diff --git a/src/codes/code_funcs.py b/src/codes/code_funcs.py
index c8a4a10..a64b34d 100644
--- a/src/codes/code_funcs.py
+++ b/src/codes/code_funcs.py
@@ -390,7 +390,11 @@ def code_implicit_rag(service, implicit_run_dict, filename, constants):
                 if matching_codes:
                     # Split pipe-delimited codes into individual codes
                     for code in matching_codes:
-                        proc_codes.extend(code)
+                        # Handle pipe-delimited codes (e.g., "99170-99199|99200-99210")
+                        if "|" in code:
+                            proc_codes.extend(code.split("|"))
+                        else:
+                            proc_codes.append(code)
                     proc_descs.append(description)
             if description in hcpcs_mapping.values():
                 matching_codes = [
@@ -399,7 +403,11 @@ def code_implicit_rag(service, implicit_run_dict, filename, constants):
                 if matching_codes:
                     # Split pipe-delimited codes into individual codes
                     for code in matching_codes:
-                        proc_codes.extend(code)
+                        # Handle pipe-delimited codes (e.g., "99170-99199|99200-99210")
+                        if "|" in code:
+                            proc_codes.extend(code.split("|"))
+                        else:
+                            proc_codes.append(code)
                     proc_descs.append(description)
             if description in rev_mapping.values():
                 matching_codes = [
@@ -408,7 +416,11 @@ def code_implicit_rag(service, implicit_run_dict, filename, constants):
                 if matching_codes:
                     # Split pipe-delimited codes into individual codes
                     for code in matching_codes:
-                        rev_codes.extend(code)
+                        # Handle pipe-delimited codes (e.g., "99170-99199|99200-99210")
+                        if "|" in code:
+                            rev_codes.extend(code.split("|"))
+                        else:
+                            rev_codes.append(code)
                     rev_descs.append(description)
 
         # Combine answers
diff --git a/src/pipelines/clients/bcbs_promise/file_processing.py b/src/pipelines/clients/bcbs_promise/file_processing.py
index a962ae5..d3c3c8c 100644
--- a/src/pipelines/clients/bcbs_promise/file_processing.py
+++ b/src/pipelines/clients/bcbs_promise/file_processing.py
@@ -260,6 +260,14 @@ def run_one_to_one_prompts(
         one_to_one_results, contract_text
     )
 
+    ################## Normalize before crosswalk ##################
+    # Normalize before get_crosswalk_fields (which expects/returns a list)
+    # get_crosswalk_fields and fill_na_mapping are mechanical steps (no LLM),
+    # so they won't introduce single-element lists that need normalization
+    one_to_one_results = string_utils.normalize_one_to_one_answers_dict(
+        one_to_one_results
+    )
+
     ################## Crosswalk Fields ##################
     one_to_one_results = aarete_derived.get_crosswalk_fields(
         [one_to_one_results], constants
diff --git a/src/pipelines/clients/bcbs_promise/prompts/prompt_calls.py b/src/pipelines/clients/bcbs_promise/prompts/prompt_calls.py
index 1357402..35c1dde 100644
--- a/src/pipelines/clients/bcbs_promise/prompts/prompt_calls.py
+++ b/src/pipelines/clients/bcbs_promise/prompts/prompt_calls.py
@@ -31,6 +31,13 @@ def prompt_exhibit_level(
 
     llm_answer_final = _parser(llm_answer_raw)
 
+    # Normalize CLAIM_TYPE_CD if present: convert single-element lists to strings
+    # This field should be a single value even though it's a 1:N field
+    if "CLAIM_TYPE_CD" in llm_answer_final:
+        llm_answer_final["CLAIM_TYPE_CD"] = string_utils.normalize_one_to_one_field_value(
+            "CLAIM_TYPE_CD", llm_answer_final["CLAIM_TYPE_CD"]
+        )
+
     return llm_answer_final
 
