeSerializer) -> None:
@@ -854,9 +822,7 @@ class HTTPBigDecimalLabel:
     ID: ClassVar[ShapeID] = ShapeID("com.smithy#HTTPBigDecimalLabel")
     SCHEMA: ClassVar[Schema] = Schema.collection(
         id=ID,
-        members={
-            "label": {"index": 0, "target": BIG_DECIMAL, "traits": [HTTPLabelTrait()]}
-        },
+        members={"label": {"target": BIG_DECIMAL, "traits": [HTTPLabelTrait()]}},
     )
 
     def serialize(self, serializer: ShapeSerializer) -> None:
@@ -888,9 +854,7 @@ class HTTPBooleanLabel:
     ID: ClassVar[ShapeID] = ShapeID("com.smithy#HTTPBooleanLabel")
     SCHEMA: ClassVar[Schema] = Schema.collection(
         id=ID,
-        members={
-            "label": {"index": 0, "target": BOOLEAN, "traits": [HTTPLabelTrait()]}
-        },
+        members={"label": {"target": BOOLEAN, "traits": [HTTPLabelTrait()]}},
     )
 
     def serialize(self, serializer: ShapeSerializer) -> None:
@@ -922,9 +886,7 @@ class HTTPDefaultTimestampLabel:
     ID: ClassVar[ShapeID] = ShapeID("com.smithy#HTTPDefaultTimestampLabel")
     SCHEMA: ClassVar[Schema] = Schema.collection(
         id=ID,
-        members={
-            "label": {"index": 0, "target": TIMESTAMP, "traits": [HTTPLabelTrait()]}
-        },
+        members={"label": {"target": TIMESTAMP, "traits": [HTTPLabelTrait()]}},
     )
 
     def serialize(self, serializer: ShapeSerializer) -> None:
@@ -958,7 +920,6 @@ class HTTPEpochTimestampLabel:
         id=ID,
         members={
             "label": {
-                "index": 0,
                 "target": TIMESTAMP,
                 "traits": [HTTPLabelTrait(), TimestampFormatTrait("epoch-seconds")],
             }
@@ -996,7 +957,6 @@ class HTTPDateTimestampLabel:
         id=ID,
         members={
             "label": {
-                "index": 0,
                 "target": TIMESTAMP,
                 "traits": [HTTPLabelTrait(), TimestampFormatTrait("http-date")],
             }
@@ -1034,7 +994,6 @@ class HTTPDateTimeTimestampLabel:
         id=ID,
         members={
             "label": {
-                "index": 0,
                 "target": TIMESTAMP,
                 "traits": [HTTPLabelTrait(), TimestampFormatTrait("date-time")],
             }
@@ -1072,7 +1031,6 @@ class HostLabel:
         id=ID,
         members={
             "label": {
-                "index": 0,
                 "target": STRING,
                 "traits": [HostLabelTrait()],
             }
diff --git a/packages/smithy-json/tests/unit/__init__.py b/packages/smithy-json/tests/unit/__init__.py
index 9cdff545..34d1362e 100644
--- a/packages/smithy-json/tests/unit/__init__.py
+++ b/packages/smithy-json/tests/unit/__init__.py
@@ -23,67 +23,103 @@
 STRING_LIST_SCHEMA = Schema.collection(
     id=ShapeID("smithy.example#StringList"),
     shape_type=ShapeType.LIST,
-    members={"member": {"target": STRING, "index": 0}},
+    members={
+        "member": {
+            "target": STRING,
+        }
+    },
 )
 STRING_MAP_SCHEMA = Schema.collection(
     id=ShapeID("smithy.example#StringMap"),
     shape_type=ShapeType.MAP,
     members={
-        "key": {"target": STRING, "index": 0},
-        "value": {"target": STRING, "index": 1},
+        "key": {
+            "target": STRING,
+        },
+        "value": {
+            "target": STRING,
+        },
     },
 )
 SPARSE_STRING_LIST_SCHEMA = Schema.collection(
     id=ShapeID("smithy.example#StringList"),
     shape_type=ShapeType.LIST,
-    members={"member": {"target": STRING, "index": 0}},
+    members={
+        "member": {
+            "target": STRING,
+        }
+    },
     traits=[SparseTrait()],
 )
 SPARSE_STRING_MAP_SCHEMA = Schema.collection(
     id=ShapeID("smithy.example#StringMap"),
     shape_type=ShapeType.MAP,
     members={
-        "key": {"target": STRING, "index": 0},
-        "value": {"target": STRING, "index": 1},
+        "key": {
+            "target": STRING,
+        },
+        "value": {
+            "target": STRING,
+        },
     },
     traits=[SparseTrait()],
 )
 SCHEMA: Schema = Schema.collection(
     id=ShapeID("smithy.example#SerdeShape"),
     members={
-        "booleanMember": {"target": BOOLEAN, "index": 0},
-        "integerMember": {"target": INTEGER, "index": 1},
-        "floatMember": {"target": FLOAT, "index": 2},
-        "bigDecimalMember": {"target": BIG_DECIMAL, "index": 3},
-        "stringMember": {"target": STRING, "index": 4},
+        "booleanMember": {
+            "target": BOOLEAN,
+        },
+        "integerMember": {
+            "target": INTEGER,
+        },
+        "floatMember": {
+            "target": FLOAT,
+        },
+        "bigDecimalMember": {
+            "target": BIG_DECIMAL,
+        },
+        "stringMember": {
+            "target": STRING,
+        },
         "jsonNameMember": {
             "target": STRING,
             "traits": [JSONNameTrait("jsonName")],
-            "index": 5,
         },
-        "blobMember": {"target": BLOB, "index": 6},
-        "timestampMember": {"target": TIMESTAMP, "index": 7},
+        "blobMember": {
+            "target": BLOB,
+        },
+        "timestampMember": {
+            "target": TIMESTAMP,
+        },
         "dateTimeMember": {
             "target": TIMESTAMP,
             "traits": [TimestampFormatTrait("date-time")],
-            "index": 8,
         },
         "httpDateMember": {
             "target": TIMESTAMP,
             "traits": [TimestampFormatTrait("http-date")],
-            "index": 9,
         },
         "epochSecondsMember": {
             "target": TIMESTAMP,
             "traits": [TimestampFormatTrait("epoch-seconds")],
-            "index": 10,
         },
-        "documentMember": {"target": DOCUMENT, "index": 11},
-        "listMember": {"target": STRING_LIST_SCHEMA, "index": 12},
-        "mapMember": {"target": STRING_MAP_SCHEMA, "index": 13},
-        # Index 14 is set below because it's a self-referential member.
-        "sparseListMember": {"target": SPARSE_STRING_LIST_SCHEMA, "index": 15},
-        "sparseMapMember": {"target": SPARSE_STRING_MAP_SCHEMA, "index": 16},
+        "documentMember": {
+            "target": DOCUMENT,
+        },
+        "listMember": {
+            "target": STRING_LIST_SCHEMA,
+        },
+        "mapMember": {
+            "target": STRING_MAP_SCHEMA,
+        },
+        "structMember": None,
+        "sparseListMember": {
+            "target": SPARSE_STRING_LIST_SCHEMA,
+        },
+        "sparseMapMember": {
+            "target": SPARSE_STRING_MAP_SCHEMA,
+        },
     },
 )
 SCHEMA.members["structMember"] = Schema.member(