diff --git a/cwms-data-api/src/main/java/cwms/cda/api/Controllers.java b/cwms-data-api/src/main/java/cwms/cda/api/Controllers.java
index 5d4b3abfb..060e476a8 100644
--- a/cwms-data-api/src/main/java/cwms/cda/api/Controllers.java
+++ b/cwms-data-api/src/main/java/cwms/cda/api/Controllers.java
@@ -31,6 +31,8 @@
 import cwms.cda.api.enums.VersionType;
 import cwms.cda.api.errors.RequiredQueryParameterException;
 import cwms.cda.data.dao.JooqDao;
+import cwms.cda.formatters.ContentType;
+import cwms.cda.formatters.Formats;
 import cwms.cda.helpers.DateUtils;
 import io.javalin.core.validation.JavalinValidation;
 import io.javalin.core.validation.Validator;
@@ -38,6 +40,7 @@
 import java.time.Instant;
 import java.time.ZonedDateTime;
 import org.jetbrains.annotations.Nullable;
+
 import static com.codahale.metrics.MetricRegistry.name;
 
 public final class Controllers {
@@ -168,6 +171,10 @@ public final class Controllers {
     public static final String EXCLUDE_EMPTY = "exclude-empty";
     public static final String DEFAULT_VALUE = "default-value";
 
+    private static final String DEPRECATED_HEADER = "CWMS-DATA-Format-Deprecated";
+    private static final String DEPRECATED_TAB = "2024-11-01 TAB is not used often.";
+    private static final String DEPRECATED_CSV = "2024-11-01 CSV is not used often.";
+
 
     static {
         JavalinValidation.register(JooqDao.DeleteMethod.class, Controllers::getDeleteMethod);
@@ -355,5 +362,15 @@ public static Instant requiredInstant(Context ctx, String param) {
         return retval;
     }
 
-
+    static void addDeprecatedContentTypeWarning(Context ctx, ContentType type)
+    {
+        if (type.getType().equalsIgnoreCase(Formats.TAB))
+        {
+            ctx.res.addHeader(DEPRECATED_HEADER, DEPRECATED_TAB);
+        }
+        else if (type.getType().equalsIgnoreCase(Formats.CSV))
+        {
+            ctx.res.addHeader(DEPRECATED_HEADER, DEPRECATED_CSV);
+        }
+    }
 }
diff --git a/cwms-data-api/src/main/java/cwms/cda/api/OfficeController.java b/cwms-data-api/src/main/java/cwms/cda/api/OfficeController.java
index 53b242928..ac60a0232 100644
--- a/cwms-data-api/src/main/java/cwms/cda/api/OfficeController.java
+++ b/cwms-data-api/src/main/java/cwms/cda/api/OfficeController.java
@@ -111,6 +111,8 @@ public void getAll(Context ctx) {
 
             String result = Formats.format(contentType, offices, Office.class);
 
+            Controllers.addDeprecatedContentTypeWarning(ctx, contentType);
+
             ctx.result(result).contentType(contentType.toString());
             requestResultSize.update(result.length());
 
@@ -154,6 +156,7 @@ public void getOne(Context ctx, String officeId) {
                 String formatHeader = ctx.header(Header.ACCEPT);
                 ContentType contentType = Formats.parseHeaderAndQueryParm(formatHeader, formatParm, Office.class);
                 String result = Formats.format(contentType, office.get());
+                Controllers.addDeprecatedContentTypeWarning(ctx, contentType);
                 ctx.result(result).contentType(contentType.toString());
 
                 requestResultSize.update(result.length());