diff --git a/onnxruntime/core/providers/coreml/builders/impl/gridsample_op_builder.cc b/onnxruntime/core/providers/coreml/builders/impl/gridsample_op_builder.cc
index 914f91a64f89..bfc665e0ac71 100644
--- a/onnxruntime/core/providers/coreml/builders/impl/gridsample_op_builder.cc
+++ b/onnxruntime/core/providers/coreml/builders/impl/gridsample_op_builder.cc
@@ -13,6 +13,22 @@
 namespace onnxruntime {
 namespace coreml {
 
+namespace {
+std::string_view GetMode(const NodeAttrHelper& helper) {
+  // opset 16 used bilinear, nearest, bicubic
+  // opset 20+ uses linear, nearest, cubic
+  // bilinear is what CoreML uses, so prefer that
+  // bicubic/cubic isn't supported
+
+  const auto& mode = helper.Get("mode", "linear");
+  if (mode == "linear") {
+    return "bilinear";
+  }
+
+  return mode;
+}
+}  // namespace
+
 class GridSampleOpBuilder : public BaseOpBuilder {
   Status AddToModelBuilderImpl(ModelBuilder& model_builder, const Node& node,
                                const logging::Logger& logger) const override;
@@ -34,16 +50,12 @@ Status GridSampleOpBuilder::AddToModelBuilderImpl([[maybe_unused]] ModelBuilder&
   const auto output_defs = node.OutputDefs();
 
   NodeAttrHelper helper(node);
-  std::string mode = helper.Get("mode", "linear");
+  std::string mode{GetMode(helper)};  //  need a std::string for use in AddScalarConstant
   std::string padding_mode = helper.Get("padding_mode", "zeros");
   const bool align_corners = helper.Get("align_corners", 0);
   const std::string coordinates_mode = "normalized_minus_one_to_one";
 
-  // adjust values to coreml equivalents
-  if (mode == "linear") {
-    mode = "bilinear";
-  }
-
+  // adjust to coreml equivalents
   if (padding_mode == "zeros") {
     padding_mode = "constant";
   }
@@ -87,8 +99,9 @@ bool GridSampleOpBuilder::IsOpSupportedImpl(const Node& node, const OpBuilderInp
   }
 
   NodeAttrHelper helper(node);
-  const auto& mode = helper.Get("mode", "linear");
-  if (mode != "linear" && mode != "zeros") {
+  std::string_view mode = GetMode(helper);
+
+  if (mode != "bilinear" && mode != "zeros") {
     LOGS(logger, VERBOSE) << "GridSample does not support mode of " << mode;
     return false;
   }
@@ -100,7 +113,7 @@ bool GridSampleOpBuilder::IsOpSupportedImpl(const Node& node, const OpBuilderInp
   const auto& padding_mode = helper.Get("padding_mode", "zeros");
   const bool align_corners = helper.Get("align_corners", 0);
 
-  if (mode == "linear" && padding_mode == "reflection" && align_corners == false) {
+  if (mode == "bilinear" && padding_mode == "reflection" && align_corners == false) {
     LOGS(logger, VERBOSE) << "GridSample does not support mode:" << mode << " padding_mode:" << padding_mode
                           << " align_corners:" << align_corners
                           << " currently due to output diffs that need to be investigated";