A growing number of Americans who relocated abroad to capitalize on lower living costs are discovering that returning home has become prohibitively expensive. About 5.5 million U.S. citizens live overseas, with many enjoying lifestyles unattainable on their salaries in the United States.

Nino Trentinella, a freelance educator earning under $40,000 annually, lives comfortably in Tbilisi, Georgia with a housekeeper, daily cabs and regular restaurant meals. Her husband earns a mid-five-figure income. The couple benefits from the foreign earned income exclusion, which exempts the first $130,000 of overseas earnings from U.S. taxation, plus Georgia's 1 percent local tax rate for remote workers.

Video editor Corey O'Flanagan spends roughly $70,000 annually while traveling through Southeast Asia, Southern Europe and the Balkans — a lifestyle that would cost $120,000 in his native Denver. Both expats cite U.S. healthcare costs as a major barrier to returning. Financial advisors warn that many nomads make mistakes with retirement accounts, as those using the foreign earned income exclusion cannot contribute to IRAs.