The European Union (EU) introduced a special transitional semi-subsistence measure to promote the smallest agricultural producers, so-called semi-subsistence farm households (SFHs) in the enlargement process. An outlook on the future of SFHs requires comprehensive and reliable information on the phenomenon and the impact of policy measures on their development. Therefore, a survey using a standardised questionnaire was conducted in Poland (175 households), Romania (185 households), and Bulgaria (184 households) from July to September 2007. In a first step, four major types of SFHs could be identified by means of cluster analysis: (i) rural diversifiers, (ii) rural pensioners, (iii) farmers, and (iv) rural newcomers. In a second step, a multiobjective linear programming household model was designed to simulate the impact of policy measures and various household strategies on the future viability of the SFHs. Results show that the most preferable combination of strategies for rural diversifiers and rural newcomers is starting a non-farm self-employed activity and developing their farms. Farmers will advance best when they focus on developing their farms only, whereas rural pensioners will mainly remain or become unviable.