.NET String.Format() to add commas in thousands place for a number

I want to add a comma in the thousands place for a number.

Would String.Format() be the correct path to take? What format would I use?

String.Format("{0:n}", 1234);  // Output: 1,234.00
String.Format("{0:n0}", 9876); // No digits after the decimal point. Output: 9,876