This study says 3k+ for the under 18 crowd. (edits: possibly inclusive of 18)
This cohort study examines trends in inpatient and outpatient gender-affirming surgical procedures in the US and explores the temporal trends in the types of procedures across age groups.
jamanetwork.com
Abstract
Importance While changes in federal and state laws mandating coverage of gender-affirming surgery (GAS) may have led to an increase in the number of annual cases, comprehensive data describing trends in both inpatient and outpatient procedures are limited.
Objective To examine trends in inpatient and outpatient GAS procedures in the US and to explore the temporal trends in the types of GAS performed across age groups.
Design, Setting, and Participants This cohort study includes data from 2016 to 2020 in the Nationwide Ambulatory Surgery Sample and the National Inpatient Sample. Patients with diagnosis codes for gender identity disorder, transsexualism, or a personal history of sex reassignment were identified, and the performance of GAS, including breast and chest procedures, genital reconstructive procedures, and other facial and cosmetic surgical procedures, were identified.
Main Outcome Measures Weighted estimates of the annual number of inpatient and outpatient procedures performed and the distribution of each class of procedure overall and by age were analyzed.
Results A total of 48 019 patients who underwent GAS were identified, including 25 099 (52.3%) who were aged 19 to 30 years. The most common procedures were breast and chest procedures, which occurred in 27 187 patients (56.6%), followed by genital reconstruction (16 872 [35.1%]) and other facial and cosmetic procedures (6669 [13.9%]). The absolute number of GAS procedures rose from 4552 in 2016 to a peak of 13 011 in 2019 and then declined slightly to 12 818 in 2020. Overall, 25 099 patients (52.3%) were aged 19 to 30 years, 10 476 (21.8%) were aged 31 to 40,
and 3678 (7.7%) were aged12 to 18 years. When stratified by the type of procedure performed, breast and chest procedures made up a greater percentage of the surgical interventions in younger patients, while genital surgical procedures were greater in older patients.
Conclusions and Relevance Performance of GAS has increased substantially in the US. Breast and chest surgery was the most common group of procedures performed. The number of genital surgical procedures performed increased with increasing age.