diff --git a/internal/lsp/analysis/fillstruct/fillstruct.go b/internal/lsp/analysis/fillstruct/fillstruct.go
index c760b69..36a63a1 100644
--- a/internal/lsp/analysis/fillstruct/fillstruct.go
+++ b/internal/lsp/analysis/fillstruct/fillstruct.go
@@ -49,11 +49,6 @@
 		}
 		expr := n.(*ast.CompositeLit)
 
-		// TODO: Handle partially-filled structs as well.
-		if len(expr.Elts) != 0 {
-			return
-		}
-
 		var file *ast.File
 		for _, f := range pass.Files {
 			if f.Pos() <= expr.Pos() && expr.Pos() <= f.End() {
@@ -90,10 +85,10 @@
 		if fieldCount == 0 || fieldCount == len(expr.Elts) {
 			return
 		}
+
 		var fillable bool
 		for i := 0; i < fieldCount; i++ {
 			field := obj.Field(i)
-
 			// Ignore fields that are not accessible in the current package.
 			if field.Pkg() != nil && field.Pkg() != pass.Pkg && !field.Exported() {
 				continue
@@ -137,6 +132,7 @@
 			break
 		}
 	}
+
 	if info == nil {
 		return nil, fmt.Errorf("nil types.Info")
 	}
@@ -161,6 +157,17 @@
 	}
 	fieldCount := obj.NumFields()
 
+	// Check which types have already been filled in. (we only want to fill in
+	// the unfilled types, or else we'll blat user-supplied details)
+	prefilledTypes := map[string]ast.Expr{}
+	for _, e := range expr.Elts {
+		if kv, ok := e.(*ast.KeyValueExpr); ok {
+			if key, ok := kv.Key.(*ast.Ident); ok {
+				prefilledTypes[key.Name] = kv.Value
+			}
+		}
+	}
+
 	// Use a new fileset to build up a token.File for the new composite
 	// literal. We need one line for foo{, one line for }, and one line for
 	// each field we're going to set. format.Node only cares about line
@@ -186,21 +193,6 @@
 		if fieldTyp == nil {
 			continue
 		}
-		idents, ok := matches[fieldTyp]
-		if !ok {
-			return nil, fmt.Errorf("invalid struct field type: %v", fieldTyp)
-		}
-
-		// Find the identifer whose name is most similar to the name of the field's key.
-		// If we do not find any identifer that matches the pattern, generate a new value.
-		// NOTE: We currently match on the name of the field key rather than the field type.
-		value := analysisinternal.FindBestMatch(obj.Field(i).Name(), idents)
-		if value == nil {
-			value = populateValue(fset, file, pkg, fieldTyp)
-		}
-		if value == nil {
-			return nil, nil
-		}
 
 		tok.AddLine(line - 1) // add 1 byte per line
 		if line > tok.LineCount() {
@@ -214,7 +206,27 @@
 				Name:    obj.Field(i).Name(),
 			},
 			Colon: pos,
-			Value: value,
+		}
+		if expr, ok := prefilledTypes[obj.Field(i).Name()]; ok {
+			kv.Value = expr
+		} else {
+			idents, ok := matches[fieldTyp]
+			if !ok {
+				return nil, fmt.Errorf("invalid struct field type: %v", fieldTyp)
+			}
+
+			// Find the identifer whose name is most similar to the name of the field's key.
+			// If we do not find any identifer that matches the pattern, generate a new value.
+			// NOTE: We currently match on the name of the field key rather than the field type.
+			value := analysisinternal.FindBestMatch(obj.Field(i).Name(), idents)
+			if value == nil {
+				value = populateValue(fset, file, pkg, fieldTyp)
+			}
+			if value == nil {
+				return nil, nil
+			}
+
+			kv.Value = value
 		}
 		elts = append(elts, kv)
 		line++
@@ -251,31 +263,51 @@
 	index := bytes.Index(firstLine, trimmed)
 	whitespace := firstLine[:index]
 
-	var newExpr bytes.Buffer
-	if err := format.Node(&newExpr, fakeFset, cl); err != nil {
-		return nil, fmt.Errorf("failed to format %s: %v", cl.Type, err)
+	// First pass through the formatter: turn the expr into a string.
+	var formatBuf bytes.Buffer
+	if err := format.Node(&formatBuf, fakeFset, cl); err != nil {
+		return nil, fmt.Errorf("failed to run first format on:\n%s\ngot err: %v", cl.Type, err)
 	}
-	split = bytes.Split(newExpr.Bytes(), []byte("\n"))
+	sug := indent(formatBuf.Bytes(), whitespace)
+
+	if len(prefilledTypes) > 0 {
+		// Attempt a second pass through the formatter to line up columns.
+		sourced, err := format.Source(sug)
+		if err == nil {
+			sug = indent(sourced, whitespace)
+		}
+	}
+
+	return &analysis.SuggestedFix{
+		TextEdits: []analysis.TextEdit{
+			{
+				Pos:     expr.Pos(),
+				End:     expr.End(),
+				NewText: sug,
+			},
+		},
+	}, nil
+}
+
+// indent works line by line through str, indenting (prefixing) each line with
+// ind.
+func indent(str, ind []byte) []byte {
+	split := bytes.Split(str, []byte("\n"))
 	newText := bytes.NewBuffer(nil)
 	for i, s := range split {
+		if len(s) == 0 {
+			continue
+		}
 		// Don't add the extra indentation to the first line.
 		if i != 0 {
-			newText.Write(whitespace)
+			newText.Write(ind)
 		}
 		newText.Write(s)
 		if i < len(split)-1 {
 			newText.WriteByte('\n')
 		}
 	}
-	return &analysis.SuggestedFix{
-		TextEdits: []analysis.TextEdit{
-			{
-				Pos:     expr.Pos(),
-				End:     expr.End(),
-				NewText: newText.Bytes(),
-			},
-		},
-	}, nil
+	return newText.Bytes()
 }
 
