Hi,
I was an international graduate student who arrived in 2001 and had no US income for that year since I wasn't working. I however wasn't well versed with tax law and did not file form 8843. Should I file this at this late moment? What are the penalties? I have filed this and other forms regularly since then.
Thanks

Effectively, there are NO penalties.

File it; better late than never.

You file Form 8843 if you are an exempt individual. For example, everyone is exempt for 5 years on F1/OPT, and every one on J1 is exempt for 2-years.