diff --git a/src/lib.rs b/src/lib.rs
index bbc6a1a..a64a3db 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -10,6 +10,7 @@ use std::{
 
 use crate::errors::Error;
 use crate::native::{
+    common::{Category, Comment, Entry, Field, LockState, Reason, State, Value},
     site_native::SiteNative,
     subject_native::{Form, Patient, SubjectNative},
     user_native::UserNative,
@@ -135,6 +136,7 @@ pub fn parse_site_native_file(xml_path: &Path) -> Result<SiteNative, Error> {
 ///                 form_index: 1,
 ///                 form_group: Some("Demographic".to_string()),
 ///                 form_state: "In-Work".to_string(),
+///                 lock_state: None,
 ///                 states: Some(vec![State {
 ///                     value: "form.state.in.work".to_string(),
 ///                     signer: "Paul Sanders - Project Manager".to_string(),
@@ -355,6 +357,7 @@ pub fn parse_site_native_file(xml_path: &Path) -> Result<SiteNative, Error> {
 ///                 form_index: 1,
 ///                 form_group: Some("Demographic".to_string()),
 ///                 form_state: "In-Work".to_string(),
+///                 lock_state: None,
 ///                 states: Some(vec![State {
 ///                     value: "form.state.in.work".to_string(),
 ///                     signer: "Paul Sanders - Project Manager".to_string(),
@@ -446,6 +449,7 @@ pub fn parse_subject_native_file(xml_path: &Path) -> Result<SubjectNative, Error
 /// ```
 /// use chrono::{DateTime, Utc};
 /// use prelude_xml_parser::parse_subject_native_string;
+/// use prelude_xml_parser::native::common::LockState;
 /// use prelude_xml_parser::native::subject_native::*;
 ///
 /// let xml = r#"<export_from_vision_EDC date="30-May-2024 10:35 -0500" createdBy="Paul Sanders" role="Project Manager" numberSubjectsProcessed="4">
@@ -506,6 +510,7 @@ pub fn parse_subject_native_file(xml_path: &Path) -> Result<SubjectNative, Error
 ///                 form_index: 1,
 ///                 form_group: Some("Day 0".to_string()),
 ///                 form_state: "In-Work".to_string(),
+///                 lock_state: None,
 ///                 states: Some(vec![State {
 ///                     value: "form.state.in.work".to_string(),
 ///                     signer: "Paul Sanders - Project Manager".to_string(),
@@ -575,6 +580,7 @@ pub fn parse_subject_native_file(xml_path: &Path) -> Result<SubjectNative, Error
 ///                 form_index: 1,
 ///                 form_group: Some("Day 0".to_string()),
 ///                 form_state: "In-Work".to_string(),
+///                 lock_state: None,
 ///                 states: Some(vec![State {
 ///                     value: "form.state.in.work".to_string(),
 ///                     signer: "Paul Sanders - Project Manager".to_string(),
@@ -626,8 +632,6 @@ pub fn parse_subject_native_string(xml_str: &str) -> Result<SubjectNative, Error
     parse_subject_native_streaming(Cursor::new(xml_str.as_bytes()))
 }
 
-use crate::native::common::{Category, Comment, Entry, Field, Reason, State, Value};
-
 fn parse_subject_native_streaming<R: std::io::BufRead>(reader: R) -> Result<SubjectNative, Error> {
     let mut xml_reader = Reader::from_reader(reader);
     xml_reader.config_mut().trim_text(true);
@@ -837,6 +841,13 @@ fn parse_subject_native_streaming<R: std::io::BufRead>(reader: R) -> Result<Subj
                             let state = State::from_attributes(attrs)?;
                             current_states.push(state);
                         }
+                        "lockState" if in_form => {
+                            let attrs = extract_attributes(e)?;
+                            let lock_state = LockState::from_attributes(attrs)?;
+                            if let Some(ref mut form) = current_form {
+                                form.lock_state = Some(lock_state);
+                            }
+                        }
                         "value" if in_entry => {
                             let attrs = extract_attributes(e)?;
                             let value = Value::from_attributes(attrs)?;
@@ -964,6 +975,7 @@ pub fn parse_user_native_file(xml_path: &Path) -> Result<UserNative, Error> {
 ///             form_index: 1,
 ///             form_group: None,
 ///             form_state: "In-Work".to_string(),
+///             lock_state: None,
 ///             states: Some(vec![State {
 ///                 value: "form.state.in.work".to_string(),
 ///                 signer: "Paul Sanders - Project Manager".to_string(),
diff --git a/src/native/common.rs b/src/native/common.rs
index 540d710..f6040a5 100644
--- a/src/native/common.rs
+++ b/src/native/common.rs
@@ -674,6 +674,7 @@ impl Form {
             form_group,
             form_state,
             states: None,
+            lock_state: None,
             categories: None,
         })
     }
@@ -780,6 +781,116 @@ impl State {
     }
 }
 
