Introduction: Sexual dysfunction affects more than half of cancer survivors and often persists for years, yet most survivors receive neither assessment nor treatment. Although existing reviews describe the burden of sexual morbidity, few translate intervention evidence into a model that oncology services can routinely deliver. Objectives: To appraise the evidence for psychosexual rehabilitation interventions after cancer, organized by intensity of care, and to propose an evidence-based stepped-care model for survivorship practice. Methods: A narrative review was conducted of randomized trials, meta-analyses, systematic reviews and clinical practice guidelines addressing medical, physical, psychological, couple-based, digital and multimodal interventions for sexual problems in adult and young adult cancer survivors. Evidence was evaluated for methodological quality, effect size and applicability, and organized by level of care. Results: Low-intensity measures—including structured discussion, lubricants and moisturizers, topical lidocaine for dyspareunia, and brief clinician training—are inexpensive and supported by randomized or guideline evidence, though often insufficient alone. Evidence for two widely recommended physical interventions is weaker than assumed: scheduled phosphodiesterase-5 inhibitor rehabilitation after prostatectomy shows little benefit over on-demand use or placebo, and routine vaginal dilation during radiotherapy lacks trial support, although dilation after radiotherapy is associated with reduced stenosis. Psychological interventions yield small pooled effects across pelvic cancers but moderate effects in targeted trials, most clearly for therapist-guided internet-based cognitive behavioral therapy in breast cancer survivors, with sustained follow-up benefits. Couple-based telephone interventions demonstrate feasibility and medium-to-large effects in pilot trials, and a clinician-delivered multimodal intervention improved sexual satisfaction and quality of life after stem cell transplantation. Conclusions: Evidence supports matching the intensity of psychosexual care to patient need rather than offering either no care or uniform specialist referral. A five-step stepped-care model can integrate sexual health into routine, scalable survivorship practice. Comparative trials of stepped delivery and of contested physical interventions are now required.