I am a US citizen. Based on my past experience, I cannot claim my parents as dependents if they live in China. However, US law does allow citizens of Canada and Mexico to be claimed as dependents. I spent thousands of $s on my mother's medical bills. I felt I am beding descriminated based on my country of origin. Do I have a case against IRS?

This is REALLY a legal question, best posted on the LAW forum.

That said, I doubt that you have a case. The provision that allows citizens of Mexico and Canada to claim the parents as dependents on their U.S. tax returns are parts of the tax treaties between the U.S. and these countries. And the provision goes BOTH ways (i.e. a U.S. citizen can claim HIS parents on dependents on their Canadian or Mexican tax returns as well).

This is REALLY a legal question, best posted on the LAW forum.

That said, I doubt that you have a case. The provision that allows citizens of Mexico and Canada to claim the parents as dependents on their U.S. tax returns are parts of the tax treaties between the U.S. and these countries. And the provision goes BOTH ways (i.e., a U.S. citizen can claim HIS parents on dependents on their Canadian or Mexican tax returns as well).

There is limit to international treaties in my opinion. If Britain and US signed a treaty giving US citizen who has a British parent two votes and a British citizen who has a US paraent two votes, the court will reject that treaty (law). Why is taxation any different from voting right?

If your parents are U.S. citizen or resident, you can claim them even when they live in China.

MukatA has a point. I mis-read your question.

Mexicans and Canadians can claim their spouses and children as dependents even though they are still in Mexico and Canada. However, they CANNOT claim their parents if those parents are NOT residents or citizens of the U.S.

So you have no case! The issue is not one of treaty, but rather one of U.S. tax law, and, in this case, the U.S. tax law treats your case no different than it treats a Mexican or Canadian citizen.