+#[cfg(not(feature = "python"))]
+#[derive(Clone, Debug, Deserialize, Serialize, PartialEq)]
+pub struct LockState {
+    #[serde(rename = "locked")]
+    #[serde(alias = "@locked")]
+    #[serde(alias = "locked")]
+    pub locked: bool,
+
+    #[serde(rename = "user")]
+    #[serde(alias = "@user")]
+    #[serde(alias = "user")]
+    #[serde(
+        default = "default_string_none",
+        deserialize_with = "deserialize_empty_string_as_none"
+    )]
+    pub user: Option<String>,
+
+    #[serde(rename = "userUniqueId")]
+    #[serde(alias = "@userUniqueId")]
+    #[serde(alias = "userUniqueId")]
+    #[serde(
+        default = "default_string_none",
+        deserialize_with = "deserialize_empty_string_as_none"
+    )]
+    pub user_unique_id: Option<String>,
+
+    #[serde(rename = "dateTimeChanged")]
+    #[serde(alias = "@dateTimeChanged")]
+    #[serde(alias = "dateTimeChanged")]
+    #[serde(
+        default = "default_datetime_none",
+        deserialize_with = "deserialize_empty_string_as_none_datetime"
+    )]
+    pub date_time_changed: Option<DateTime<Utc>>,
+}
+
+#[cfg(feature = "python")]
+#[derive(Clone, Debug, Deserialize, Serialize, PartialEq)]
+#[pyclass]
+pub struct LockState {
+    #[serde(rename = "locked")]
+    #[serde(alias = "@locked")]
+    #[serde(alias = "locked")]
+    pub locked: bool,
+
+    #[serde(rename = "user")]
+    #[serde(alias = "@user")]
+    #[serde(alias = "user")]
+    #[serde(
+        default = "default_string_none",
+        deserialize_with = "deserialize_empty_string_as_none"
+    )]
+    pub user: Option<String>,
+
+    #[serde(rename = "userUniqueId")]
+    #[serde(alias = "@userUniqueId")]
+    #[serde(alias = "userUniqueId")]
+    #[serde(
+        default = "default_string_none",
+        deserialize_with = "deserialize_empty_string_as_none"
+    )]
+    pub user_unique_id: Option<String>,
+
+    #[serde(rename = "dateTimeChanged")]
+    #[serde(alias = "@dateTimeChanged")]
+    #[serde(alias = "dateTimeChanged")]
+    #[serde(
+        default = "default_datetime_none",
+        deserialize_with = "deserialize_empty_string_as_none_datetime"
+    )]
+    pub date_time_changed: Option<DateTime<Utc>>,
+}
+
+#[cfg(feature = "python")]
+#[pymethods]
+impl LockState {
+    #[getter]
+    fn locked(&self) -> PyResult<bool> {
+        Ok(self.locked)
+    }
+
+    #[getter]
+    fn user(&self) -> PyResult<Option<String>> {
+        Ok(self.user.clone())
+    }
+
+    #[getter]
+    fn user_unique_id(&self) -> PyResult<Option<String>> {
+        Ok(self.user_unique_id.clone())
+    }
+
+    #[getter]
+    fn date_time_changed<'py>(&self, py: Python<'py>) -> PyResult<Option<Bound<'py, PyDateTime>>> {
+        to_py_datetime_option(py, &self.date_time_changed)
+    }
+
+    pub fn to_dict<'py>(&self, py: Python<'py>) -> PyResult<Bound<'py, PyDict>> {
+        let dict = PyDict::new(py);
+        dict.set_item("locked", self.locked)?;
+        dict.set_item("user", &self.user)?;
+        dict.set_item("user_unique_id", &self.user_unique_id)?;
+        dict.set_item(
+            "date_time_changed",
+            to_py_datetime_option(py, &self.date_time_changed)?,
+        )?;
+
+        Ok(dict)
+    }
+}
+
 #[cfg(not(feature = "python"))]
 #[derive(Clone, Debug, Deserialize, Serialize, PartialEq)]
 pub struct Form {
@@ -876,6 +987,9 @@ pub struct Form {
     #[serde(alias = "state")]
     pub states: Option<Vec<State>>,
 
+    #[serde(alias = "lockState")]
+    pub lock_state: Option<LockState>,
+
     #[serde(alias = "category")]
     pub categories: Option<Vec<Category>>,
 }
@@ -977,6 +1091,9 @@ pub struct Form {
     #[serde(alias = "state")]
     pub states: Option<Vec<State>>,
 
+    #[serde(alias = "lockState")]
+    pub lock_state: Option<LockState>,
+
     #[serde(alias = "category")]
     pub categories: Option<Vec<Category>>,
 }
@@ -1059,6 +1176,11 @@ impl Form {
         Ok(self.states.clone())
     }
 
