diff --git a/packages/util-dynamodb/src/marshall.spec.ts b/packages/util-dynamodb/src/marshall.spec.ts
index ea16c3cb2d03..9a1f784a43b5 100644
--- a/packages/util-dynamodb/src/marshall.spec.ts
+++ b/packages/util-dynamodb/src/marshall.spec.ts
@@ -1,21 +1,15 @@
-import { convertToAttr } from "./convertToAttr";
-import { marshall } from "./marshall";
+import { AttributeValue } from "@aws-sdk/client-dynamodb";
 
-jest.mock("./convertToAttr");
+import { marshall } from "./marshall";
+import { NumberValue } from "./NumberValue";
 
 describe("marshall", () => {
-  const mockOutput = { S: "mockOutput" };
-  (convertToAttr as jest.Mock).mockReturnValue({ M: mockOutput });
-
-  afterEach(() => {
-    jest.clearAllMocks();
-  });
-
   it("with object as an input", () => {
     const input = { a: "A", b: "B" };
-    expect(marshall(input)).toEqual(mockOutput);
-    expect(convertToAttr).toHaveBeenCalledTimes(1);
-    expect(convertToAttr).toHaveBeenCalledWith(input, undefined);
+    expect(marshall(input)).toEqual({
+      a: { S: "A" },
+      b: { S: "B" },
+    });
   });
 
   ["convertEmptyValues", "removeUndefinedValues"].forEach((option) => {
@@ -23,9 +17,10 @@ describe("marshall", () => {
       [false, true].forEach((value) => {
         it(`passes ${value} to convertToAttr`, () => {
           const input = { a: "A", b: "B" };
-          expect(marshall(input, { [option]: value })).toEqual(mockOutput);
-          expect(convertToAttr).toHaveBeenCalledTimes(1);
-          expect(convertToAttr).toHaveBeenCalledWith(input, { [option]: value });
+          expect(marshall(input, { [option]: value })).toEqual({
+            a: { S: "A" },
+            b: { S: "B" },
+          });
         });
       });
     });
@@ -35,9 +30,10 @@ describe("marshall", () => {
     type TestInputType = { a: string; b: string };
     const input: TestInputType = { a: "A", b: "B" };
 
-    expect(marshall(input)).toEqual(mockOutput);
-    expect(convertToAttr).toHaveBeenCalledTimes(1);
-    expect(convertToAttr).toHaveBeenCalledWith(input, undefined);
+    expect(marshall(input)).toEqual({
+      a: { S: "A" },
+      b: { S: "B" },
+    });
   });
 
   it("with Interface as an input", () => {
@@ -47,9 +43,145 @@ describe("marshall", () => {
     }
     const input: TestInputInterface = { a: "A", b: "B" };
 
