[LowCal]

Not sure about Mexico’s Hacienda reporting your income earned in Mexico to the IRS but @Churro is partially correct about the 10K USD bank balances. Here is a better explanation I found:

“For expats living here (in Mexico), say you move US$100,000 into a certificate of deposit into a bank in Mexico because you are getting a better interest rate down here. Your Mexican bank will have to report the interest on that account to the IRS. It is important to report that interest on your tax return on Schedule B. If your highest balance is under US$10,000 on any day of the year, it is strictly a check-the-box. You just go to Schedule B, check the box that says I have a foreign bank account and put your interest income on that schedule. If it is over US$10,000, then you have to file what is called the Foreign Bank Account Report (FBAR). It does not go on your return, but it is a separate document that is filed with the U.S. Treasury Department. It must be filed on an annual basis if you have more than US$10,000 in a foreign bank account, or all foreign bank accounts combined.”

https://www.bnctax.com/blog/do-expats-in-mexico-have-to-pay-u-s-taxes/