+    #[getter]
+    fn lock_state(&self) -> PyResult<Option<LockState>> {
+        Ok(self.lock_state.clone())
+    }
+
     #[getter]
     fn categories(&self) -> PyResult<Option<Vec<Category>>> {
         Ok(self.categories.clone())
@@ -1098,6 +1220,12 @@ impl Form {
             dict.set_item("states", py.None())?;
         }
 
+        if let Some(lock_state) = &self.lock_state {
+            dict.set_item("lock_state", lock_state.to_dict(py)?)?;
+        } else {
+            dict.set_item("lock_state", py.None())?;
+        }
+
         if let Some(categories) = &self.categories {
             let mut category_dicts = Vec::new();
             for category in categories {
@@ -1140,6 +1268,33 @@ impl State {
     }
 }
 
+impl LockState {
+    pub fn from_attributes(
+        attrs: std::collections::HashMap<String, String>,
+    ) -> Result<Self, crate::errors::Error> {
+        let locked = attrs.get("locked").map(|s| s == "true").unwrap_or(false);
+        let user = attrs.get("user").filter(|s| !s.is_empty()).cloned();
+        let user_unique_id = attrs.get("userUniqueId").filter(|s| !s.is_empty()).cloned();
+
+        let date_time_changed = if let Some(dtc) = attrs.get("dateTimeChanged") {
+            if dtc.is_empty() {
+                None
+            } else {
+                parse_datetime_internal(dtc).ok()
+            }
+        } else {
+            None
+        };
+
+        Ok(LockState {
+            locked,
+            user,
+            user_unique_id,
+            date_time_changed,
+        })
+    }
+}
+
 impl Category {
     pub fn from_attributes(
         attrs: std::collections::HashMap<String, String>,
diff --git a/src/native/snapshots/prelude_xml_parser__native__subject_native__tests__deserialize_subject_native_json.snap b/src/native/snapshots/prelude_xml_parser__native__subject_native__tests__deserialize_subject_native_json.snap
index 22db3b7..9ecd936 100644
--- a/src/native/snapshots/prelude_xml_parser__native__subject_native__tests__deserialize_subject_native_json.snap
+++ b/src/native/snapshots/prelude_xml_parser__native__subject_native__tests__deserialize_subject_native_json.snap
@@ -31,6 +31,7 @@ patients:
             signer: Paul Sanders - Project Manager
             signerUniqueId: "1681162687395"
             dateSigned: "2023-04-15T16:09:02Z"
+        lock_state: ~
         categories:
           - name: Demographics
             categoryType: normal
@@ -80,6 +81,7 @@ patients:
             signer: Paul Sanders - Project Manager
             signerUniqueId: "1681162687395"
             dateSigned: "2023-04-16T16:10:02Z"
+        lock_state: ~
         categories:
           - name: Demographics
             categoryType: normal
diff --git a/src/native/snapshots/prelude_xml_parser__native__user_native__tests__deserialize_user_native_json.snap b/src/native/snapshots/prelude_xml_parser__native__user_native__tests__deserialize_user_native_json.snap
index 018d7ea..9d99ad8 100644
--- a/src/native/snapshots/prelude_xml_parser__native__user_native__tests__deserialize_user_native_json.snap
+++ b/src/native/snapshots/prelude_xml_parser__native__user_native__tests__deserialize_user_native_json.snap
@@ -27,6 +27,7 @@ users:
             signer: Paul Sanders - Project Manager
             signerUniqueId: "1681162687395"
             dateSigned: "2023-08-07T15:15:41Z"
+        lock_state: ~
         categories:
           - name: demographics
             categoryType: normal
diff --git a/tests/assets/subject_native.xml b/tests/assets/subject_native.xml
index b233a0b..a87afd6 100644
--- a/tests/assets/subject_native.xml
+++ b/tests/assets/subject_native.xml
@@ -4,6 +4,7 @@
   <patient patientId="ABC-001" uniqueId="1681574905819" whenCreated="2023-04-15 12:09:02 -0400" creator="Paul Sanders" siteName="Some Site" siteUniqueId="1681574834910" lastLanguage="" numberOfForms="6">
     <form name="day.0.form.name.demographics" lastModified="2023-04-15 12:09:15 -0400" whoLastModifiedName="Paul Sanders" whoLastModifiedRole="Project Manager" whenCreated="1681574905839" hasErrors="false" hasWarnings="false" locked="false" user="" dateTimeChanged="" formTitle="Demographics" formIndex="1" formGroup="Day 0" formState="In-Work">
       <state value="form.state.in.work" signer="Paul Sanders - Project Manager" signerUniqueId="1681162687395" dateSigned="2023-04-15 12:09:02 -0400" />
+      <lockState locked="true" user="Some User" userUniqueId="1630429016609" dateTimeChanged="2024-10-31 09:49:15 -0500" />
       <category name="Demographics" type="normal" highestIndex="0">
         <field name="breed" type="combo-box" dataType="string" errorCode="valid" whenCreated="2023-04-15 12:08:26 -0400" keepHistory="true">
           <entry id="1">