diff --git a/emanifest-py/src/emanifest/client.py b/emanifest-py/src/emanifest/client.py
index 1f4fd121..4ae3404f 100644
--- a/emanifest-py/src/emanifest/client.py
+++ b/emanifest-py/src/emanifest/client.py
@@ -24,6 +24,7 @@
     CorrectionRevertResponse,
     CorrectionVersionSearchArgs,
     Manifest,
+    ManifestExistsResponse,
     ManifestOperationResponse,
     ManifestSignatureResponse,
     MtnSearchArgs,
@@ -815,13 +816,8 @@ def save_manifest(
             multipart=multipart,
         )
 
-    def check_mtn_exists(self, mtn: str) -> RcrainfoResponse:
-        """
-        Check if Manifest Tracking Number (MTN) exists and return basic details
-
-        Returns:
-            dict: object containing MTN details and confirmation if site exists
-        """
+    def check_mtn_exists(self, mtn: str) -> RcrainfoResponse[ManifestExistsResponse]:
+        """Check if Manifest Tracking Number (MTN) exists and return basic details"""
         endpoint = f"{self.base_url}v1/emanifest/manifest/mtn-exists/{mtn}"
         return self.__rcra_request("GET", endpoint)
 
diff --git a/emanifest-py/src/emanifest/types.py b/emanifest-py/src/emanifest/types.py
index dbf4f819..4fe50fb0 100644
--- a/emanifest-py/src/emanifest/types.py
+++ b/emanifest-py/src/emanifest/types.py
@@ -19,11 +19,15 @@ class RcraCodeDescription(TypedDict, total=False):
 
 
 class Phone(TypedDict, total=False):
+    """A RCRAInfo phone number"""
+
     number: Required[str]
     extension: Optional[str]
 
 
 class Contact(TypedDict, total=False):
+    """RCRAInfo user contact information"""
+
     firstName: str
     middleInitial: str
     lastName: str
@@ -33,11 +37,15 @@ class Contact(TypedDict, total=False):
 
 
 class RcraLocality(TypedDict, total=False):
+    """A RCRAInfo locality (state or country)"""
+
     code: Required[str]
     name: str
 
 
 class Address(TypedDict, total=False):
+    """An address in the RCRAInfo system"""
+
     address1: Required[str]
     address2: str
     city: str
@@ -50,6 +58,8 @@ class Address(TypedDict, total=False):
 
 
 class RcraSite(TypedDict):
+    """A site in the RCRAInfo system"""
+
     canEsign: bool
     contact: Contact
     epaSiteId: str
@@ -78,6 +88,8 @@ class SiteExistsResponse(TypedDict):
 
 
 class SiteSearchArgs(TypedDict, total=False):
+    """Search parameters for site search service"""
+
     epaSiteId: Optional[str]
     name: Optional[str]
     streetNumber: Optional[str]
@@ -90,6 +102,8 @@ class SiteSearchArgs(TypedDict, total=False):
 
 
 class UserSearchArgs(TypedDict, total=False):
+    """Search parameters for user search service"""
+
     userId: Optional[str]
     siteIds: Optional[List[str]]
     pageNumber: Optional[int]
@@ -301,6 +315,8 @@ class UILinkArgs(TypedDict, total=False):
 
 
 class DiscrepancyResidueInfo(TypedDict, total=False):
+    """Manifest Waste Discrepancy info"""
+
     wasteQuantity: bool
     wasteType: bool
     discrepancyComments: Optional[str]
@@ -309,11 +325,15 @@ class DiscrepancyResidueInfo(TypedDict, total=False):
 
 
 class DotInformation(TypedDict):
+    """Waste Line Department of Transportation Information"""
+
     idNumber: RcraCodeDescription
     printedDotInformation: str
 
 
 class Quantity(TypedDict, total=False):
+    """Waste Line Quantities"""
+
     containerNumber: int
     containerType: RcraCodeDescription
     quantity: int
@@ -321,6 +341,8 @@ class Quantity(TypedDict, total=False):
 
 
 class BrInfo(TypedDict, total=False):
+    """Biennial Report Information that can be added to a manifest"""
+
     density: Optional[float]
     densityUnitOfMeasurement: Optional[RcraCodeDescription]
     formCode: Optional[RcraCodeDescription]
@@ -330,6 +352,8 @@ class BrInfo(TypedDict, total=False):
 
 
 class HazardousWaste(TypedDict, total=False):
+    """Key codes that indicate the type of hazardous waste"""
+
     federalWasteCodes: List[RcraCodeDescription]
     tsdfStateWasteCodes: List[RcraCodeDescription]
     txWasteCodes: List[str]
@@ -337,12 +361,16 @@ class HazardousWaste(TypedDict, total=False):
 
 
 class Comment(TypedDict, total=False):
+    """A comment on a manifest or waste line"""
+
     label: Optional[str]
     description: Optional[str]
     handlerId: Optional[str]
 
 
 class AdditionalInfo(TypedDict, total=False):
+    """Additional Information structure for use on a manifest or individual waste line"""
+
     originalManifestTrackingNumbers: Optional[List[str]]
     newManifestDestination: Optional[str]
     consentNumber: Optional[str]
@@ -350,6 +378,8 @@ class AdditionalInfo(TypedDict, total=False):
 
 
 class PcbInfo(TypedDict, total=False):
+    """Polychlorinated biphenyls information on a manifest waste line"""
+
     loadType: Optional[RcraCodeDescription]
     articleContainerId: Optional[str]
     dateOfRemoval: Optional[str]
@@ -378,6 +408,8 @@ class Waste(TypedDict, total=False):
 
 
 class __BaseManifest(TypedDict, total=False):
+    """For Internal Use. The bulk of fields in the manifest except for the 'import' field"""
+
     createdDate: datetime | str
     updatedDate: datetime | str
     manifestTrackingNumber: str
@@ -406,3 +438,13 @@ class Manifest(__BaseManifest, ImportFieldMixin):
     """The RCRA uniform hazardous waste manifest"""
 
     pass
+
+
+class ManifestExistsResponse(TypedDict):
+    """manifest exists service response"""
+
+    manifestTrackingNumber: str
+    result: bool
+    originType: OriginType
+    submissionType: SubmissionType
+    status: Status