Background: Oncologist-led follow-up after breast cancer (BC) is increasingly replaced with less intensive follow-up based on higher self-management, which may overburden the less resourceful patients. We examined whether socioeconomic factors measured recently after the implementation of a new follow-up program for BC patients were associated with health-related quality of life (HRQoL) and self-management 12 months later. Methodology: Between January and August 2017, we invited 1773 patients in Region Zealand, Denmark, to participate in baseline and 12 months follow-up questionnaires. The patients had surgery for low- and intermediate risk BC 1–10 years prior to the survey, and they had recently been allocated to the new follow-up program of either patient-initiated follow-up, or in-person or telephone follow-up with a nurse, based on patients’ preferences. We examined associations between socioeconomic factors (education and cohabitation) at baseline and two outcomes: HRQoL (EORTC QLQ-C30 and QLQ-BR23) and self-management factors (health care provider, confidence in follow-up, contact at symptoms of concern, and self-efficacy) at 12 months follow-up. Sensitivity analyses were performed according to time since diagnosis (≤ 5 > 5 years). Furthermore, we investigated whether treatment and self-management factors modified the associations. Results: A total of 987 patients were included in the analyses. We found no statistically significant associations between socioeconomic factors and HRQoL, except in patients ≤ 5 years from diagnosis. For self-management patients with short education were more likely to report that they had not experience relevant symptoms of concern compared to those with medium/long education (OR 1.75 95% CI: 1.04; 2.95). We found no clear patterns indicating that treatment or self-management factors modified the associations between socioeconomics’ and HRQoL. Conclusion: Overall socioeconomic factors did not influence HRQoL and self-management factors except for experiencing and reporting relevant symptoms of concern. Socioeconomic factors may, however, influence HRQoL in patients within five years of diagnosis.