diff --git a/api/next/53202.txt b/api/next/53202.txt
new file mode 100644
index 0000000000..8dadbfb4e5
--- /dev/null
+++ b/api/next/53202.txt
@@ -0,0 +1,2 @@
+pkg go/ast, type File struct, FileEnd token.Pos #53202
+pkg go/ast, type File struct, FileStart token.Pos #53202
diff --git a/src/go/ast/ast.go b/src/go/ast/ast.go
index 8d138fc72a..9baf72f40f 100644
--- a/src/go/ast/ast.go
+++ b/src/go/ast/ast.go
@@ -1036,17 +1036,24 @@ func (*FuncDecl) declNode() {}
 // and Comment comments directly associated with nodes, the remaining comments
 // are "free-floating" (see also issues #18593, #20744).
 type File struct {
-	Doc        *CommentGroup   // associated documentation; or nil
-	Package    token.Pos       // position of "package" keyword
-	Name       *Ident          // package name
-	Decls      []Decl          // top-level declarations; or nil
-	Scope      *Scope          // package scope (this file only)
-	Imports    []*ImportSpec   // imports in this file
-	Unresolved []*Ident        // unresolved identifiers in this file
-	Comments   []*CommentGroup // list of all comments in the source file
+	Doc     *CommentGroup // associated documentation; or nil
+	Package token.Pos     // position of "package" keyword
+	Name    *Ident        // package name
+	Decls   []Decl        // top-level declarations; or nil
+
+	FileStart, FileEnd token.Pos       // start and end of entire file
+	Scope              *Scope          // package scope (this file only)
+	Imports            []*ImportSpec   // imports in this file
+	Unresolved         []*Ident        // unresolved identifiers in this file
+	Comments           []*CommentGroup // list of all comments in the source file
 }
 
+// Pos returns the position of the package declaration.
+// (Use FileStart for the start of the entire file.)
 func (f *File) Pos() token.Pos { return f.Package }
+
+// End returns the end of the last declaration in the file.
+// (Use FileEnd for the end of the entire file.)
 func (f *File) End() token.Pos {
 	if n := len(f.Decls); n > 0 {
 		return f.Decls[n-1].End()
diff --git a/src/go/ast/example_test.go b/src/go/ast/example_test.go
index 67860ce922..c6904be6e5 100644
--- a/src/go/ast/example_test.go
+++ b/src/go/ast/example_test.go
@@ -126,15 +126,17 @@ func main() {
 	//     47  .  .  .  }
 	//     48  .  .  }
 	//     49  .  }
-	//     50  .  Scope: *ast.Scope {
-	//     51  .  .  Objects: map[string]*ast.Object (len = 1) {
-	//     52  .  .  .  "main": *(obj @ 11)
-	//     53  .  .  }
-	//     54  .  }
-	//     55  .  Unresolved: []*ast.Ident (len = 1) {
-	//     56  .  .  0: *(obj @ 29)
-	//     57  .  }
-	//     58  }
+	//     50  .  FileStart: 1:1
+	//     51  .  FileEnd: 5:3
+	//     52  .  Scope: *ast.Scope {
+	//     53  .  .  Objects: map[string]*ast.Object (len = 1) {
+	//     54  .  .  .  "main": *(obj @ 11)
+	//     55  .  .  }
+	//     56  .  }
+	//     57  .  Unresolved: []*ast.Ident (len = 1) {
+	//     58  .  .  0: *(obj @ 29)
+	//     59  .  }
+	//     60  }
 }
 
 // This example illustrates how to remove a variable declaration
diff --git a/src/go/ast/filter.go b/src/go/ast/filter.go
index 2fc73c4b99..7d2a11e475 100644
--- a/src/go/ast/filter.go
+++ b/src/go/ast/filter.go
@@ -340,6 +340,7 @@ func MergePackageFiles(pkg *Package, mode MergeMode) *File {
 	ncomments := 0
 	ndecls := 0
 	filenames := make([]string, len(pkg.Files))
+	var minPos, maxPos token.Pos
 	i := 0
 	for filename, f := range pkg.Files {
 		filenames[i] = filename
@@ -349,6 +350,12 @@ func MergePackageFiles(pkg *Package, mode MergeMode) *File {
 		}
 		ncomments += len(f.Comments)
 		ndecls += len(f.Decls)
+		if i == 0 || f.FileStart < minPos {
+			minPos = f.FileStart
+		}
+		if i == 0 || f.FileEnd > maxPos {
+			maxPos = f.FileEnd
+		}
 	}
 	sort.Strings(filenames)
 
@@ -484,5 +491,5 @@ func MergePackageFiles(pkg *Package, mode MergeMode) *File {
 	}
 
 	// TODO(gri) need to compute unresolved identifiers!
-	return &File{doc, pos, NewIdent(pkg.Name), decls, pkg.Scope, imports, nil, comments}
+	return &File{doc, pos, NewIdent(pkg.Name), decls, minPos, maxPos, pkg.Scope, imports, nil, comments}
 }
diff --git a/src/go/parser/parser.go b/src/go/parser/parser.go
index 5ee53fc81e..89ed0e433f 100644
--- a/src/go/parser/parser.go
+++ b/src/go/parser/parser.go
@@ -2836,12 +2836,14 @@ func (p *parser) parseFile() *ast.File {
 	}
 
 	f := &ast.File{
-		Doc:      doc,
-		Package:  pos,
-		Name:     ident,
-		Decls:    decls,
-		Imports:  p.imports,
-		Comments: p.comments,
+		Doc:       doc,
+		Package:   pos,
+		Name:      ident,
+		Decls:     decls,
+		FileStart: token.Pos(p.file.Base()),
+		FileEnd:   token.Pos(p.file.Base() + p.file.Size()),
+		Imports:   p.imports,
+		Comments:  p.comments,
 	}
 	var declErr func(token.Pos, string)
 	if p.mode&DeclarationErrors != 0 {
diff --git a/src/go/parser/parser_test.go b/src/go/parser/parser_test.go
index 6d559e231c..153562df75 100644
--- a/src/go/parser/parser_test.go
+++ b/src/go/parser/parser_test.go
@@ -488,6 +488,34 @@ func TestIssue9979(t *testing.T) {
 	}
 }
 
+func TestFileStartEndPos(t *testing.T) {
+	const src = `// Copyright
+
+//+build tag
+
+// Package p doc comment.
+package p
+
+var lastDecl int
+
+/* end of file */
+`
+	fset := token.NewFileSet()
+	f, err := ParseFile(fset, "file.go", src, 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// File{Start,End} spans the entire file, not just the declarations.
+	if got, want := fset.Position(f.FileStart).String(), "file.go:1:1"; got != want {
+		t.Errorf("for File.FileStart, got %s, want %s", got, want)
+	}
+	// The end position is the newline at the end of the /* end of file */ line.
+	if got, want := fset.Position(f.FileEnd).String(), "file.go:10:19"; got != want {
+		t.Errorf("for File.FileEnd, got %s, want %s", got, want)
+	}
+}
+
 // TestIncompleteSelection ensures that an incomplete selector
 // expression is parsed as a (blank) *ast.SelectorExpr, not a
 // *ast.BadExpr.