Background: Whilemelanoma incidence continues to rise in the United States, trends in children and AYA groups are poorly defined.Understanding the burden in these groups is critical in developing effective prevention strategies to ↓ risk. Methods: Data from 9 registries that have contributed to the SEER program since 1973 were used to assess descriptive epidemiology & time-trends in incidence & overall survival (OS) of melanoma in children (0-14 yrs) & AYA (15-39 yrs) from 1973-2011. 4 time quartiles (1973-80, 1981-90, 1991-2000 & 2001-11) were used. OS was compared using univariate & multivariate proportional hazards methods controlling for age, gender, race, ethnicity, stage, site & time period of diagnosis. Analyses were done using SAS v9.4. Results: 35,726 cases of melanoma in < 40 yrs old were reported from 1973-2011; median age 32 yrs; 98.9% cases in AYA. There were 13,616 males (38%) & 22,110 females (62%) with ↑ incidence in both genders over time (p < 0.001). The incidence rate per 100,000 ↑ from 13.26 to 46.79 (p < 0.001); similar significant trends were noted in both age groups across time quartiles (children: 0.45 → 1.51; AYA 22.28 →74.36; all p < 0.001). An ↑ female/male incidence rate ratio over time was noted; females comprised 57% of cases from 1973-80 but 65.2% of cases from 2001-11 (p < 0.001). The incidence was significantly higher in whites (94.8%) than other races. Most cases were cutaneous (98.6%) & localized; the incidence of in-situ melanoma rose from 4.1% to 30.4% over time (p < 0.001). OS has ↑ over all time quartiles (ref 1973-80; HR = 0.86, 0.65, 0.38; all p < 0.001) with 5 & 10-yr OS of 0.93 and 0.90 respectively. No difference in OS was seen between children & AYA (HR = 0.79; 95% CI, 0.6, 1.05; p = 0.1) or between blacks & whites (HR = 1.02; 0.70, 1.49; p = 0.907). Ocular melanoma was associated with ↓ OS (HR = 1.75; 1.48, 2.08; p = < 0.001). Conclusions: Since 1973, the incidence of melanoma in children and AYA has increased by 253% with white female young adults at particular risk. There is a trend in diagnosis at earlier disease stage. Potential causes must be explored to devise intervention strategies.