Breast cancer treatment is associated with functional sequelae that limit patients in their daily activities or work, impacting their quality of life. This fact becomes more noticeable in the Public System, the tumors are more advanced, leading to more aggressive treatments. Women with low education generally perform menial activities, playing an important role in family income. After cancer treatment, many are unable to carry out their usual activities, having difficulties with their work activities, requiring rehabilitation. These dysfunctions make it difficult or unfeasible to return to work, limiting family income. Knowledge of the Laws, the main sequelae and evaluation methodologies facilitates a more accurate diagnosis of functional conditions, determining the need for rehabilitation. Social Security provides economic support, but to have access to the benefit, a good report is necessary. This, well directed, helps the social security expert and the patients, who are generally so fragile by the disease and the treatment. In this article we discuss the main functional sequelae, how to evaluate them, and how to make a good report to be sent to an expert.