diff --git a/app/components/ClinicUserEdit.js b/app/components/ClinicUserEdit.js
index e1145d488..276ffb3d1 100644
--- a/app/components/ClinicUserEdit.js
+++ b/app/components/ClinicUserEdit.js
@@ -52,6 +52,36 @@ function validateForm(values, props){
   if(mrnRequired && !values.mrn){
     errors.mrn = i18n.t('Patient\'s MRN is required');
   }
+  // mrn needs to be uppercase alphanumeric between 6 and 25 characters
+  if(values.mrn && !/^[A-Z0-9]{6,25}$/.test(values.mrn)){
+    errors.mrn = (
+      <div>
+        {i18n.t('Patient’s MRN is invalid. MRN must meet the following criteria:')}
+        <ul>
+          <li>{i18n.t('All upper case letters or numbers')}</li>
+          <li>{i18n.t('Minimum length: 6 characters')}</li>
+          <li>{i18n.t('Maximum length: 25 characters')}</li>
+          <li>{i18n.t('No spaces')}</li>
+        </ul>
+      </div>
+    );
+  }
+  // mrn needs to be unique
+  if (values.mrn && props.selectedClinicId) {
+    var { targetId } = props;
+    var patients = _.get(
+      props.clinics,
+      [props.selectedClinicId, 'patients'],
+      {}
+    );
+    var filteredPatients = _.reject(patients, { id: targetId });
+    var mrnExists = _.find(filteredPatients, { mrn: values.mrn });
+    if (mrnExists) {
+      errors.mrn = i18n.t(
+        'This MRN is already in use. Please enter a valid MRN.'
+      );
+    }
+  }
   return errors;
 }
 
@@ -119,6 +149,57 @@ class ClinicUserEdit extends React.Component {
     clinics: PropTypes.object.isRequired,
   };
 
+  static defaultProps = {
+    searchDebounceMs: 1000,
+  };
+
+  constructor(props) {
+    super(props);
+    const { targetId, memberships, selectedClinicId, clinics } = props;
+    this.state = {
+      searchText: '',
+      updateTrigger: false,
+      isCustodialAccount: this.isCustodialAccount(memberships, targetId, selectedClinicId, clinics)
+    };
+  };
+
+  isCustodialAccount = (memberships, targetId, selectedClinicId, clinics) => {
+    return (
+      _.has(_.get(memberships, [targetId, 'permissions']), 'custodian') ||
+      (selectedClinicId &&
+        _.has(
+          _.get(clinics, [
+            selectedClinicId,
+            'patients',
+            targetId,
+            'permissions',
+          ]),
+          'custodian'
+        ))
+    );
+  };
+
+  componentDidUpdate(prevProps) {
+    const { targetId, memberships, selectedClinicId, clinics } = this.props;
+    if (
+      this.props.working.fetchingPatientsForClinic.inProgress === false &&
+      prevProps.working.fetchingPatientsForClinic.inProgress === true
+    ) {
+      this.props.change('_forceValidation', Date.now());
+    }
+
+    if (this.props.targetId !== prevProps.targetId) {
+      this.setState({
+        isCustodialAccount: this.isCustodialAccount(
+          memberships,
+          targetId,
+          selectedClinicId,
+          clinics
+        )
+      });
+    }
+  };
+
   handleCancel = () => {
     if(this.props.working.creatingClinicCustodialAccount.notification) {
       this.props.acknowledgeNotification();
@@ -174,6 +255,22 @@ class ClinicUserEdit extends React.Component {
     }
   };
 
+  handleSearchChange = () => _.debounce((e) => {
+    let searchText = e.target.value;
+    const {fetchPatientsForClinic, selectedClinicId, targetId} = this.props;
+    if(searchText !== this.state.searchText){
+      if(_.isEmpty(searchText)){
+        if(!targetId){
+          this.setState({searchText});
+          fetchPatientsForClinic(selectedClinicId);
+        }
+      } else {
+        this.setState({searchText});
+        fetchPatientsForClinic(selectedClinicId, {search: searchText});
+      }
+    }
+  }, this.props.searchDebounceMs);
+
   renderCreateError = () => {
     if (
       this.props.createCustodialAccountErrorDismissed ||
@@ -286,23 +383,12 @@ class ClinicUserEdit extends React.Component {
   };
 
