diff --git a/nullaway/src/main/java/com/uber/nullaway/Config.java b/nullaway/src/main/java/com/uber/nullaway/Config.java
index 3efefe47c2..b35abe69c3 100644
--- a/nullaway/src/main/java/com/uber/nullaway/Config.java
+++ b/nullaway/src/main/java/com/uber/nullaway/Config.java
@@ -240,6 +240,14 @@ public interface Config {
    */
   @Nullable String getCastToNonNullMethod();
 
+  /**
+   * Checks whether the <code>castToNonNull()</code> method should be treated as failing on null.
+   *
+   * @return true if <code>castToNonNull()</code> methods are guaranteed to throw when passed null,
+   *     false otherwise
+   */
+  boolean castToNonNullMethodFailsOnNull();
+
   /**
    * Gets the suppression name aliases.
    *
diff --git a/nullaway/src/main/java/com/uber/nullaway/DummyOptionsConfig.java b/nullaway/src/main/java/com/uber/nullaway/DummyOptionsConfig.java
index f564175788..ab16ec1d6b 100644
--- a/nullaway/src/main/java/com/uber/nullaway/DummyOptionsConfig.java
+++ b/nullaway/src/main/java/com/uber/nullaway/DummyOptionsConfig.java
@@ -179,6 +179,11 @@ public Set<String> getOptionalClassPaths() {
     throw new IllegalStateException(ERROR_MESSAGE);
   }
 
+  @Override
+  public boolean castToNonNullMethodFailsOnNull() {
+    throw new IllegalStateException(ERROR_MESSAGE);
+  }
+
   @Override
   public Set<String> getSuppressionNameAliases() {
     throw new IllegalStateException(ERROR_MESSAGE);
diff --git a/nullaway/src/main/java/com/uber/nullaway/ErrorProneCLIFlagsConfig.java b/nullaway/src/main/java/com/uber/nullaway/ErrorProneCLIFlagsConfig.java
index 73f5119d7a..109bcc8ddb 100644
--- a/nullaway/src/main/java/com/uber/nullaway/ErrorProneCLIFlagsConfig.java
+++ b/nullaway/src/main/java/com/uber/nullaway/ErrorProneCLIFlagsConfig.java
@@ -66,6 +66,8 @@ final class ErrorProneCLIFlagsConfig implements Config {
   static final String FL_NULLABLE_ANNOT = EP_FL_NAMESPACE + ":CustomNullableAnnotations";
   static final String FL_NONNULL_ANNOT = EP_FL_NAMESPACE + ":CustomNonnullAnnotations";
   static final String FL_CTNN_METHOD = EP_FL_NAMESPACE + ":CastToNonNullMethod";
+  static final String FL_CTNN_METHOD_FAILS_ON_NULL =
+      EP_FL_NAMESPACE + ":CastToNonNullMethodFailsOnNull";
   static final String FL_EXTERNAL_INIT_ANNOT = EP_FL_NAMESPACE + ":ExternalInitAnnotations";
   static final String FL_CONTRACT_ANNOT = EP_FL_NAMESPACE + ":CustomContractAnnotations";
   static final String FL_UNANNOTATED_CLASSES = EP_FL_NAMESPACE + ":UnannotatedClasses";
@@ -243,6 +245,7 @@ final class ErrorProneCLIFlagsConfig implements Config {
   private final ImmutableSet<String> externalInitAnnotations;
   private final ImmutableSet<String> contractAnnotations;
   private final @Nullable String castToNonNullMethod;
+  private final boolean castToNonNullMethodFailsOnNull;
   private final String autofixSuppressionComment;
   private final ImmutableSet<String> suppressionNameAliases;
   private final ImmutableSet<String> skippedLibraryModels;
@@ -312,6 +315,7 @@ final class ErrorProneCLIFlagsConfig implements Config {
         getPackagePattern(
             getFlagStringSet(flags, FL_EXCLUDED_FIELD_ANNOT, DEFAULT_EXCLUDED_FIELD_ANNOT));
     castToNonNullMethod = flags.get(FL_CTNN_METHOD).orElse(null);
+    castToNonNullMethodFailsOnNull = flags.getBoolean(FL_CTNN_METHOD_FAILS_ON_NULL).orElse(false);
     legacyAnnotationLocation = flags.getBoolean(FL_LEGACY_ANNOTATION_LOCATION).orElse(false);
     if (legacyAnnotationLocation && jspecifyMode) {
       throw new IllegalStateException(
@@ -554,6 +558,11 @@ public boolean assertsEnabled() {
     return castToNonNullMethod;
   }
 
