As a US resident, your parents are required to report their world-wide income. However, Romania and the United States have filed a double taxation treaty that is meant to prevent double taxation of income and property. This includes the taxation of social security income.
If the social security income is their only worldwide income, then it appears that they are not required to file a 2018 tax return because their income does not exceed the filing requirement thresholds:
- Married
Filing Jointly - Under 65 (both spouses) $24,000
- Married
Filing Jointly - 65 or older (one spouse) $25,300
- Married
Filing Jointly - 65 or older (both spouses) $26,600
- Married
filing separately - Any age $5
You can claim your parents as dependents as long as the dependency rules are met:
- You must cover more than half of your parent’s support costs, meaning 51% or more of their support costs must be covered by you. These costs include food, housing or lodging expenses, clothing, and medical services and/or equipment costs.
- They must be related to you biologically, by adoption, or through marriage.
- Your parent’s taxable income cannot be more than $4,050. Non-taxable income, such as Social Security, does not count toward this amount.
- Your parents cannot file a joint tax return.
- You cannot be eligible as a dependent on someone else’s tax return.
- Your parent doesn't have to live with you the entire year.