 
@@ -437,6 +444,11 @@ def prompt_full_context(
             instruction=prompt_templates.ONE_TO_ONE_MULTI_FIELD_INSTRUCTION(),
         )
         full_context_answers_dict = _parser(claude_answer_raw)
+        # Normalize 1:1 fields: convert single-element lists to strings
+        # Preserves legitimate multi-value lists (e.g., LOB, PROGRAM when passed to 1:1)
+        full_context_answers_dict = string_utils.normalize_one_to_one_answers_dict(
+            full_context_answers_dict
+        )
     except Exception as e:
         logging.error(f"Error processing high accuracy fields: {str(e)}")
         full_context_answers_dict = {}
diff --git a/src/pipelines/clients/clover/file_processing.py b/src/pipelines/clients/clover/file_processing.py
index f441d10..b9e3886 100644
--- a/src/pipelines/clients/clover/file_processing.py
+++ b/src/pipelines/clients/clover/file_processing.py
@@ -262,6 +262,14 @@ def run_one_to_one_prompts(
         one_to_one_results, contract_text
     )
 
+    ################## Normalize before crosswalk ##################
+    # Normalize before get_crosswalk_fields (which expects/returns a list)
+    # get_crosswalk_fields and fill_na_mapping are mechanical steps (no LLM),
+    # so they won't introduce single-element lists that need normalization
+    one_to_one_results = string_utils.normalize_one_to_one_answers_dict(
+        one_to_one_results
+    )
+
     ################## Crosswalk Fields ##################
     one_to_one_results = aarete_derived.get_crosswalk_fields(
         [one_to_one_results], constants
diff --git a/src/pipelines/clients/clover/prompts/prompt_calls.py b/src/pipelines/clients/clover/prompts/prompt_calls.py
index 01a0e44..80c45a2 100644
--- a/src/pipelines/clients/clover/prompts/prompt_calls.py
+++ b/src/pipelines/clients/clover/prompts/prompt_calls.py
@@ -37,6 +37,13 @@ def prompt_exhibit_level(
 
     llm_answer_final = _parser(llm_answer_raw)
 
+    # Normalize CLAIM_TYPE_CD if present: convert single-element lists to strings
+    # This field should be a single value even though it's a 1:N field
+    if "CLAIM_TYPE_CD" in llm_answer_final:
+        llm_answer_final["CLAIM_TYPE_CD"] = string_utils.normalize_one_to_one_field_value(
+            "CLAIM_TYPE_CD", llm_answer_final["CLAIM_TYPE_CD"]
+        )
+
     return llm_answer_final
 
 
@@ -463,6 +470,12 @@ def prompt_full_context(
         if not isinstance(full_context_answers_dict, dict):
             full_context_answers_dict = extract_and_parse(claude_answer_raw)
 
+        # Normalize 1:1 fields: convert single-element lists to strings
+        # Preserves legitimate multi-value lists (e.g., LOB, PROGRAM when passed to 1:1)
+        full_context_answers_dict = string_utils.normalize_one_to_one_answers_dict(
+            full_context_answers_dict
+        )
+
     except Exception as e:
         logging.error(f"Error processing high accuracy fields: {str(e)}")
         full_context_answers_dict = {}
diff --git a/src/pipelines/saas/file_processing.py b/src/pipelines/saas/file_processing.py
index 9cab5ef..2ed83aa 100644
--- a/src/pipelines/saas/file_processing.py
+++ b/src/pipelines/saas/file_processing.py
@@ -242,6 +242,14 @@ def run_one_to_one_prompts(
         one_to_one_results, contract_text
     )
 
+    ################## Normalize before crosswalk ##################
+    # Normalize before get_crosswalk_fields (which expects/returns a list)
+    # get_crosswalk_fields and fill_na_mapping are mechanical steps (no LLM),
+    # so they won't introduce single-element lists that need normalization
+    one_to_one_results = string_utils.normalize_one_to_one_answers_dict(
+        one_to_one_results
+    )
+
     ################## Crosswalk Fields ##################
     one_to_one_results = aarete_derived.get_crosswalk_fields(
         [one_to_one_results], constants
diff --git a/src/pipelines/saas/prompts/prompt_calls.py b/src/pipelines/saas/prompts/prompt_calls.py
index 5e03d50..51ae68b 100644
--- a/src/pipelines/saas/prompts/prompt_calls.py
+++ b/src/pipelines/saas/prompts/prompt_calls.py
@@ -37,6 +37,21 @@ def prompt_exhibit_level(
 
     llm_answer_final = _parser(llm_answer_raw)
 
