diff --git a/pyproject.toml b/pyproject.toml
index de3452c..dd30532 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "folio_data_import"
-version = "0.5.0b5"
+version = "0.5.0"
 description = "A python module to perform bulk import of data into a FOLIO environment. Currently supports MARC and user data import."
 authors = [{ name = "Brooks Travis", email = "brooks.travis@gmail.com" }]
 license = "MIT"
diff --git a/src/folio_data_import/marc_preprocessors/_preprocessors.py b/src/folio_data_import/marc_preprocessors/_preprocessors.py
index 96835da..bb0663f 100644
--- a/src/folio_data_import/marc_preprocessors/_preprocessors.py
+++ b/src/folio_data_import/marc_preprocessors/_preprocessors.py
@@ -508,6 +508,19 @@ def move_authority_subfield_9_to_0_all_controllable_fields(record: Record, **kwa
     return record
 
 
+def mark_deleted(record: Record, **kwargs) -> Record:
+    """
+    Mark the record as deleted by setting the record status to 'd'.
+
+    Args:
+        record (Record): The MARC record to preprocess.
+    Returns:
+        Record: The preprocessed MARC record.
+    """
+    record.leader = pymarc.Leader(record.leader[:5] + "d" + record.leader[6:])
+    return record
+
+
 def ordinal(n: int) -> str:
     s = ("th", "st", "nd", "rd") + ("th",) * 10
     v = n % 100