Get your taxes done using TurboTax

Here's another question for you all. I live in Brazil and will now only pay into the Brazilian Social Security system. Our income in very low, under USD20,000.00 . In 2018, we paid no income tax and only paid SS self-employed tax. Now that we will be only paying into the Brazilian SS, am I correct in assuming we won't owe anything to the IRS? The reason I am asking is that I used to be very careful with home office expenses, documenting everything to be able to pay the least in SS tax. But now it doesn't seem to matter. So I am wondering if it's OK to just not do such a detailed report of all our business expenses because it won't make any difference in what we owe. 

Sorry this is not so clear. Any ideas would be helpful.