diff --git a/api/openapi-spec/swagger.json b/api/openapi-spec/swagger.json
index 4d379ef298a..c66df3721d2 100644
--- a/api/openapi-spec/swagger.json
+++ b/api/openapi-spec/swagger.json
@@ -16709,7 +16709,8 @@
           "type": "array"
         },
         "default": {
-          "$ref": "#/definitions/io.k8s.apiextensions-apiserver.pkg.apis.apiextensions.v1beta1.JSON"
+          "$ref": "#/definitions/io.k8s.apiextensions-apiserver.pkg.apis.apiextensions.v1beta1.JSON",
+          "description": "default is a default value for undefined object fields. Defaulting is an alpha feature under the CustomResourceDefaulting feature gate. Defaulting requires spec.preserveUnknownFields to be false."
         },
         "definitions": {
           "additionalProperties": {
diff --git a/staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1/generated.proto b/staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1/generated.proto
index ec030190e6e..9308988f70e 100644
--- a/staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1/generated.proto
+++ b/staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1/generated.proto
@@ -394,6 +394,9 @@ message JSONSchemaProps {
 
   optional string title = 7;
 
+  // default is a default value for undefined object fields.
+  // Defaulting is an alpha feature under the CustomResourceDefaulting feature gate.
+  // Defaulting requires spec.preserveUnknownFields to be false.
   optional JSON default = 8;
 
   optional double maximum = 9;
diff --git a/staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/validation/BUILD b/staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/validation/BUILD
index 1cb403092cb..27d96a3177b 100644
--- a/staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/validation/BUILD
+++ b/staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/validation/BUILD
@@ -15,15 +15,19 @@ go_library(
         "//staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions:go_default_library",
         "//staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1:go_default_library",
         "//staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema:go_default_library",
+        "//staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema/pruning:go_default_library",
         "//staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/validation:go_default_library",
         "//staging/src/k8s.io/apiextensions-apiserver/pkg/features:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/api/equality:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/api/validation:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/runtime:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/util/sets:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/util/validation:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/util/validation/field:go_default_library",
         "//staging/src/k8s.io/apiserver/pkg/util/feature:go_default_library",
         "//staging/src/k8s.io/apiserver/pkg/util/webhook:go_default_library",
+        "//vendor/github.com/go-openapi/strfmt:go_default_library",
+        "//vendor/github.com/go-openapi/validate:go_default_library",
     ],
 )
 
@@ -33,8 +37,18 @@ go_test(
     embed = [":go_default_library"],
     deps = [
         "//staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions:go_default_library",
+        "//staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/fuzzer:go_default_library",
+        "//staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1:go_default_library",
+        "//staging/src/k8s.io/apiextensions-apiserver/pkg/features:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/api/apitesting/fuzzer:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/runtime:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/runtime/serializer:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/util/json:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/util/validation/field:go_default_library",
+        "//staging/src/k8s.io/apiserver/pkg/util/feature:go_default_library",
+        "//staging/src/k8s.io/component-base/featuregate:go_default_library",
+        "//staging/src/k8s.io/component-base/featuregate/testing:go_default_library",
         "//vendor/k8s.io/utils/pointer:go_default_library",
     ],
 )
diff --git a/staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/BUILD b/staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/BUILD
index 1c2dd779f40..dbd44f4f64b 100644
--- a/staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/BUILD
+++ b/staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/BUILD
@@ -24,6 +24,7 @@ go_library(
         "//staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1:go_default_library",
         "//staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/conversion:go_default_library",
         "//staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema:go_default_library",
+        "//staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema/defaulting:go_default_library",
         "//staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema/pruning:go_default_library",
         "//staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/validation:go_default_library",
         "//staging/src/k8s.io/apiextensions-apiserver/pkg/client/clientset/clientset:go_default_library",
diff --git a/staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema/BUILD b/staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema/BUILD
index 6717f67507f..1ff62e23a24 100644
--- a/staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema/BUILD
+++ b/staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema/BUILD
@@ -34,6 +34,7 @@ filegroup(
     name = "all-srcs",
     srcs = [
         ":package-srcs",
+        "//staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema/defaulting:all-srcs",
         "//staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema/pruning:all-srcs",
     ],
     tags = ["automanaged"],
diff --git a/staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema/defaulting/BUILD b/staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema/defaulting/BUILD
new file mode 100644
index 00000000000..b2168fca3a8
--- /dev/null
+++ b/staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema/defaulting/BUILD
@@ -0,0 +1,37 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["algorithm.go"],
+    importmap = "k8s.io/kubernetes/vendor/k8s.io/apiextensions-apiserver/pkg/apiserver/schema/defaulting",
+    importpath = "k8s.io/apiextensions-apiserver/pkg/apiserver/schema/defaulting",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/runtime:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["algorithm_test.go"],
+    embed = [":go_default_library"],
+    deps = [
+        "//staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/util/json:go_default_library",
+    ],
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [":package-srcs"],
+    tags = ["automanaged"],
+    visibility = ["//visibility:public"],
+)
diff --git a/staging/src/k8s.io/apiextensions-apiserver/test/integration/BUILD b/staging/src/k8s.io/apiextensions-apiserver/test/integration/BUILD
index 252307c8e06..20bcfa4cb76 100644
--- a/staging/src/k8s.io/apiextensions-apiserver/test/integration/BUILD
+++ b/staging/src/k8s.io/apiextensions-apiserver/test/integration/BUILD
@@ -12,6 +12,7 @@ go_test(
         "apply_test.go",
         "basic_test.go",
         "change_test.go",
+        "defaulting_test.go",
         "finalization_test.go",
         "objectmeta_test.go",
         "pruning_test.go",
diff --git a/vendor/modules.txt b/vendor/modules.txt
index 2fd3db5a816..ee910ce07f3 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -1073,6 +1073,7 @@ k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/validation
 k8s.io/apiextensions-apiserver/pkg/apiserver
 k8s.io/apiextensions-apiserver/pkg/apiserver/conversion
 k8s.io/apiextensions-apiserver/pkg/apiserver/schema
+k8s.io/apiextensions-apiserver/pkg/apiserver/schema/defaulting
 k8s.io/apiextensions-apiserver/pkg/apiserver/schema/pruning
 k8s.io/apiextensions-apiserver/pkg/apiserver/validation
 k8s.io/apiextensions-apiserver/pkg/client/clientset/clientset