Look inside the additional-methods.js
file for the various zip code rules. You can copy and tweak them as you see fit.
jQuery.validator.addMethod("ziprange", function(value, element) {
return this.optional(element) || /^90[2-5]\d\{2\}-\d{4}$/.test(value);
}, "Your ZIP-code must be in the range 902xx-xxxx to 905-xx-xxxx");
jQuery.validator.addMethod("zipcodeUS", function(value, element) {
return this.optional(element) || /\d{5}-\d{4}$|^\d{5}$/.test(value);
}, "The specified US ZIP Code is invalid");