diff --git a/contrib/experimental/great_expectations_experimental/expectations/expect_column_values_to_have_valid_icd10_code_format.py b/contrib/experimental/great_expectations_experimental/expectations/expect_column_values_to_have_valid_icd10_code_format.py
new file mode 100644
index 000000000000..99332a7456a3
--- /dev/null
+++ b/contrib/experimental/great_expectations_experimental/expectations/expect_column_values_to_have_valid_icd10_code_format.py
@@ -0,0 +1,56 @@
+from great_expectations.expectations.regex_based_column_map_expectation import (
+    RegexBasedColumnMapExpectation,
+)
+
+
+class ExpectColumnValuesToHaveValidICD10CodeFormat(RegexBasedColumnMapExpectation):
+    """Checks if each value matches a regex for ICD10 codes. Does NOT ensure
+    the given code actually exists in any version of the ICD10.
+    """
+
+    regex_camel_name = "ICD10Codes"
+    regex = "[A-Za-z][0-9][A-Za-z0-9](?:\\.[A-Za-z0-9]{0,4})?\\Z"
+    semantic_type_name_plural = None
+
+    examples = [
+        {
+            "data": {
+                "valid_icd10": ["Z99.0", "Z08", "J09.X2", "S22.000A"],
+                "invalid_icd10": ["XXX.X", "AA2.01", "2A", "S22.0000A"],
+            },
+            "tests": [
+                {
+                    "title": "positive_test",
+                    "exact_match_out": False,
+                    "in": {"column": "valid_icd10"},
+                    "out": {"success": True},
+                    "include_in_gallery": True,
+                },
+                {
+                    "title": "negative_test",
+                    "exact_match_out": False,
+                    "in": {"column": "invalid_icd10"},
+                    "out": {"success": False, "unexpected_index_list": [0, 1, 2, 3]},
+                },
+            ],
+            "test_backends": [{"backend": "pandas", "dialects": None}],
+        }
+    ]
+
+    # Here your regex is used to create a custom metric for this expectation
+    map_metric = RegexBasedColumnMapExpectation.register_metric(
+        regex_camel_name=regex_camel_name,
+        regex_=regex,
+    )
+
+    # This object contains metadata for display in the public Gallery
+    library_metadata = {
+        "tags": ["typed-entities", "hackathon"],
+        "contributors": [
+            "@zachlindsey",
+        ],
+    }
+
+
+if __name__ == "__main__":
+    ExpectColumnValuesToHaveValidICD10CodeFormat().print_diagnostic_checklist()