+  @Override
+  public boolean castToNonNullMethodFailsOnNull() {
+    return castToNonNullMethodFailsOnNull;
+  }
+
   @Override
   public ImmutableSet<String> getSuppressionNameAliases() {
     return suppressionNameAliases;
diff --git a/nullaway/src/main/java/com/uber/nullaway/handlers/LibraryModelsHandler.java b/nullaway/src/main/java/com/uber/nullaway/handlers/LibraryModelsHandler.java
index 676923b926..3d2cbaa181 100644
--- a/nullaway/src/main/java/com/uber/nullaway/handlers/LibraryModelsHandler.java
+++ b/nullaway/src/main/java/com/uber/nullaway/handlers/LibraryModelsHandler.java
@@ -401,8 +401,32 @@ private void setUnconditionalArgumentNullness(
       AccessPath.AccessPathContext apContext) {
     ImmutableSet<Integer> requiredNonNullParameters =
         getOptLibraryModels(state.context).failIfNullParameters(callee);
+    Set<Integer> allNonNullParams;
+    if (config.castToNonNullMethodFailsOnNull()) {
+      ImmutableSet<Integer> castToNonNullParameters =
+          getOptLibraryModels(state.context).castToNonNullMethod(callee);
+      String cliCastToNonNull = config.getCastToNonNullMethod();
+      boolean isCliCastToNonNull =
+          cliCastToNonNull != null
+              && callee.getParameters().size() == 1
+              && cliCastToNonNull.equals(
+                  ASTHelpers.enclosingClass(callee) + "." + callee.getSimpleName());
+
+      if (castToNonNullParameters.isEmpty() && !isCliCastToNonNull) {
+        allNonNullParams = requiredNonNullParameters;
+      } else {
+        allNonNullParams = new HashSet<>(requiredNonNullParameters);
+        allNonNullParams.addAll(castToNonNullParameters);
+        if (isCliCastToNonNull) {
+          allNonNullParams.add(0);
+        }
+      }
+    } else {
+      allNonNullParams = requiredNonNullParameters;
+    }
+
     for (AccessPath accessPath :
-        accessPathsAtIndexes(requiredNonNullParameters, arguments, state, apContext)) {
+        accessPathsAtIndexes(allNonNullParams, arguments, state, apContext)) {
       bothUpdates.set(accessPath, NONNULL);
     }
   }
diff --git a/nullaway/src/test/java/com/uber/nullaway/CoreTests.java b/nullaway/src/test/java/com/uber/nullaway/CoreTests.java
index cc09f0b041..43cd3e8144 100644
--- a/nullaway/src/test/java/com/uber/nullaway/CoreTests.java
+++ b/nullaway/src/test/java/com/uber/nullaway/CoreTests.java
@@ -23,6 +23,7 @@
 package com.uber.nullaway;
 
 import java.util.Arrays;
+import java.util.List;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
@@ -397,6 +398,123 @@ Object test4(@Nullable Object o) {
         .doTest();
   }
 