   render() {
-    const { handleSubmit, targetId, memberships, clinics, selectedClinicId } = this.props;
-    const isCustodialAccount =
-      _.has(_.get(memberships, [targetId, 'permissions']), 'custodian') ||
-      (selectedClinicId &&
-        _.has(
-          _.get(clinics, [
-            selectedClinicId,
-            'patients',
-            targetId,
-            'permissions',
-          ]),
-          'custodian'
-        ));
+    const { handleSubmit, targetId, clinics, selectedClinicId } = this.props;
+
     const titleText = targetId
       ? i18n.t('Edit patient account')
       : i18n.t('Create a new patient account');
-    const editable = targetId ? isCustodialAccount : true;
+    const editable = targetId ? this.state.isCustodialAccount : true;
     const mrnRequired = _.get(
       clinics,
       [selectedClinicId, 'mrnSettings', 'required'],
@@ -346,6 +432,7 @@ class ClinicUserEdit extends React.Component {
               name="mrn"
               component={renderInput}
               props={{ disabled: !editable }}
+              onChange={this.handleSearchChange()}
             />
           </div>
           <div className={styles.inputWrap}>
diff --git a/app/containers/ClinicUserEditPage.js b/app/containers/ClinicUserEditPage.js
index 6d50d7666..8d66cfc39 100644
--- a/app/containers/ClinicUserEditPage.js
+++ b/app/containers/ClinicUserEditPage.js
@@ -36,30 +36,46 @@ export class ClinicUserEditPage extends Component {
   };
 
   render() {
-    const { allUsers, uploadTargetUser, memberships } = this.props;
+    const {
+      allUsers,
+      uploadTargetUser,
+      memberships,
+      loggedInUser,
+      createCustodialAccountErrorMessage,
+      createCustodialAccountErrorDismissed,
+      updateProfileErrorMessage,
+      updateProfileErrorDismissed,
+      selectedClinicId,
+      clinics,
+      working,
+      async,
+      sync
+    } = this.props;
+
     return (
       <div>
         <ClinicUserEdit
           targetId={uploadTargetUser}
           allUsers={allUsers}
           memberships={memberships}
-          loggedInUser={this.props.loggedInUser}
-          createUser={this.props.async.createCustodialAccount}
-          createClinicUser={this.props.async.createClinicCustodialAccount}
-          updateUser={this.props.async.clickEditUserNext}
-          updateClinicPatient={this.props.async.clickClinicEditUserNext}
+          loggedInUser={loggedInUser}
+          createUser={async.createCustodialAccount}
+          createClinicUser={async.createClinicCustodialAccount}
+          updateUser={async.clickEditUserNext}
+          updateClinicPatient={async.clickClinicEditUserNext}
           cancelEdit={_.partial(this.handleClickChangePerson, {metric: {eventName: metrics.CLINIC_ADD_CANCEL}})}
-          createCustodialAccountErrorMessage={this.props.createCustodialAccountErrorMessage}
-          createCustodialAccountErrorDismissed={this.props.createCustodialAccountErrorDismissed}
-          updateProfileErrorMessage={this.props.updateProfileErrorMessage}
-          updateProfileErrorDismissed={this.props.updateProfileErrorDismissed}
-          dismissCreateCustodialAccountError={this.props.sync.dismissCreateCustodialAccountError}
-          dismissUpdateProfileError={this.props.sync.dismissUpdateProfileError}
-          onSubmitFail={this.props.sync.clinicInvalidDate}
-          selectedClinicId={this.props.selectedClinicId}
-          clinics={this.props.clinics}
-          working={this.props.working}
-          acknowledgeNotification={this.props.sync.acknowledgeNotification} />
+          createCustodialAccountErrorMessage={createCustodialAccountErrorMessage}
+          createCustodialAccountErrorDismissed={createCustodialAccountErrorDismissed}
+          updateProfileErrorMessage={updateProfileErrorMessage}
+          updateProfileErrorDismissed={updateProfileErrorDismissed}
+          dismissCreateCustodialAccountError={sync.dismissCreateCustodialAccountError}
+          dismissUpdateProfileError={sync.dismissUpdateProfileError}
+          onSubmitFail={sync.clinicInvalidDate}
+          selectedClinicId={selectedClinicId}
+          clinics={clinics}
+          working={working}
+          acknowledgeNotification={sync.acknowledgeNotification}
+          fetchPatientsForClinic={async.fetchPatientsForClinic} />
       </div>
     );
   }
diff --git a/app/package.json b/app/package.json
index 53e21a984..e6a354a56 100644
--- a/app/package.json
+++ b/app/package.json
@@ -1,7 +1,7 @@
 {
   "name": "tidepool-uploader",
   "productName": "tidepool-uploader",
-  "version": "2.55.1-tandem-compatibility.updates.1",
+  "version": "2.55.1-mrn-validation.2",
   "description": "Tidepool Project Universal Uploader",
   "main": "./main.prod.js",
   "author": {
diff --git a/package.json b/package.json
index f85201ed2..b4a35e18c 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "tidepool-uploader",
-  "version": "2.55.1-tandem-compatibility.updates.1",
+  "version": "2.55.1-mrn-validation.2",
   "description": "Tidepool Project Universal Uploader",
   "private": true,
   "main": "main.prod.js",
diff --git a/styles/components/ClinicUserEdit.module.less b/styles/components/ClinicUserEdit.module.less
index f9fbd64a5..fdeefaecc 100644
--- a/styles/components/ClinicUserEdit.module.less
+++ b/styles/components/ClinicUserEdit.module.less
@@ -126,6 +126,11 @@
 .validationError {
   color: @red-error;
   margin-top: 10px;
+
+  ul {
+    padding-left: 20px;
+    margin-top: 0px;
+  }
 }
 
 .iconClose {