diff --git a/wpilibc/src/main/native/include/frc/filters/Filter.h b/wpilibc/src/main/native/include/frc/filters/Filter.h
index b0c0c1145a..b200407f39 100644
--- a/wpilibc/src/main/native/include/frc/filters/Filter.h
+++ b/wpilibc/src/main/native/include/frc/filters/Filter.h
@@ -1,5 +1,5 @@
 /*----------------------------------------------------------------------------*/
-/* Copyright (c) 2015-2018 FIRST. All Rights Reserved.                        */
+/* Copyright (c) 2015-2019 FIRST. All Rights Reserved.                        */
 /* Open Source Software - may be modified and shared by FRC teams. The code   */
 /* must be accompanied by the FIRST BSD license file in the root directory of */
 /* the project.                                                               */
@@ -9,6 +9,8 @@
 
 #include <memory>
 
+#include <wpi/deprecated.h>
+
 #include "frc/PIDSource.h"
 
 namespace frc {
@@ -18,7 +20,9 @@ namespace frc {
  */
 class Filter : public PIDSource {
  public:
+  WPI_DEPRECATED("This class is no longer used.")
   explicit Filter(PIDSource& source);
+  WPI_DEPRECATED("This class is no longer used.")
   explicit Filter(std::shared_ptr<PIDSource> source);
   virtual ~Filter() = default;
 
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/filters/Filter.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/filters/Filter.java
index 26312f899f..257d36a684 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/filters/Filter.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/filters/Filter.java
@@ -1,5 +1,5 @@
 /*----------------------------------------------------------------------------*/
-/* Copyright (c) 2015-2018 FIRST. All Rights Reserved.                        */
+/* Copyright (c) 2015-2019 FIRST. All Rights Reserved.                        */
 /* Open Source Software - may be modified and shared by FRC teams. The code   */
 /* must be accompanied by the FIRST BSD license file in the root directory of */
 /* the project.                                                               */
@@ -12,7 +12,10 @@ import edu.wpi.first.wpilibj.PIDSourceType;
 
 /**
  * Superclass for filters.
+ *
+ * @deprecated This class is no longer used.
  */
+@Deprecated(since = "2020", forRemoval = true)
 public abstract class Filter implements PIDSource {
   private final PIDSource m_source;