Index: clang/lib/Format/TokenAnnotator.cpp
===================================================================
--- clang/lib/Format/TokenAnnotator.cpp
+++ clang/lib/Format/TokenAnnotator.cpp
@@ -847,6 +847,7 @@
     unsigned CommaCount = 0;
     while (CurrentToken) {
       if (CurrentToken->is(tok::r_brace)) {
+        Scopes.pop_back();
         assert(OpeningBrace.Optional == CurrentToken->Optional);
         OpeningBrace.MatchingParen = CurrentToken;
         CurrentToken->MatchingParen = &OpeningBrace;
@@ -1146,6 +1147,27 @@
         if (Previous && Previous->getType() != TT_DictLiteral)
           Previous->setType(TT_SelectorName);
       }
+      switch (Tok->getType()) {
+      case TT_FunctionLBrace:
+      case TT_LambdaLBrace:
+        Scopes.push_back(ScopeType::Function);
+        break;
+      case TT_ClassLBrace:
+      case TT_StructLBrace:
+      case TT_UnionLBrace:
+        Scopes.push_back(ScopeType::Class);
+        break;
+      case TT_EnumLBrace:
+      case TT_ControlStatementLBrace:
+      case TT_ElseLBrace:
+      case TT_BracedListLBrace:
+      case TT_CompoundRequirementLBrace:
+      case TT_ObjCBlockLBrace:
+      case TT_RecordLBrace:
+      case TT_RequiresExpressionLBrace:
+      default:
+        Scopes.push_back(ScopeType::Other);
+      }
       if (!parseBrace())
         return false;
       break;
@@ -1176,6 +1198,7 @@
     case tok::r_square:
       return false;
     case tok::r_brace:
+      Scopes.pop_back();
       // Lines can start with '}'.
       if (Tok->Previous)
         return false;
@@ -1643,6 +1666,17 @@
     } ContextType = Unknown;
   };
 
+  enum class ScopeType : std::int8_t {
+    // Not contained within scope block.
+    None,
+    // Contained in class declaration/definition.
+    Class,
+    // Contained within function definition.
+    Function,
+    // Contained within other scope block (loop, if/else, etc).
+    Other,
+  };
+
   /// Puts a new \c Context onto the stack \c Contexts for the lifetime
   /// of each instance.
   struct ScopedContextCreator {
@@ -2446,6 +2480,25 @@
     if (IsExpression && !Contexts.back().CaretFound)
       return TT_BinaryOperator;
 
+    // Opeartors at class scope are likely pointer or reference members.
+    if (Scopes.back() == ScopeType::Class)
+      return TT_PointerOrReference;
+
+    // It's more likely that & represents operator& than an uninitialized
+    // reference.
+    if (Tok.is(tok::amp) && (PrevToken && PrevToken->Tok.isAnyIdentifier()) &&
+        (!PrevToken->getPreviousNonComment() ||
+         PrevToken->getPreviousNonComment()->isOneOf(tok::amp, tok::period,
+                                                     tok::arrow, tok::arrowstar,
+                                                     tok::periodstar)) &&
+        (NextToken && NextToken->Tok.isAnyIdentifier()) &&
+        (NextToken->getNextNonComment() &&
+         (NextToken->getNextNonComment()->isOneOf(
+             tok::amp, tok::semi, tok::period, tok::arrow, tok::arrowstar,
+             tok::periodstar)))) {
+      return TT_BinaryOperator;
+    }
+
     return TT_PointerOrReference;
   }
 
@@ -2476,6 +2529,7 @@
   }
 
   SmallVector<Context, 8> Contexts;
+  static SmallVector<ScopeType, 8> Scopes;
 
   const FormatStyle &Style;
   AnnotatedLine &Line;
@@ -2722,6 +2776,9 @@
   FormatToken *Current;
 };
 
+SmallVector<AnnotatingParser::ScopeType, 8> AnnotatingParser::Scopes = {
+    AnnotatingParser::ScopeType::None};
+
 } // end anonymous namespace
 