 // populateValue constructs an expression to fill the value of a struct field.
diff --git a/internal/lsp/analysis/fillstruct/testdata/src/a/a.go b/internal/lsp/analysis/fillstruct/testdata/src/a/a.go
index b5df1de..f69fe83 100644
--- a/internal/lsp/analysis/fillstruct/testdata/src/a/a.go
+++ b/internal/lsp/analysis/fillstruct/testdata/src/a/a.go
@@ -27,7 +27,7 @@
 
 var _ = twoArgStruct{} // want ""
 
-var _ = twoArgStruct{
+var _ = twoArgStruct{ // want ""
 	bar: "bar",
 }
 
diff --git a/internal/lsp/cmd/test/suggested_fix.go b/internal/lsp/cmd/test/suggested_fix.go
index 965edd4..bf7fb30 100644
--- a/internal/lsp/cmd/test/suggested_fix.go
+++ b/internal/lsp/cmd/test/suggested_fix.go
@@ -12,7 +12,7 @@
 	"golang.org/x/tools/internal/span"
 )
 
-func (r *runner) SuggestedFix(t *testing.T, spn span.Span, actionKinds []string) {
+func (r *runner) SuggestedFix(t *testing.T, spn span.Span, actionKinds []string, expectedActions int) {
 	uri := spn.URI()
 	filename := uri.Filename()
 	args := []string{"fix", "-a", fmt.Sprintf("%s", spn)}
diff --git a/internal/lsp/lsp_test.go b/internal/lsp/lsp_test.go
index f9a3cb2..81d3168 100644
--- a/internal/lsp/lsp_test.go
+++ b/internal/lsp/lsp_test.go
@@ -458,7 +458,7 @@
 	}
 }
 
-func (r *runner) SuggestedFix(t *testing.T, spn span.Span, actionKinds []string) {
+func (r *runner) SuggestedFix(t *testing.T, spn span.Span, actionKinds []string, expectedActions int) {
 	uri := spn.URI()
 	view, err := r.server.session.ViewOf(uri)
 	if err != nil {
@@ -509,10 +509,13 @@
 	if err != nil {
 		t.Fatalf("CodeAction %s failed: %v", spn, err)
 	}
-	if len(actions) != 1 {
+	if len(actions) != expectedActions {
 		// Hack: We assume that we only get one code action per range.
-		// TODO(rstambler): Support multiple code actions per test.
-		t.Fatalf("unexpected number of code actions, want 1, got %v", len(actions))
+		var cmds []string
+		for _, a := range actions {
+			cmds = append(cmds, fmt.Sprintf("%s (%s)", a.Command.Command, a.Title))
+		}
+		t.Fatalf("unexpected number of code actions, want %d, got %d: %v", expectedActions, len(actions), cmds)
 	}
 	action := actions[0]
 	var match bool
@@ -529,7 +532,7 @@
 	if cmd := action.Command; cmd != nil {
 		edits, err := commandToEdits(r.ctx, snapshot, fh, rng, action.Command.Command)
 		if err != nil {
-			t.Fatal(err)
+			t.Fatalf("error converting command %q to edits: %v", action.Command.Command, err)
 		}
 		res, err = applyTextDocumentEdits(r, edits)
 		if err != nil {
@@ -565,7 +568,11 @@
 	if !command.Applies(ctx, snapshot, fh, rng) {
 		return nil, fmt.Errorf("cannot apply %v", command.ID())
 	}
-	return command.SuggestedFix(ctx, snapshot, fh, rng)
+	edits, err := command.SuggestedFix(ctx, snapshot, fh, rng)
+	if err != nil {
+		return nil, fmt.Errorf("error calling command.SuggestedFix: %v", err)
+	}
+	return edits, nil
 }
 
 func (r *runner) FunctionExtraction(t *testing.T, start span.Span, end span.Span) {
diff --git a/internal/lsp/source/source_test.go b/internal/lsp/source/source_test.go
index 2d79960..169e3c3 100644
--- a/internal/lsp/source/source_test.go
+++ b/internal/lsp/source/source_test.go
@@ -923,8 +923,9 @@
 }
 
