South Korea has tightened requirements for foreign National Pension enrollees seeking lump-sum retroactive contributions after concerns that short-term workers were using back payments to reach the 120-month threshold for lifetime pension benefits. Effective from the 31st of the previous month, the revised guidelines replace registered residency with actual domestic residency and require immigration records alongside marital-status documents. The National Pension Service will count a month only when the applicant was physically in South Korea for at least 15 days. The government is also pursuing legislation to extend the reciprocity principle to retroactive contributions, limiting eligibility to nationals of countries that offer South Korean citizens the same right. It plans to verify the survival status of overseas pension recipients twice a year, expand cross-border death-data exchanges and review other potential gaps, including dependent family pensions. The controversy has particularly involved ethnic Koreans with Chinese citizenship. National Pension Service Chairman Kim Sung-joo previously argued that contribution history, rather than nationality, should guide restrictions, but now said post-payment management would be strengthened.