+  @SuppressWarnings("deprecation")
+  @Test
+  public void testCastToNonNullPropagationDefault() {
+    defaultCompilationHelper
+        .addSourceFile("testdata/Util.java")
+        .addSourceLines(
+            "Test.java",
+            """
+            package com.uber;
+            import javax.annotation.Nullable;
+            import static com.uber.nullaway.testdata.Util.castToNonNull;
+            class Test {
+              static class Foo {
+                @Nullable String getToken() { return ""; }
+              }
+              void test(Foo value) {
+                if (castToNonNull(value.getToken()).contains("abc")) {
+                  // BUG: Diagnostic contains: dereferenced expression 'value.getToken()' is @Nullable
+                  value.getToken().length();
+                }
+              }
+            }
+            """)
+        .doTest();
+  }
+
+  @SuppressWarnings("deprecation")
+  @Test
+  public void testCastToNonNullPropagationExplicitFalse() {
+    makeTestHelperWithArgs(
+            List.of(
+                "-d",
+                temporaryFolder.getRoot().getAbsolutePath(),
+                "-XepOpt:NullAway:AnnotatedPackages=com.uber",
+                "-XepOpt:NullAway:CastToNonNullMethod=com.uber.nullaway.testdata.Util.castToNonNull",
+                "-XepOpt:NullAway:CastToNonNullMethodFailsOnNull=false"))
+        .addSourceFile("testdata/Util.java")
+        .addSourceLines(
+            "Test.java",
+            """
+            package com.uber;
+            import javax.annotation.Nullable;
+            import static com.uber.nullaway.testdata.Util.castToNonNull;
+            class Test {
+              static class Foo {
+                @Nullable String getToken() { return ""; }
+              }
+              void test(Foo value) {
+                if (castToNonNull(value.getToken()).contains("abc")) {
+                  // BUG: Diagnostic contains: dereferenced expression 'value.getToken()' is @Nullable
+                  value.getToken().length();
+                }
+              }
+            }
+            """)
+        .doTest();
+  }
+
+  @SuppressWarnings("deprecation")
+  @Test
+  public void testCastToNonNullPropagationFailsOnNullEnabled() {
+    makeTestHelperWithArgs(
+            List.of(
+                "-d",
+                temporaryFolder.getRoot().getAbsolutePath(),
+                "-XepOpt:NullAway:AnnotatedPackages=com.uber",
+                "-XepOpt:NullAway:CastToNonNullMethod=com.uber.nullaway.testdata.Util.castToNonNull",
+                "-XepOpt:NullAway:CastToNonNullMethodFailsOnNull=true"))
+        .addSourceFile("testdata/Util.java")
+        .addSourceLines(
+            "Test.java",
+            """
+            package com.uber;
+            import javax.annotation.Nullable;
+            import static com.uber.nullaway.testdata.Util.castToNonNull;
+            class Test {
+              static class Foo {
+                @Nullable String getToken() { return ""; }
+              }
+              void test(Foo value) {
+                if (castToNonNull(value.getToken()).contains("abc")) {
+                  value.getToken().length();
+                }
+              }
+            }
+            """)
+        .doTest();
+  }
+
+  @Test
+  public void testObjectsRequireNonNullPropagationUnchanged() {
+    makeTestHelperWithArgs(
+            List.of(
+                "-d",
+                temporaryFolder.getRoot().getAbsolutePath(),
+                "-XepOpt:NullAway:AnnotatedPackages=com.uber",
+                "-XepOpt:NullAway:CastToNonNullMethodFailsOnNull=false"))
+        .addSourceLines(
+            "Test.java",
+            """
+            package com.uber;
+            import java.util.Objects;
+            import javax.annotation.Nullable;
+            class Test {
+              static class Foo {
+                @Nullable String getToken() { return ""; }
+              }
+              void test(Foo value) {
+                if (Objects.requireNonNull(value.getToken()).contains("abc")) {
+                  value.getToken().length();
+                }
+              }
+            }
+            """)
+        .doTest();
+  }
+
   @Test
   public void testReadStaticInConstructor() {
     defaultCompilationHelper