Insurance rates for crop yield protection programs have traditionally been calcu lated from county average yie lds. Where grower acreages and yields are not homogeneous, this approach leads to higher premiums and payouts and greater incidence of adverse selection . With individual grower data a production weighted rate premium calcu lation method ca~ be used which avoids these problems . Furthermore, the definition of rate classes is not constrained to county boundaries. The additional complication of technical change is addressed and one solution is provided. Results are presented for the cranberry industry.