 void TokenAnnotator::setCommentLineLevels(
@@ -2875,6 +2932,7 @@
     return true;
   if (Next->Next == Next->MatchingParen)
     return true; // Empty parentheses.
+
   // If there is an &/&& after the r_paren, this is likely a function.
   if (Next->MatchingParen->Next &&
       Next->MatchingParen->Next->is(TT_PointerOrReference)) {
@@ -3661,6 +3719,7 @@
   }
   if (Left.is(tok::l_brace) && Right.is(tok::r_brace))
     return !Left.Children.empty(); // No spaces in "{}".
+
   if ((Left.is(tok::l_brace) && Left.isNot(BK_Block)) ||
       (Right.is(tok::r_brace) && Right.MatchingParen &&
        Right.MatchingParen->isNot(BK_Block))) {
@@ -4855,6 +4914,7 @@
       return Style.BreakBeforeBinaryOperators != FormatStyle::BOS_None;
     if (Right.is(Keywords.kw_as))
       return false; // must not break before as in 'x as type' casts
+
     if (Right.isOneOf(Keywords.kw_extends, Keywords.kw_infer)) {
       // extends and infer can appear as keywords in conditional types:
       //   https://www.typescriptlang.org/docs/handbook/release-notes/typescript-2-8.html#conditional-types
Index: clang/unittests/Format/FormatTest.cpp
===================================================================
--- clang/unittests/Format/FormatTest.cpp
+++ clang/unittests/Format/FormatTest.cpp
@@ -11267,6 +11267,13 @@
 
   verifyFormat("int operator()(T (&&)[N]) { return 1; }");
   verifyFormat("int operator()(T (&)[N]) { return 0; }");
+
+  verifyFormat("val1 & val2;");
+  verifyFormat("val1 & val2 & val3;");
+  verifyFormat("class c {\n"
+               "  void func(type &a) { a & member; }\n"
+               "  anotherType &member;\n"
+               "}");
 }
 
 TEST_F(FormatTest, UnderstandsAttributes) {
Index: clang/unittests/Format/TokenAnnotatorTest.cpp
===================================================================
--- clang/unittests/Format/TokenAnnotatorTest.cpp
+++ clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -175,6 +175,48 @@
   ASSERT_EQ(Tokens.size(), 17u) << Tokens;
   EXPECT_TOKEN(Tokens[9], tok::ampamp, TT_PointerOrReference);
   EXPECT_TOKEN(Tokens[12], tok::ampamp, TT_PointerOrReference);
+
+  Tokens = annotate("val1 & val2;");
+  ASSERT_EQ(Tokens.size(), 5u) << Tokens;
+  EXPECT_TOKEN(Tokens[1], tok::amp, TT_BinaryOperator);
+
+  Tokens = annotate("val1 & val2.member;");
+  ASSERT_EQ(Tokens.size(), 7u) << Tokens;
+  EXPECT_TOKEN(Tokens[1], tok::amp, TT_BinaryOperator);
+
+  Tokens = annotate("val1 & val2 & val3;");
+  ASSERT_EQ(Tokens.size(), 7u) << Tokens;
+  EXPECT_TOKEN(Tokens[1], tok::amp, TT_BinaryOperator);
+  EXPECT_TOKEN(Tokens[3], tok::amp, TT_BinaryOperator);
+
+  Tokens = annotate("val1 & val2 // comment\n"
+                    "     & val3;");
+  ASSERT_EQ(Tokens.size(), 8u) << Tokens;
+  EXPECT_TOKEN(Tokens[1], tok::amp, TT_BinaryOperator);
+  EXPECT_TOKEN(Tokens[4], tok::amp, TT_BinaryOperator);
+
+  Tokens =
+      annotate("val1 & val2.member & val3.member() & val4 & val5->member;");
+  ASSERT_EQ(Tokens.size(), 19u) << Tokens;
+  EXPECT_TOKEN(Tokens[1], tok::amp, TT_BinaryOperator);
+  EXPECT_TOKEN(Tokens[5], tok::amp, TT_BinaryOperator);
+  EXPECT_TOKEN(Tokens[11], tok::amp, TT_BinaryOperator);
+  EXPECT_TOKEN(Tokens[13], tok::amp, TT_BinaryOperator);
+
+  Tokens = annotate("class c {\n"
+                    "  void func(type &a) { a & member; }\n"
+                    "  anotherType &member;\n"
+                    "}");
+  ASSERT_EQ(Tokens.size(), 22u) << Tokens;
+  EXPECT_TOKEN(Tokens[7], tok::amp, TT_PointerOrReference);
+  EXPECT_TOKEN(Tokens[12], tok::amp, TT_BinaryOperator);
+  EXPECT_TOKEN(Tokens[17], tok::amp, TT_PointerOrReference);
+
+  Tokens = annotate("struct S {\n"
+                    "  auto Mem = C & D;\n"
+                    "}");
+  ASSERT_EQ(Tokens.size(), 12u) << Tokens;
+  EXPECT_TOKEN(Tokens[7], tok::amp, TT_BinaryOperator);
 }
 
 TEST_F(TokenAnnotatorTest, UnderstandsUsesOfPlusAndMinus) {