+    # Normalize CLAIM_TYPE_CD if present: convert single-element lists to strings
+    # This field should be a single value even though it's a 1:N field
+    if "CLAIM_TYPE_CD" in llm_answer_final:
+        original_value = llm_answer_final["CLAIM_TYPE_CD"]
+        print(
+            f"CLAIM_TYPE_CD before normalization: {original_value} (type: {type(original_value)})"
+        )
+        normalized_value = string_utils.normalize_one_to_one_field_value(
+            "CLAIM_TYPE_CD", original_value
+        )
+        print(
+            f"CLAIM_TYPE_CD after normalization: {normalized_value} (type: {type(normalized_value)})"
+        )
+        llm_answer_final["CLAIM_TYPE_CD"] = normalized_value
+
     return llm_answer_final
 
 
@@ -294,7 +309,7 @@ def prompt_lob_relationship(
     """
     programs = answer_dict.get(field)
     dynamic_primary_values = (
-        f"LOB: {answer_dict.get("AARETE_DERIVED_LOB")}\nPROGRAM: {programs}"
+        f"LOB: {answer_dict.get('AARETE_DERIVED_LOB')}\nPROGRAM: {programs}"
     )
 
     prompt, _parser = prompt_templates.LOB_RELATIONSHIP(
@@ -393,6 +408,11 @@ def prompt_full_context(
         )
 
         full_context_answers_dict = _parser(claude_answer_raw)
+        # Normalize 1:1 fields: convert single-element lists to strings
+        # Preserves legitimate multi-value lists (e.g., LOB, PROGRAM when passed to 1:1)
+        full_context_answers_dict = string_utils.normalize_one_to_one_answers_dict(
+            full_context_answers_dict
+        )
     except Exception as e:
         logging.error(f"Error processing high accuracy fields: {str(e)}")
         full_context_answers_dict = {}
diff --git a/src/pipelines/shared/extraction/one_to_one_funcs.py b/src/pipelines/shared/extraction/one_to_one_funcs.py
index cc423ab..0b0318c 100644
--- a/src/pipelines/shared/extraction/one_to_one_funcs.py
+++ b/src/pipelines/shared/extraction/one_to_one_funcs.py
@@ -235,6 +235,12 @@ def run_full_context_fields(
     # Run Special Case Breakout on any breakout terms
     full_context_answers_dict = one_to_one_breakout(full_context_answers_dict, filename)
 
+    # Normalize breakout fields: prompt_special_case_breakout uses _json_dict_parser
+    # which may return lists, so normalize any newly added fields
+    full_context_answers_dict = string_utils.normalize_one_to_one_answers_dict(
+        full_context_answers_dict
+    )
+
     # Handle separate one-to-one fields that require individual processing
     separate_fields = one_to_one_fields.filter(field_type="full_context_separate")
 
@@ -323,6 +329,13 @@ def one_to_one_breakout(
             breakout_answer_dict = prompt_calls.prompt_special_case_breakout(
                 breakout_template, term_answer, filename
             )
+            # Normalize breakout fields for 1:1: _json_dict_parser may return lists for values
+            # Convert single-element lists to strings, preserve multi-value lists
+            # Note: This normalization is only for 1:1 fields; 1:N breakouts are handled separately
+            if isinstance(breakout_answer_dict, dict):
+                breakout_answer_dict = string_utils.normalize_one_to_one_answers_dict(
+                    breakout_answer_dict
+                )
             full_context_answers_dict.update(breakout_answer_dict)
     return full_context_answers_dict
 
diff --git a/src/pipelines/shared/extraction/tin_npi_funcs.py b/src/pipelines/shared/extraction/tin_npi_funcs.py
index 132720e..8d63b47 100644
--- a/src/pipelines/shared/extraction/tin_npi_funcs.py
+++ b/src/pipelines/shared/extraction/tin_npi_funcs.py
@@ -228,7 +228,13 @@ def merge_provider_info_with_hybrid_smart_chunking(one_to_one_results, filename)
     other_npis = []
     other_names = []
 
