Many countries have retirement savings accounts that function similarly to a US 401(k) — tax-deferred contributions and employer matching — but the IRS only recognizes their tax-advantaged status if a specific provision in a US tax treaty covers them. Countries with treaty provisions that provide some US recognition for their pension systems include the UK (workplace pensions), Canada (RRSP), Germany (statutory and some supplemental pensions), Australia (Super under certain analyses), and Japan (statutory pension). For countries without a comprehensive US tax treaty — like the UAE, Singapore, or most of Southeast Asia — contributions to local retirement plans are typically treated as current taxable compensation on the US return, and earnings inside the plan may also be currently taxable. The practical advice for US expats: keep contributing to your employer's plan to get the match and local tax benefits, but plan for the US tax cost of the contributions rather than assuming they're deferred. In high-treaty countries, work with a specialist to make the proper elections to preserve the deferral.