You can get TNs good for 1 year or 3, but you can technically renew your TN status as many times as you want. The downside is that TN status is strictly for peo

You can get TNs good for 1 year or 3, but you can technically renew your TN status as many times as you want. The downside is that TN status is strictly for people with "non-immigrant intent" and if a border agent believes you have immigrant intent when requesting a TN or entering America with one, they can revoke it/deny you entry at their discretion. So a 3-year TN is fine, maybe even a second one, but if you've been in the US on a TN after 8 or 9 years you're probably going to get some trouble.