-    expect(marshall(input)).toEqual(mockOutput);
-    expect(convertToAttr).toHaveBeenCalledTimes(1);
-    expect(convertToAttr).toHaveBeenCalledWith(input, undefined);
+    expect(marshall(input)).toEqual({
+      a: { S: "A" },
+      b: { S: "B" },
+    });
+  });
+
+  it("should resolve signatures correctly", () => {
+    const ss: AttributeValue.SSMember = marshall(new Set(["a"]));
+    expect(ss).toEqual({
+      SS: ["a"],
+    } as AttributeValue.SSMember);
+    const ns: AttributeValue.NSMember = marshall(new Set([0]));
+    expect(ns).toEqual({
+      NS: ["0"],
+    } as AttributeValue.NSMember);
+    const bs: AttributeValue.BSMember = marshall(new Set([new Uint8Array(4)]));
+    expect(bs).toEqual({
+      BS: [new Uint8Array(4)],
+    } as AttributeValue.BSMember);
+    const s: AttributeValue.SMember = marshall("a");
+    expect(s).toEqual({
+      S: "a",
+    } as AttributeValue.SMember);
+    const n1: AttributeValue.NMember = marshall(0);
+    expect(n1).toEqual({ N: "0" } as AttributeValue.NMember);
+    const n2: AttributeValue.NMember = marshall(BigInt(0));
+    expect(n2).toEqual({ N: "0" } as AttributeValue.NMember);
+    const n3: AttributeValue.NMember = marshall(NumberValue.from(0));
+    expect(n3).toEqual({ N: "0" } as AttributeValue.NMember);
+    const binary: AttributeValue.BMember = marshall(new Uint8Array(4));
+    expect(binary).toEqual({
+      B: new Uint8Array(4),
+    } as AttributeValue.BMember);
+    const nil: AttributeValue.NULLMember = marshall(null);
+    expect(nil).toEqual({
+      NULL: true,
+    } as AttributeValue.NULLMember);
+    const bool: AttributeValue.BOOLMember = marshall(false as boolean);
+    expect(bool).toEqual({
+      BOOL: false,
+    } as AttributeValue.BOOLMember);
+    const array: AttributeValue[] = marshall([1, 2, 3]);
+    expect(array).toEqual([{ N: "1" }, { N: "2" }, { N: "3" }] as AttributeValue.NMember[]);
+    const arrayLDefault: AttributeValue[] = marshall([1, 2, 3], {});
+    expect(arrayLDefault).toEqual([{ N: "1" }, { N: "2" }, { N: "3" }] as AttributeValue.NMember[]);
+    const arrayLFalse: AttributeValue[] = marshall([1, 2, 3], {
+      convertTopLevelContainer: false,
+    });
+    expect(arrayLFalse).toEqual([{ N: "1" }, { N: "2" }, { N: "3" }] as AttributeValue.NMember[]);
+    const arrayLTrue: AttributeValue.LMember = marshall([1, 2, 3], {
+      convertTopLevelContainer: true,
+    });
+    expect(arrayLTrue).toEqual({
+      L: [{ N: "1" }, { N: "2" }, { N: "3" }],
+    } as AttributeValue.LMember);
+    const arrayLBoolean: AttributeValue.LMember | AttributeValue[] = marshall([1, 2, 3], {
+      convertTopLevelContainer: true as boolean,
+    });
+    expect(arrayLBoolean).toEqual({
+      L: [{ N: "1" }, { N: "2" }, { N: "3" }],
+    } as AttributeValue.LMember);
+    const object1: Record<string, AttributeValue> = marshall({
+      pk: "abc",
+      sk: "xyz",
+    });
+    expect(object1).toEqual({
+      pk: { S: "abc" },
+      sk: { S: "xyz" },
+    } as Record<string, AttributeValue.SMember>);
+    const object2: Record<string, AttributeValue> = marshall(
+      {
+        pk: "abc",
+        sk: "xyz",
+      },
+      {}
+    );
+    expect(object2).toEqual({
+      pk: { S: "abc" },
+      sk: { S: "xyz" },
+    } as Record<string, AttributeValue.SMember>);
+    const object3: AttributeValue.MMember = marshall(
+      {
+        pk: "abc",
+        sk: "xyz",
+      },
+      { convertTopLevelContainer: true }
+    );
+    expect(object3).toEqual({
+      M: {
+        pk: { S: "abc" },
+        sk: { S: "xyz" },
+      },
+    } as AttributeValue.MMember);
+    const object4: Record<string, AttributeValue> | AttributeValue.MMember = marshall(
+      {
+        pk: "abc",
+        sk: "xyz",
+      },
+      { convertTopLevelContainer: true as boolean }
+    );
+    expect(object4).toEqual({
+      M: {
+        pk: { S: "abc" },
+        sk: { S: "xyz" },
+      },
+    } as AttributeValue.MMember);
+    const map: Record<string, AttributeValue> = marshall(new Map([["a", "a"]]));
+    expect(map).toEqual({
+      a: { S: "a" },
+    } as Record<string, AttributeValue.SMember>);
+    const unrecognizedClassInstance: Record<string, AttributeValue> = marshall(new Date(), {
+      convertClassInstanceToMap: true,
+    });
+    expect(unrecognizedClassInstance).toEqual({} as Record<string, AttributeValue>);
+    const unrecognizedClassInstance2: Record<string, AttributeValue> = marshall(
+      new (class {
+        public a = "a";
+        public b = "b";
+      })(),
+      {
+        convertClassInstanceToMap: true,
+      }
+    );
+    expect(unrecognizedClassInstance2).toEqual({
+      a: { S: "a" },
+      b: { S: "b" },
+    } as Record<string, AttributeValue>);
+
+    // this strange cast asserts that untyped fallback results in the `any` type.
+    const untyped: Symbol = marshall(null as any) as Symbol;
+    expect(untyped).toEqual({
+      NULL: true,
+    });
+
+    const empty: Record<string, AttributeValue> = marshall({} as {});
+    expect(empty).toEqual({} as Record<string, AttributeValue>);
+
+    const empty2: AttributeValue.MMember = marshall({} as {}, { convertTopLevelContainer: true });
+    expect(empty2).toEqual({ M: {} } as AttributeValue.MMember);
   });
 
   it("with class instance as an input", () => {
@@ -58,8 +190,9 @@ describe("marshall", () => {
     }
     const input = new TestInputClass("A", "B");
 
-    expect(marshall(input)).toEqual(mockOutput);
-    expect(convertToAttr).toHaveBeenCalledTimes(1);
-    expect(convertToAttr).toHaveBeenCalledWith(input, undefined);
+    expect(marshall(input, { convertClassInstanceToMap: true })).toEqual({
+      a: { S: "A" },
+      b: { S: "B" },
+    });
   });
 });
diff --git a/packages/util-dynamodb/src/marshall.ts b/packages/util-dynamodb/src/marshall.ts
index 717838d564d2..2fefc0f679d9 100644
--- a/packages/util-dynamodb/src/marshall.ts
+++ b/packages/util-dynamodb/src/marshall.ts
@@ -2,6 +2,7 @@ import { AttributeValue } from "@aws-sdk/client-dynamodb";
 
 import { convertToAttr } from "./convertToAttr";
 import { NativeAttributeBinary, NativeAttributeValue } from "./models";
+import { NumberValue } from "./NumberValue";
 