-    provider_name = one_to_one_results.get("PROVIDER_NAME")  # Returns List
+    provider_name = one_to_one_results.get("PROVIDER_NAME")  # Can be List or string
+    # Normalize provider_name to list: if string, convert to list to avoid character splitting
+    if isinstance(provider_name, str):
+        provider_name = [provider_name]
+    elif not isinstance(provider_name, list):
+        provider_name = []
+    
     provider_info = one_to_one_results[
         "PROV_INFO_JSON"
     ]  # Returns string representation of list
@@ -243,6 +249,21 @@ def merge_provider_info_with_hybrid_smart_chunking(one_to_one_results, filename)
         tins = provider.get("TIN") or []
         npis = provider.get("NPI") or []
         names = provider.get("NAME") or []
+        
+        # Normalize to lists: if string, convert to list to avoid character splitting
+        if isinstance(tins, str):
+            tins = [tins]
+        elif not isinstance(tins, list):
+            tins = []
+        if isinstance(npis, str):
+            npis = [npis]
+        elif not isinstance(npis, list):
+            npis = []
+        if isinstance(names, str):
+            names = [names]
+        elif not isinstance(names, list):
+            names = []
+        
         name_matches = prompt_calls.provider_name_match_check(
             names, provider_name, filename
         )  # Returns Boolean
diff --git a/src/pipelines/shared/postprocessing/aarete_derived.py b/src/pipelines/shared/postprocessing/aarete_derived.py
index a4daea3..8cda91d 100644
--- a/src/pipelines/shared/postprocessing/aarete_derived.py
+++ b/src/pipelines/shared/postprocessing/aarete_derived.py
@@ -169,6 +169,19 @@ def fill_na_mapping(answer_dicts):
 
 
 def get_crosswalk_fields(answer_dicts: list, constants: Constants):
+    """
+    Apply crosswalk mappings to derive target fields from source fields.
+
+    Fields that should be single values (strings) even when crosswalk creates lists:
+    - AARETE_DERIVED_CLAIM_TYPE_CD: Claim type is a single classification value
+    - Other AARETE_DERIVED_* fields that represent single classifications (not multi-value like LOB)
+    """
+    # Fields that should always be single values (strings), not lists
+    # These are typically classification/derived fields that represent a single value
+    SINGLE_VALUE_FIELDS = {
+        "AARETE_DERIVED_CLAIM_TYPE_CD",
+        # Add other single-value derived fields here as needed
+    }
 
     crosswalk_fields = FieldSet(file_path=config.FIELD_JSON_PATH, crosswalk=True)
     for to_field in crosswalk_fields.fields:
@@ -219,7 +232,13 @@ def get_crosswalk_fields(answer_dicts: list, constants: Constants):
                                     to_field_answer_list.append(
                                         individual_from_field_value
                                     )
-                    answer_dict[to_field_name] = to_field_answer_list
+                    
+                    # Assign the result: convert to string if it's a single-value field with one element
+                    if to_field_name in SINGLE_VALUE_FIELDS and len(to_field_answer_list) == 1:
+                        answer_dict[to_field_name] = to_field_answer_list[0]
+                    else:
+                        answer_dict[to_field_name] = to_field_answer_list
+                    
                     # update from field value to list if not already
                     if not isinstance(from_field_value, list):
                         answer_dict[from_field_name] = from_field_value_list
diff --git a/src/pipelines/shared/preprocessing/hybrid_smart_chunking_funcs.py b/src/pipelines/shared/preprocessing/hybrid_smart_chunking_funcs.py
index 5942305..95a5fd4 100644
--- a/src/pipelines/shared/preprocessing/hybrid_smart_chunking_funcs.py
+++ b/src/pipelines/shared/preprocessing/hybrid_smart_chunking_funcs.py
@@ -283,6 +283,11 @@ def run_hybrid_smart_chunked_fields(
         answers_dict = string_utils.normalize_state_field(
             answers_dict, field_name="PAYER_STATE"
         )
+
+        # Normalize all 1:1 fields: convert single-element lists to strings
+        # Preserves legitimate multi-value lists (e.g., LOB, PROGRAM when passed to 1:1)
+        answers_dict = string_utils.normalize_one_to_one_answers_dict(answers_dict)
+
         return answers_dict
 
