Background: Empirical evidence is growing for the fact that societal conditions are major causes of differences in health across individuals and societies. A positive correlation between socioeconomic status and health outcomes is documented in countries with various welfare arrangements, level of social trust, and health policies. We investigated how the health gradient was affected by healthcare intervention. Methods: Self-reported data on health status after exposure to healthcare intervention was collected by means of a postal survey (2009) to all members of the Norwegian Breast Cancer Association. Response rate was 62 percent. 1666 women aged 40-69 was included in the analysis. In order to create a counterfactual framework, we used propensity score analysis to match each observation in the treatment sample with an observation in a non-treatment sample. The observations were classified into high and low socioeconomic status groups based on information on education and labor market affiliation. Results and conclusion: A social gradient in self-rated health was found. Experience of breast cancer and treatment was shown to have a moderating effect on the gradient. While high-status women on average reported a 0.63 points reduction in health after breast cancer treatment, the corresponding reduction for low status women was 0.32 points. These results lend some support to the hypothesis that individuals from lower status groups may benefit from healthcare more than others due to effects of information and support.