MEPS. If it is not listed on your entry examination and you never were seen by a doctor for it before. Speaking from experience. 10-20 degrees curvature. 40% disability. Honorable discharge. Finished enlistment.
EPTS (Existing prior to service) normally falls within the first 180 days of enlistment. Not sure if it applies to uniformed personnel past that date. You should probably ask JAG or medical doctor for more information.