     except Exception as e:
diff --git a/src/utils/string_utils.py b/src/utils/string_utils.py
index 8515815..6fc5f97 100644
--- a/src/utils/string_utils.py
+++ b/src/utils/string_utils.py
@@ -806,3 +806,94 @@ def normalize_to_json_list(val):
         result = json.dumps(expanded)
         return result
     return val
+
+
+def normalize_one_to_one_field_value(field_name: str, value) -> str | list:
+    """
+    Normalize a 1:1 field value to ensure single-value fields are strings, not lists.
+
+    This function handles the common case where LLM returns a single-value field as
+    a list with one element (e.g., ['The Value']). It extracts the string from such
+    lists while preserving legitimate multi-value lists.
+
+    Args:
+        field_name (str): Name of the field being normalized (for logging/debugging)
+        value: The field value to normalize. Can be:
+            - str: Returned as-is
+            - list with 1 element: Extract the string
+            - list with >1 elements: Returned unchanged (may be legitimate multi-value)
+            - None/empty: Returned as-is
+
+    Returns:
+        str | list: Normalized value:
+            - If input is a list with exactly 1 element: returns that element as string
+            - If input is already a string: returns as-is
+            - If input is a list with >1 elements: returns list unchanged
+            - If input is None or empty: returns as-is
+
+    Examples:
+        >>> normalize_one_to_one_field_value("CONTRACT_TITLE", ["Provider Agreement"])
+        'Provider Agreement'
+        >>> normalize_one_to_one_field_value("PAYER_NAME", "Aetna")
+        'Aetna'
+        >>> normalize_one_to_one_field_value("PROVIDER_NAME", ["Provider A", "Provider B"])
+        ['Provider A', 'Provider B']  # Multi-value preserved
+        >>> normalize_one_to_one_field_value("LOB", ["Medicare", "Medicaid"])
+        ['Medicare', 'Medicaid']  # Multi-value preserved
+    """
+    # Handle None and empty values
+    if value is None or (isinstance(value, str) and is_empty(value)):
+        return value
+
+    # If it's already a string, return as-is
+    if isinstance(value, str):
+        return value
+
+    # If it's a list
+    if isinstance(value, list):
+        # List with exactly 1 element: extract the string
+        if len(value) == 1:
+            return str(value[0]) if value[0] is not None else "N/A"
+        # List with >1 elements: preserve (may be legitimate multi-value)
+        # This handles cases like PROVIDER_NAME with multiple providers,
+        # or dynamic fields (LOB, PROGRAM, PRODUCT, NETWORK) when passed to 1:1
+        elif len(value) > 1:
+            return value
+        # Empty list: return "N/A"
+        else:
+            return "N/A"
+
+    # For any other type, convert to string
+    return str(value) if value is not None else "N/A"
+
+
+def normalize_one_to_one_answers_dict(answers_dict: dict[str, str | list]) -> dict[str, str | list]:
+    """
+    Normalize all values in a 1:1 answers dictionary.
+
+    Applies normalization to all fields in the dictionary, converting single-element
+    lists to strings while preserving legitimate multi-value lists.
+
+    Args:
+        answers_dict (dict): Dictionary of field names to values (may be strings or lists)
+
+    Returns:
+        dict: Dictionary with normalized values (single-element lists converted to strings)
+
+    Example:
+        >>> answers = {
+        ...     "CONTRACT_TITLE": ["Provider Agreement"],
+        ...     "PAYER_NAME": "Aetna",
+        ...     "PROVIDER_NAME": ["Provider A", "Provider B"]
+        ... }
+        >>> normalize_one_to_one_answers_dict(answers)
+        {
+            "CONTRACT_TITLE": "Provider Agreement",
+            "PAYER_NAME": "Aetna",
+            "PROVIDER_NAME": ["Provider A", "Provider B"]
+        }
+    """
+    normalized = {}
+    for field_name, value in answers_dict.items():
+        normalized[field_name] = normalize_one_to_one_field_value(field_name, value)
+    return normalized