diff --git a/mlir/include/mlir/Dialect/OpenACC/OpenACC.h b/mlir/include/mlir/Dialect/OpenACC/OpenACC.h
--- a/mlir/include/mlir/Dialect/OpenACC/OpenACC.h
+++ b/mlir/include/mlir/Dialect/OpenACC/OpenACC.h
@@ -73,6 +73,11 @@
 std::optional<mlir::acc::DataClause>
 getDataClause(mlir::Operation *accDataEntryOp);
 
+/// Used to find out whether data operation is implicit.
+/// Returns false if not a data operation or if it is a data operation without
+/// implicit flag.
+bool getImplicitFlag(mlir::Operation *accDataEntryOp);
+
 /// Used to obtain the attribute name for declare.
 static constexpr StringLiteral getDeclareAttrName() {
   return StringLiteral("acc.declare");
diff --git a/mlir/include/mlir/Dialect/OpenACC/OpenACCOps.td b/mlir/include/mlir/Dialect/OpenACC/OpenACCOps.td
--- a/mlir/include/mlir/Dialect/OpenACC/OpenACCOps.td
+++ b/mlir/include/mlir/Dialect/OpenACC/OpenACCOps.td
@@ -131,8 +131,13 @@
 // easier to find out whether the variable is in a declare clause and what kind
 // of clause it is.
 def DeclareAttr : OpenACC_Attr<"Declare", "declare"> {
-  let parameters = (ins "DataClauseAttr":$dataClause);
+  let parameters = (ins "DataClauseAttr":$dataClause,
+                        DefaultValuedParameter<"bool", "false">:$implicit);
   let assemblyFormat = "`<` struct(params) `>`";
+  let builders = [AttrBuilder<(ins "DataClauseAttr":$dataClause), [{
+      return $_get($_ctxt, dataClause, /*implicit=*/false);
+    }]>
+  ];
 }
 
 // Attribute to attach functions that perform the pre/post allocation actions or
diff --git a/mlir/lib/Dialect/OpenACC/IR/OpenACC.cpp b/mlir/lib/Dialect/OpenACC/IR/OpenACC.cpp
--- a/mlir/lib/Dialect/OpenACC/IR/OpenACC.cpp
+++ b/mlir/lib/Dialect/OpenACC/IR/OpenACC.cpp
@@ -1015,11 +1015,21 @@
     if (!declareAttribute)
       return op.emitError(
           "expect declare attribute on variable in declare operation");
-    if (mlir::cast<mlir::acc::DeclareAttr>(declareAttribute)
-            .getDataClause()
-            .getValue() != dataClauseOptional.value())
+
+    auto declAttr = mlir::cast<mlir::acc::DeclareAttr>(declareAttribute);
+    if (declAttr.getDataClause().getValue() != dataClauseOptional.value())
       return op.emitError(
           "expect matching declare attribute on variable in declare operation");
+
+    // If the variable is marked with implicit attribute, the matching declare
+    // data action must also be marked implicit. The reverse is not checked
+    // since implicit data action may be inserted to do actions like updating
+    // device copy, in which case the variable is not necessarily implicitly
+    // declare'd.
+    if (declAttr.getImplicit() &&
+        declAttr.getImplicit() != acc::getImplicitFlag(operand.getDefiningOp()))
+      return op.emitError(
+          "implicitness must match between declare op and flag on variable");
   }
 
   return success();
@@ -1234,3 +1244,11 @@
           .Default([&](mlir::Operation *) { return std::nullopt; })};
   return dataClause;
 }
+
+bool mlir::acc::getImplicitFlag(mlir::Operation *accDataEntryOp) {
+  auto implicit{llvm::TypeSwitch<mlir::Operation *, bool>(accDataEntryOp)
+                    .Case<ACC_DATA_ENTRY_OPS>(
+                        [&](auto entry) { return entry.getImplicit(); })
+                    .Default([&](mlir::Operation *) { return false; })};
+  return implicit;
+}
diff --git a/mlir/test/Dialect/OpenACC/ops.mlir b/mlir/test/Dialect/OpenACC/ops.mlir
--- a/mlir/test/Dialect/OpenACC/ops.mlir
+++ b/mlir/test/Dialect/OpenACC/ops.mlir
@@ -1684,12 +1684,17 @@
   %numGangs = arith.constant 10 : i64
   %numWorkers = arith.constant 10 : i64
 
+  %c20 = arith.constant 20 : i32
+  %alloc = llvm.alloca %c20 x i32 { acc.declare = #acc.declare<dataClause = acc_create, implicit = true> } : (i32) -> !llvm.ptr<i32>
+  %createlocal = acc.create varPtr(%alloc : !llvm.ptr<i32>) -> !llvm.ptr<i32> {implicit = true}
+
   %pa = acc.present varPtr(%a : memref<10x10xf32>) -> memref<10x10xf32>
   %pb = acc.present varPtr(%b : memref<10x10xf32>) -> memref<10x10xf32>
   %pc = acc.present varPtr(%c : memref<10xf32>) -> memref<10xf32>
   %pd = acc.present varPtr(%d : memref<10xf32>) -> memref<10xf32>
-  acc.declare dataOperands(%pa, %pb, %pc, %pd: memref<10x10xf32>, memref<10x10xf32>, memref<10xf32>, memref<10xf32>) {
+  acc.declare dataOperands(%pa, %pb, %pc, %pd, %createlocal: memref<10x10xf32>, memref<10x10xf32>, memref<10xf32>, memref<10xf32>, !llvm.ptr<i32>) {
   }
+
   return
 }