Can I retire in Bulgaria on US Social Security plus 401(k) withdrawals?

Your plan is very workable — Plovdiv has a growing community of Americans in exactly your situation. Visa: the pensioner D visa route accepts US retirement income; your Social Security award letter is the core document, and 2,400 dollars a month is far above what consulates expect for Bulgaria's living costs. Add a Bulgarian bank account with savings, proof of accommodation (your daughter's address with a notarized declaration works initially, or a rental contract), health insurance, an FBI background check with apostille, and certified translations. D visa first at a US consulate, then the residence permit in Bulgaria, renewed annually, with permanent residence possible after five years. Tax: Bulgaria exempts pensions paid under compulsory state social security schemes, and US Social Security qualifies — Bulgaria takes nothing from it. 401(k) and IRA withdrawals are treated as private pension income and taxed at the flat 10 percent once you are Bulgarian tax resident. As a US citizen you still file US returns on worldwide income regardless; the US-Bulgaria tax treaty and foreign tax credits prevent genuine double taxation, but do use a US expat tax preparer the first year, and remember FBAR reporting once your Bulgarian accounts exceed 10,000 dollars in aggregate. Healthcare: unlike UK retirees, Americans get no S1 arrangement, so budget for private health insurance initially — a few hundred euro a year for basic expat cover, more at 66 with conditions. Once you hold residence you can join the Bulgarian public system by paying health contributions. Details on both tracks: /guides/health-insurance-healthcare-bulgaria, and the visa file at /guides/retiring-in-bulgaria.