 /**
  * An optional configuration object for `marshall`
@@ -36,19 +37,51 @@ export interface marshallOptions {
  * @param options - An optional configuration object for `marshall`
  *
  */
+export function marshall(data: null, options?: marshallOptions): AttributeValue.NULLMember;
+export function marshall(
+  data: Set<bigint> | Set<number> | Set<NumberValue>,
+  options?: marshallOptions
+): AttributeValue.NSMember;
 export function marshall(data: Set<string>, options?: marshallOptions): AttributeValue.SSMember;
-export function marshall(data: Set<number>, options?: marshallOptions): AttributeValue.NSMember;
 export function marshall(data: Set<NativeAttributeBinary>, options?: marshallOptions): AttributeValue.BSMember;
-export function marshall<M extends { [K in keyof M]: NativeAttributeValue }>(
-  data: M,
-  options?: marshallOptions
-): Record<string, AttributeValue>;
-export function marshall<L extends NativeAttributeValue[]>(data: L, options?: marshallOptions): AttributeValue[];
-export function marshall(data: string, options?: marshallOptions): AttributeValue.SMember;
-export function marshall(data: number, options?: marshallOptions): AttributeValue.NMember;
 export function marshall(data: NativeAttributeBinary, options?: marshallOptions): AttributeValue.BMember;
-export function marshall(data: null, options?: marshallOptions): AttributeValue.NULLMember;
 export function marshall(data: boolean, options?: marshallOptions): AttributeValue.BOOLMember;
+export function marshall(data: number | NumberValue | bigint, options?: marshallOptions): AttributeValue.NMember;
+export function marshall(data: string, options?: marshallOptions): AttributeValue.SMember;
+export function marshall(data: boolean, options?: marshallOptions): AttributeValue.BOOLMember;
+export function marshall<O extends { convertTopLevelContainer: true }>(
+  data: NativeAttributeValue[],
+  options: marshallOptions & O
+): AttributeValue.LMember;
+export function marshall<O extends { convertTopLevelContainer: false }>(
+  data: NativeAttributeValue[],
+  options: marshallOptions & O
+): AttributeValue[];
+export function marshall<O extends { convertTopLevelContainer: boolean }>(
+  data: NativeAttributeValue[],
+  options: marshallOptions & O
+): AttributeValue[] | AttributeValue.LMember;
+export function marshall(data: NativeAttributeValue[], options?: marshallOptions): AttributeValue[];
+export function marshall<O extends { convertTopLevelContainer: true }>(
+  data: Map<string, NativeAttributeValue> | Record<string, NativeAttributeValue>,
+  options: marshallOptions & O
+): AttributeValue.MMember;
+export function marshall<O extends { convertTopLevelContainer: false }>(
+  data: Map<string, NativeAttributeValue> | Record<string, NativeAttributeValue>,
+  options: marshallOptions & O
+): Record<string, AttributeValue>;
+export function marshall<O extends { convertTopLevelContainer: boolean }>(
+  data: Map<string, NativeAttributeValue> | Record<string, NativeAttributeValue>,
+  options: marshallOptions & O
+): Record<string, AttributeValue> | AttributeValue.MMember;
+export function marshall(
+  data: Map<string, NativeAttributeValue> | Record<string, NativeAttributeValue>,
+  options?: marshallOptions
+): Record<string, AttributeValue>;
+export function marshall(data: any, options?: marshallOptions): any;
+/**
+ * This signature will be unmatchable but is included for information.
+ */
 export function marshall(data: unknown, options?: marshallOptions): AttributeValue.$UnknownMember;
 export function marshall(data: unknown, options?: marshallOptions) {
   const attributeValue: AttributeValue = convertToAttr(data, options);
diff --git a/packages/util-dynamodb/src/models.ts b/packages/util-dynamodb/src/models.ts
index 8068add9a43d..b61953da7fc2 100644
--- a/packages/util-dynamodb/src/models.ts
+++ b/packages/util-dynamodb/src/models.ts
@@ -1,3 +1,5 @@
+import type { Exact } from "@smithy/types";
+
 /**
  * A interface recognizable as a numeric value that stores the underlying number
  * as a string.
@@ -10,6 +12,9 @@ export interface NumberValue {
   readonly value: string;
 }
 
+/**
+ * @public
+ */
 export type NativeAttributeValue =
   | NativeScalarAttributeValue
   | { [key: string]: NativeAttributeValue }
@@ -17,6 +22,9 @@ export type NativeAttributeValue =
   | Set<number | bigint | NumberValue | string | NativeAttributeBinary | undefined>
   | InstanceType<{ new (...args: any[]): any }>; // accepts any class instance with options.convertClassInstanceToMap
 
+/**
+ * @public
+ */
 export type NativeScalarAttributeValue =
   | null
   | undefined
@@ -36,9 +44,16 @@ declare global {
   interface File {}
 }
 
+type Unavailable = never;
+type BlobDefined = Exact<Blob, {}> extends true ? false : true;
+type BlobOptionalType = BlobDefined extends true ? Blob : Unavailable;
+
+/**
+ * @public
+ */
 export type NativeAttributeBinary =
   | ArrayBuffer
-  | Blob
+  | BlobOptionalType
   | Buffer
   | DataView
   | File