GREENWICH, Conn., Jan. 4, 2013 /PRNewswire/ -- Long term homeowners with significantly appreciated properties are in for an unpleasant surprise when they retire. Uncle Sam may take a big chunk of their retirement savings from the sale of their house in many high cost communities, such as New York City, San Francisco, Los Angeles and Honolulu even if the house is relatively modest. If the homeowners refinanced their house they may find they have no retirement savings at all and could even have to come out of pocket to sell their house. Mark Pruner, a Realtor with Prudential Connecticut Realty in Greenwich, Connecticut has done an analysis of all the residential properties in Greenwich potentially subject to the new taxes. "A third to a half of the houses could be subject to the new fiscal cliff and Medicare investment tax increases. Unlike the much publicized $450,000 threshold for higher capital gains taxes in the fiscal cliff bill the new 3.8% Medicare investment tax kicks in at $250,000 for a couple. This is on top of the prior years' 15% capital gains tax so couples are looking at an 18.8% tax, and if their gain exceeds $450,000 then their tax rate will be 23.8%," he said. For people that refinanced they may find that after they pay the mortgage, the capital gains tax, the Medicare investment tax, the Connecticut conveyance tax, real estate commissions and legal fees that the funds that they were depending on for retirement are substantially smaller than they expected and could even be a loss. For people who have retirement bonuses and sell their property in the same year the problem is particularly acute as these onetime income events kick them into much higher tax bracket for that year. The law does provide a $500,000 capital gains exemption for married couples selling their primary residence, but for single people, including widows who stay in their home, the exemption is only $250,000 and the taxes kick in at lower income limits. If the property is not their primary residence then there is no exemption and the full 23.8% rate may apply. The sale of highly appreciated real estate has become hugely complex with the addition this year of the new fiscal cliff tax and the Medicare investment tax and none of the new regulations have been written. Selling a house that a family has owned for years now calls for a trip to the homeowner's tax lawyer or accountant.