 // These are pure LSP features, no source level functionality to be tested.
-func (r *runner) Link(t *testing.T, uri span.URI, wantLinks []tests.Link)         {}
-func (r *runner) SuggestedFix(t *testing.T, spn span.Span, actionKinds []string)  {}
+func (r *runner) Link(t *testing.T, uri span.URI, wantLinks []tests.Link) {}
+func (r *runner) SuggestedFix(t *testing.T, spn span.Span, actionKinds []string, expectedActions int) {
+}
 func (r *runner) FunctionExtraction(t *testing.T, start span.Span, end span.Span) {}
 func (r *runner) CodeLens(t *testing.T, uri span.URI, want []protocol.CodeLens)   {}
 
diff --git a/internal/lsp/testdata/fillstruct/fill_struct_partial.go b/internal/lsp/testdata/fillstruct/fill_struct_partial.go
new file mode 100644
index 0000000..97b517d
--- /dev/null
+++ b/internal/lsp/testdata/fillstruct/fill_struct_partial.go
@@ -0,0 +1,24 @@
+package fillstruct
+
+type StructPartialA struct {
+	PrefilledInt int
+	UnfilledInt  int
+	StructPartialB
+}
+
+type StructPartialB struct {
+	PrefilledInt int
+	UnfilledInt  int
+}
+
+func fill() {
+	a := StructPartialA{
+		PrefilledInt: 5,
+	} //@suggestedfix("}", "refactor.rewrite")
+	b := StructPartialB{
+		/* this comment should disappear */
+		PrefilledInt: 7, // This comment should be blown away.
+		/* As should
+		this one */
+	} //@suggestedfix("}", "refactor.rewrite")
+}
diff --git a/internal/lsp/testdata/fillstruct/fill_struct_partial.go.golden b/internal/lsp/testdata/fillstruct/fill_struct_partial.go.golden
new file mode 100644
index 0000000..2d063c1
--- /dev/null
+++ b/internal/lsp/testdata/fillstruct/fill_struct_partial.go.golden
@@ -0,0 +1,52 @@
+-- suggestedfix_fill_struct_partial_17_2 --
+package fillstruct
+
+type StructPartialA struct {
+	PrefilledInt int
+	UnfilledInt  int
+	StructPartialB
+}
+
+type StructPartialB struct {
+	PrefilledInt int
+	UnfilledInt  int
+}
+
+func fill() {
+	a := StructPartialA{
+		PrefilledInt:   5,
+		UnfilledInt:    0,
+		StructPartialB: StructPartialB{},
+	} //@suggestedfix("}", "refactor.rewrite")
+	b := StructPartialB{
+		/* this comment should disappear */
+		PrefilledInt: 7, // This comment should be blown away.
+		/* As should
+		this one */
+	} //@suggestedfix("}", "refactor.rewrite")
+}
+
+-- suggestedfix_fill_struct_partial_23_2 --
+package fillstruct
+
+type StructPartialA struct {
+	PrefilledInt int
+	UnfilledInt  int
+	StructPartialB
+}
+
+type StructPartialB struct {
+	PrefilledInt int
+	UnfilledInt  int
+}
+
+func fill() {
+	a := StructPartialA{
+		PrefilledInt: 5,
+	} //@suggestedfix("}", "refactor.rewrite")
+	b := StructPartialB{
+		PrefilledInt: 7,
+		UnfilledInt:  0,
+	} //@suggestedfix("}", "refactor.rewrite")
+}
+
diff --git a/internal/lsp/testdata/summary.txt.golden b/internal/lsp/testdata/summary.txt.golden
index a6aa546..12324fa 100644
--- a/internal/lsp/testdata/summary.txt.golden
+++ b/internal/lsp/testdata/summary.txt.golden
@@ -13,7 +13,7 @@
 FormatCount = 6
 ImportCount = 8
 SemanticTokenCount = 3
-SuggestedFixCount = 38
+SuggestedFixCount = 40
 FunctionExtractionCount = 12
 DefinitionsCount = 64
 TypeDefinitionsCount = 2
diff --git a/internal/lsp/tests/tests.go b/internal/lsp/tests/tests.go
index 33c8625..7eaf9ac 100644
--- a/internal/lsp/tests/tests.go
+++ b/internal/lsp/tests/tests.go
@@ -134,7 +134,7 @@
 	Format(*testing.T, span.Span)
 	Import(*testing.T, span.Span)
 	SemanticTokens(*testing.T, span.Span)
-	SuggestedFix(*testing.T, span.Span, []string)
+	SuggestedFix(*testing.T, span.Span, []string, int)
 	FunctionExtraction(*testing.T, span.Span, span.Span)
 	Definition(*testing.T, span.Span, Definition)
 	Implementation(*testing.T, span.Span, []span.Span)
@@ -633,7 +633,7 @@
 			}
 			t.Run(SpanName(spn), func(t *testing.T) {
 				t.Helper()
-				tests.SuggestedFix(t, spn, actionKinds)
+				tests.SuggestedFix(t, spn, actionKinds, 1)
 			})
 		}
 	})