e24055 Background: Despite an encouraging 99% five-year survival in patients diagnosed with early-stage melanoma, a higher proportion of fatal melanomas initially present with thin ( < 1mm) rather than thick ( > 4mm) melanoma.¹ Therefore, early-stage melanoma survivorship remains a topic of high interest. We examined a cohort of early-stage melanomas which progressed to stage IV to inform survivorship and risk-stratification approaches in this large, understudied population. Methods: From a retrospective single-center study of 880 consecutive melanoma patients from 2016-2020, we identified new, non- de novo diagnoses of stage IV melanoma which progressed from an initial early-stage (IA-IIA) diagnosis. Descriptive data were collected via chart review on demographics, clinical features, presentation at time of progression, and follow up prior to progression. Results: A total of 50 patients met the inclusion criterion of an initial stage IA-IIA diagnosis with subsequent progression to stage IV melanoma. Primary early stage melanomas were diagnosed an average of 6.1 years prior to metastatic disease progression, with 46% (n = 23) diagnosed within 3 years, 22% (n = 11) between 4-6 years, 12% (n = 6) between 7-10 years, 8% (n = 4) between 10-12 years, and 12% (n = 6) beyond the 12 year mark from their initial early-stage diagnosis. Average age at time of diagnosis was 57.7 (median 60, range 21-68), and 62% (n = 31) were male. The two most common early-stage diagnostic sites were lower extremities (27.5%, n = 14) and back (23.5%, n = 12). The two most common sites of metastatic disease were lung (46%, n = 23) and brain (28%, n = 14). A total of 30% (n = 15) and 34% (n = 17) of this cohort maintained follow up with oncology and dermatology, respectively, prior to their stage IV diagnosis. Symptomatic disease lead to 80% (n = 40) of stage IV diagnoses, while 14% (n = 7) were diagnosed through routine oncologic or dermatologic follow up, and the final 6% were diagnosed incidentally. Conclusions: Early stage melanoma patients who develop stage IV disease exhibit wide ranges in onset of disease progression, thus survivorship plans for this group could include a combination of early provider screening and patient education for later presentations of metastatic disease. Due to relatively common metastatic involvement of the lung and brain, a high suspicion to screen for metastatic disease with symptoms involving these organs may be appropriate.