diff --git a/src/registrar/management/commands/load_transition_domain.py b/src/registrar/management/commands/load_transition_domain.py
index 9496789f1..7edf22457 100644
--- a/src/registrar/management/commands/load_transition_domain.py
+++ b/src/registrar/management/commands/load_transition_domain.py
@@ -1,3 +1,4 @@
+import json
 import sys
 import csv
 import logging
@@ -41,7 +42,7 @@ class Command(BaseCommand):
         for testing purposes, but USE WITH CAUTION
         """
         parser.add_argument(
-            "migration_Json_filename",
+            "migration_json_filename",
             help=(
                 "A JSON file that holds the location and filenames"
                 "of all the data files used for migrations"
@@ -319,10 +320,32 @@ class Command(BaseCommand):
 
     def handle(  # noqa: C901
         self,
-        migration_Json_filename,
+        migration_json_filename,
         **options,
     ):
         """Parse the data files and create TransitionDomains."""
+        ### Process JSON file ###
+        # If a JSON was provided, use its values instead of defaults.
+        # TODO: there is no way to discern user overrides from those arg’s defaults.
+        with open(migration_json_filename, "r") as jsonFile:
+            # load JSON object as a dictionary
+            try:
+                data = json.load(jsonFile)
+                # Create an instance of TransitionDomainArguments
+                args = TransitionDomainArguments()
+                # Iterate over the data from the JSON file
+                for key, value in data.items():
+                    # Check if the key exists in TransitionDomainArguments
+                    if hasattr(args, key):
+                        # If it does, update the options
+                        options[key] = value
+            except Exception as err:
+                logger.error(f"""{TerminalColors.FAIL}There was an error loading the JSON responsible
+                for providing filepaths.
+                {TerminalColors.ENDC}
+                """)
+                raise err
+
         sep = options.get("sep")
 
         # If --resetTable was used, prompt user to confirm
@@ -346,9 +369,9 @@ class Command(BaseCommand):
 
         # Main script filenames
         # TODO: @ZANDER to replace this with new TransitionDomainArgument object
-        domain_contacts_filename = directory+ options.get("domain_contacts_filename")
-        contacts_filename = directory+ options.get("contacts_filename")
-        domain_statuses_filename = directory+ options.get("domain_statuses_filename")
+        domain_contacts_filename = directory + "/" + options.get("domain_contacts_filename")
+        contacts_filename = directory + "/" + options.get("contacts_filename")
+        domain_statuses_filename = directory + "/" + options.get("domain_statuses_filename")
 
         # Agency information
         agency_adhoc_filename = options.get("agency_adhoc_filename")
diff --git a/src/registrar/management/commands/master_domain_migrations.py b/src/registrar/management/commands/master_domain_migrations.py
index 673345b8a..58124157f 100644
--- a/src/registrar/management/commands/master_domain_migrations.py
+++ b/src/registrar/management/commands/master_domain_migrations.py
@@ -99,7 +99,7 @@ class Command(BaseCommand):
         # TODO: make this a mandatory argument (if/when we strip out defaults, it will be mandatory)
         # TODO: use the migration directory arg or force user to type FULL filepath?
         parser.add_argument(
-            "migration_Json_filename",
+            "migration_json_filename",
             help=(
                 "A JSON file that holds the location and filenames"
                 "of all the data files used for migrations"
@@ -281,11 +281,8 @@ class Command(BaseCommand):
     # ======================================================
     def run_load_transition_domain_script(
         self,
-        migration_Json_filename: str,
+        migration_json_filename: str,
         file_location: str,
-        domain_contacts_filename: str,
-        contacts_filename: str,
-        domain_statuses_filename: str,
         sep: str,
         reset_table: bool,
         debug_on: bool,
@@ -297,7 +294,7 @@ class Command(BaseCommand):
         command_script = "load_transition_domain"
         command_string = (
             f"./manage.py {command_script} "
-            f"{file_location+migration_Json_filename}"
+            f"{file_location+migration_json_filename}"
         )
         if sep is not None and sep != "|":
             command_string += f"--sep {sep} "
@@ -321,7 +318,7 @@ class Command(BaseCommand):
         if proceed:
             call_command(
                 command_script,
-                f"{file_location+migration_Json_filename}",
+                f"{file_location+migration_json_filename}",
                 sep=sep,
                 resetTable=reset_table,
                 debug=debug_on,
@@ -368,7 +365,7 @@ class Command(BaseCommand):
 
     def run_migration_scripts(
         self,
-        migration_Json_filename,
+        migration_json_filename,
         file_location,
         domain_contacts_filename,
         contacts_filename,
@@ -420,11 +417,8 @@ class Command(BaseCommand):
 
         # Proceed executing the migration scripts
         self.run_load_transition_domain_script(
-            migration_Json_filename,
+            migration_json_filename,
             file_location,
-            domain_contacts_filename,
-            contacts_filename,
-            domain_statuses_filename,
             sep,
             reset_table,
             debug_on,
@@ -435,7 +429,7 @@ class Command(BaseCommand):
 
     def handle(
         self,
-        migration_Json_filename,
+        migration_json_filename,
         **options,
     ):
         """
@@ -530,7 +524,7 @@ class Command(BaseCommand):
 
             # Run migration scripts
             self.run_migration_scripts(
-                migration_Json_filename,
+                migration_json_filename,
                 file_location,
                 domain_contacts_filename,
                 contacts_filename,
diff --git a/src/registrar/management/commands/utility/transition_domain_arguments.py b/src/registrar/management/commands/utility/transition_domain_arguments.py
index 70f13cfb5..335f74cd9 100644
--- a/src/registrar/management/commands/utility/transition_domain_arguments.py
+++ b/src/registrar/management/commands/utility/transition_domain_arguments.py
@@ -46,6 +46,7 @@ class TransitionDomainArguments:
     domain_additional_filename: Optional[str] = field(default=EnumFilenames.DOMAIN_ADDITIONAL.value[1], repr=True)
     domain_contacts_filename: Optional[str] = field(default=None, repr=True)
     domain_statuses_filename: Optional[str] = field(default=None, repr=True)
+    contacts_filename: Optional[str] = field(default=None, repr=True)
 
     # Flags #
     debug: Optional[bool] = field(default=False, repr=True)