The purpose of this project is to identify effective strategies to assist survivors of childhood and young adult cancers (diagnosed between birth and age 39) who have not returned for follow-up cancer care for 3 or more years, to reengage with the health care system. The investigator will evaluate the effect of a novel, bidirectional conversational agent ("Penny"), compared to usual care, to assist patients with scheduling appointments, lab work as well as scans and specialty appointments as needed.

To achieve this, the investigator will use a two-arm randomized controlled trial to explore how multilevel factors impact the acceptability and effectiveness of this strategy by collecting qualitative and quantitative data from patients. Penny is a conversational agent ("chatbot") that engages patients in real time via text messaging, allowing for bidirectional communication and motivational cues to promote adherence. The chatbot will assist patients who have not been see for cancer follow-up care, with scheduling follow-up appointments, labs, scans, specialty appointments, and monitor compliance with the appointments made.

Inclusion Criteria:

• Adult patient (age > 18 years), male or female, diagnosed with cancer as a child or as a young adult, between birth and 39 years of age
• Patient possession of a mobile device that can receive SMS texts
• Ability to respond to questions and engage with "Penny" in English
• Ability to provide informed consent to participate in the study
• Approval of the patient's oncology care team for the patient to be involved in the study

Exclusion Criteria:

• Anyone who does not meet the inclusion criteria
• Patients with a history of thyroid cancer or skin cancers