@FanDesEchecs, I might be wrong, but isn't NM only for the U.S.A?
If you can get 'NM' in other countries than he probably dropped his rating, but you don't get your title taken away...
There are several chess federations with NM titles. USCF and ECF are two.
See
en.wikipedia.org/wiki/Chess_title#National_titlesWhy only Patrons posting?
There are several tournaments that give you the NM title according your performance. I got mine at the national championship.