diff --git a/.changeset/chilly-ideas-happen.md b/.changeset/chilly-ideas-happen.md
new file mode 100644
index 0000000000000..47355f0a7e3c5
--- /dev/null
+++ b/.changeset/chilly-ideas-happen.md
@@ -0,0 +1,9 @@
+---
+"@fluidframework/merge-tree": minor
+"@fluidframework/sequence": minor
+---
+
+Deprecate getStackContext and associated NestBegin/End
+
+Deprecate SharedSegmentSequence.getStackContext and Client.getStackContext (and the enums ReferenceType.NestBegin and NestEnd they use).
+This functionality is unused, poorly tested, and incurs performance overhead.
diff --git a/api-report/merge-tree.api.md b/api-report/merge-tree.api.md
index b64cf62d08b1f..59d2fb5397e5c 100644
--- a/api-report/merge-tree.api.md
+++ b/api-report/merge-tree.api.md
@@ -145,7 +145,7 @@ export class Client extends TypedEventEmitter<IClientEvents> {
     };
     // (undocumented)
     getShortClientId(longClientId: string): number;
-    // (undocumented)
+    // @deprecated (undocumented)
     getStackContext(startPos: number, rangeLabels: string[]): RangeStackMap;
     // (undocumented)
     insertAtReferencePositionLocal(refPos: ReferencePosition, segment: ISegment): IMergeTreeInsertMsg | undefined;
@@ -953,9 +953,9 @@ export interface ReferencePosition {
 
 // @public
 export enum ReferenceType {
-    // (undocumented)
+    // @deprecated (undocumented)
     NestBegin = 2,
-    // (undocumented)
+    // @deprecated (undocumented)
     NestEnd = 4,
     // (undocumented)
     RangeBegin = 16,
diff --git a/api-report/sequence.api.md b/api-report/sequence.api.md
index eec5f2df83333..5c51582f0a9c2 100644
--- a/api-report/sequence.api.md
+++ b/api-report/sequence.api.md
@@ -547,7 +547,7 @@ export abstract class SharedSegmentSequence<T extends ISegment> extends SharedOb
         posStart: number | undefined;
         posAfterEnd: number | undefined;
     };
-    // (undocumented)
+    // @deprecated (undocumented)
     getStackContext(startPos: number, rangeLabels: string[]): RangeStackMap;
     // @deprecated (undocumented)
     groupOperation(groupOp: IMergeTreeGroupMsg): void;
diff --git a/packages/dds/merge-tree/src/client.ts b/packages/dds/merge-tree/src/client.ts
index e0387b176f17a..18a1ce3392e45 100644
--- a/packages/dds/merge-tree/src/client.ts
+++ b/packages/dds/merge-tree/src/client.ts
@@ -1041,6 +1041,9 @@ export class Client extends TypedEventEmitter<IClientEvents> {
 		return loader.initialize(storage);
 	}
 
+	/**
+	 * @deprecated - this functionality is no longer supported and will be removed
+	 */
 	getStackContext(startPos: number, rangeLabels: string[]): RangeStackMap {
 		return this._mergeTree.getStackContext(
 			startPos,
diff --git a/packages/dds/merge-tree/src/mergeTree.ts b/packages/dds/merge-tree/src/mergeTree.ts
index f40e02964d4bd..321c9fa9b0850 100644
--- a/packages/dds/merge-tree/src/mergeTree.ts
+++ b/packages/dds/merge-tree/src/mergeTree.ts
@@ -1234,6 +1234,9 @@ export class MergeTree {
 		return DetachedReferencePosition;
 	}
 
+	/**
+	 * @deprecated - this functionality is no longer supported and will be removed
+	 */
 	public getStackContext(startPos: number, clientId: number, rangeLabels: string[]) {
 		const searchInfo: IMarkerSearchRangeInfo = {
 			mergeTree: this,
diff --git a/packages/dds/merge-tree/src/ops.ts b/packages/dds/merge-tree/src/ops.ts
index 0a6836a3ccf4f..1ecc9b665a475 100644
--- a/packages/dds/merge-tree/src/ops.ts
+++ b/packages/dds/merge-tree/src/ops.ts
@@ -12,7 +12,13 @@ export enum ReferenceType {
 	 * Allows this reference to be located using the `findTile` API on merge-tree.
 	 */
 	Tile = 0x1,
+	/**
+	 * @deprecated - this functionality is no longer supported and will be removed
+	 */
 	NestBegin = 0x2,
+	/**
+	 * @deprecated - this functionality is no longer supported and will be removed
+	 */
 	NestEnd = 0x4,
 	RangeBegin = 0x10,
 	RangeEnd = 0x20,
diff --git a/packages/dds/sequence/src/sequence.ts b/packages/dds/sequence/src/sequence.ts
index d932fc3d24394..fa03e1a131942 100644
--- a/packages/dds/sequence/src/sequence.ts
+++ b/packages/dds/sequence/src/sequence.ts
@@ -415,6 +415,9 @@ export abstract class SharedSegmentSequence<T extends ISegment>
 		this.client.walkSegments(handler, start, end, accum as TClientData, splitRange);
 	}
 
+	/**
+	 * @deprecated - this functionality is no longer supported and will be removed
+	 */
 	public getStackContext(startPos: number, rangeLabels: string[]): RangeStackMap {
 		return this.client.getStackContext(startPos, rangeLabels);
 	}