Good suggestion for the O/P
@Ste****
, (y)
Unfortunately only a person over 50 could qualify for the year-long, multi-entry Non-Immigrant Type O-A (Long Stay) )visa :/
His wife could apply at the same time for a 90 day single entry Non-Immigrant Type O visa as the spouse of someone on an O-A visa and then she could apply for a yearly extension which matches her husbands admitted until stamp at the immigration office for 1900baht. After that if she's going to exit/re-enter the country she'd hafta buy a re-entry permit.
OR she could check and see if the consulate will sell her an year-long, multi-entry Non-Immigrant Type O visa (which would mean every 90 days she'd need to border bounce <-go to the border, stamp out of thailand, stamp in&out of another country, then back into thailand to get a 90 day stamp.