Apartment landlords who registered rental properties under the Moon Jae-in administration have launched a National Assembly petition opposing the 2026 tax reform proposal, saying it would retroactively erode benefits promised in exchange for mandatory rental commitments. The proposal would reduce the Long-Term Holding Special Deduction preference from 50% to 30% in 2028, impose a 50% capital gains tax surcharge and eliminate the deduction preference from 2029. It would also abolish the win-win rental program next year and require homeowners to dispose of properties by 2029 to receive tax exclusion benefits. A petition filed by a person identified as Maeng passed the 100-signature threshold for public petitions. Under Assembly rules, petitions reaching 50,000 signatures within 30 days are referred to the relevant standing committee. The Korea Housing Lessors Association estimates that 22,822 Seoul apartments will exit mandatory rental status this year and another 14,861 over the following two years, raising concerns that sales or conversion to owner-occupied homes could worsen the jeonse (large-deposit rental) supply crunch. Landlords and their association argue that practical sale constraints and retroactive tax changes threaten housing stability and public trust.