The ban on the commercial cultivation of genetically modified (GM) wheat and maize in Switzerland is expected to remain in force until 2013. Coexistence regulations in Switzerland and their resulting impacts on profitability will then require examination. In this paper we present time and cost calculations for what we consider to be the most critical of these coexistence measures. Coexistence measures and their associated costs, based upon the present structure of Swiss Agriculture, are calculated according to varying degrees of restriction and or technical feasibility. We find that, in spite of the small-scale Swiss farm structure, the costs for the coexistence measures are minimal at the farm level. The total costs of implementing coexistence measures per hectare of GM crop plantings range from CHF 58 to CHF 160, this corresponds to roughly 1-3% of total product costs, and are negligible.