diff --git a/src/constants/investment_columns.py b/src/constants/investment_columns.py
index dc4dffe..f56bf54 100644
--- a/src/constants/investment_columns.py
+++ b/src/constants/investment_columns.py
@@ -6,6 +6,7 @@ COLUMN_ORDER = [
     "FILE_NAME",
     "CONTRACT_TITLE",
     "CONTRACT_AMENDMENT_NUM",
+    "FILENAME_AMENDMENT_NUM",
     "AARETE_DERIVED_AMENDMENT_NUM",
     "CLIENT_NAME",
     "PAYER_NAME",
diff --git a/src/pipelines/shared/preprocessing/hybrid_smart_chunking_funcs.py b/src/pipelines/shared/preprocessing/hybrid_smart_chunking_funcs.py
index 68dac05..df70d25 100644
--- a/src/pipelines/shared/preprocessing/hybrid_smart_chunking_funcs.py
+++ b/src/pipelines/shared/preprocessing/hybrid_smart_chunking_funcs.py
@@ -98,7 +98,6 @@ def process_single_field(
             elif isinstance(val, str):
                 parsed[field.field_name] = val
             field_value = parsed[field.field_name]
-
             if field_value == "N/A":
                 field.field_type = "full_context"
                 if field.field_name == "PAYER_NAME":
@@ -341,6 +340,9 @@ def run_hybrid_smart_chunked_fields(
         gc.collect()
         logging.debug(f"RAG extraction done: {len(answers_dict)} fields")
 
+        # FILENAME_AMENDMENT_NUM
+        answers_dict = extract_amendment_num_from_filename(answers_dict, filename)
+
         answers_dict = check_and_update_effective_date(
             answers_dict, text_dict, filename
         )
@@ -388,3 +390,42 @@ def run_hybrid_smart_chunked_fields(
     except Exception as e:
         logging.error(f"RAG pipeline failed: {e}")
         return {}
+
+
+def extract_amendment_num_from_filename(answer_dict: dict, filename: str) -> dict:
+    """Extract amendment number from filename if not found in contract content.
+
+    Args:
+        answer_dict (dict): Dictionary containing CONTRACT_AMENDMENT_NUM key.
+        filename (str): Filename to extract amendment number from.
+
+    Returns:
+        dict: Updated answer_dict with FILENAME_AMENDMENT_NUM populated.
+    """
+    if (
+        string_utils.is_empty(answer_dict.get("CONTRACT_AMENDMENT_NUM"))
+        or answer_dict.get("CONTRACT_AMENDMENT_NUM") == "UNKNOWN"
+    ):
+
+        prompt = prompt_templates.EXTRACT_AMENDMENT_NUM_FROM_FILENAME(filename)
+        llm_answer_raw = llm_utils.invoke_claude(
+            prompt,
+            "sonnet_latest",
+            filename,
+            cache=True,
+            instruction=prompt_templates.EXTRACT_AMENDMENT_NUM_FROM_FILENAME_INSTRUCTION(),
+            usage_label="EXTRACT_AMENDMENT_NUM_FROM_FILENAME",
+        )
+
+        try:
+            llm_answer_final = string_utils.universal_json_load(llm_answer_raw)
+            answer_dict["FILENAME_AMENDMENT_NUM"] = llm_answer_final.get(
+                "amendment_number", "N/A"
+            )
+        except (ValueError, KeyError) as e:
+            logging.error(
+                f"Failed to parse amendment number from filename {filename}: {e}"
+            )
+            answer_dict["FILENAME_AMENDMENT_NUM"] = "N/A"
+
+    return answer_dict
diff --git a/src/prompts/prompt_templates.py b/src/prompts/prompt_templates.py
index 4ea3b42..7f088c3 100644
--- a/src/prompts/prompt_templates.py
+++ b/src/prompts/prompt_templates.py
@@ -1203,6 +1203,20 @@ def ONE_TO_ONE_MULTI_FIELD_INSTRUCTION() -> str:
     )
 
 
+def EXTRACT_AMENDMENT_NUM_FROM_FILENAME(filename) -> str:
+    return f"""Filename: {filename}"""
+
+
+def EXTRACT_AMENDMENT_NUM_FROM_FILENAME_INSTRUCTION() -> str:
+    return """[OBJECTIVE]\n
+        Analyze the given filename string to extract the amendment number of the contract document if it exists.
+        Return only numeric values representing the amendment number. categorical values like 'A','B' etc are not amednment numbers. If no amendment number is found, return N/A.
+Briefly explain your reasoning, then put your final answer in JSON dictionary format as follows:
+{{
+    "amendment_number": "<extracted amendment number or N/A>"
+}}"""
+
+
 #####################################################################################
 ############################### PREPROCESSING PROMPTS ###############################
 #####################################################################################