Purpose To explain the needs for rehabilitation of patients with bone sarcoma before and after surgical resection and reconstruction with megaprosthesis. Materials and methods We performed a qualitative study following constructivist grounded theory principles. We purposefully recruited rich cases. Data were collected using semi-structured interviews and analyzed with grounded theory data-analysis. Initial, focused, and theoretical coding were first performed independently by two authors and followed by discussion in consensus meetings with all authors. Ultimately, a conceptual model was created. Results Thirteen participants were interviewed between March and May 2023. Seven theoretical codes were found. The first is the need to achieve a new normal, being able to function with their medical history and megaprosthesis in a new normal life. Two key values patients needed were being understood and being prepared. Four important conditions that patients needed were: optimal conditions for rehabilitation, a trustworthy physical therapist, a clear closure from rehabilitation, and access to expertise in the hospital. The core category was achieving a new normal. Conclusions Patients with bone sarcoma need rehabilitation to achieve a new normal life. With the understanding of needs regarding rehabilitation now gained, the care for patients with bone sarcoma should be better tailored.