diff --git a/source/frontend/src/features/mapSideBar/acquisition/common/models.test.ts b/source/frontend/src/features/mapSideBar/acquisition/common/models.test.ts
new file mode 100644
index 0000000000..2d32f31b9b
--- /dev/null
+++ b/source/frontend/src/features/mapSideBar/acquisition/common/models.test.ts
@@ -0,0 +1,21 @@
+import { AcquisitionTeamFormModel } from './models';
+
+describe('acquisition model tests', () => {
+  it('omits the primary contact if unset', () => {
+    let model = new AcquisitionTeamFormModel('testType');
+    model.primaryContactId = '';
+    expect(model.toApi(1)?.primaryContactId).toBeUndefined();
+  });
+
+  it('omits the primary contact if null', () => {
+    let model = new AcquisitionTeamFormModel('testType');
+    model.primaryContactId = null as any;
+    expect(model.toApi(1)?.primaryContactId).toBeUndefined();
+  });
+
+  it('omits the primary contact if undefined', () => {
+    let model = new AcquisitionTeamFormModel('testType');
+    model.primaryContactId = undefined as any;
+    expect(model.toApi(1)?.primaryContactId).toBeUndefined();
+  });
+});
diff --git a/source/frontend/src/features/mapSideBar/acquisition/common/models.ts b/source/frontend/src/features/mapSideBar/acquisition/common/models.ts
index ecd7f2cecf..658f5d7c0b 100644
--- a/source/frontend/src/features/mapSideBar/acquisition/common/models.ts
+++ b/source/frontend/src/features/mapSideBar/acquisition/common/models.ts
@@ -42,7 +42,7 @@ export class AcquisitionTeamFormModel {
       person: undefined,
       organizationId: organizationId ?? undefined,
       organization: undefined,
-      primaryContactId: this.primaryContactId !== '' ? Number(this.primaryContactId) : undefined,
+      primaryContactId: !isNaN(+this.primaryContactId) ? Number(this.primaryContactId) : undefined,
       teamProfileType: toTypeCode(this.contactTypeCode),
       teamProfileTypeCode: this.contactTypeCode,
     };