The post He Sold His ’67 Mustang for $85,000. The IRS Called It a Collectible. Medicare Called It a Salary. appeared first on 24/7 Wall St.. A retiree sells a numbers-matching 1967 Ford Mustang for $85,000, calculates the capital-gains tax, and considers the deal finished. Eighteen months later, a letter from Social Security arrives. His Medicare Part B premium is rising by hundreds of dollars a month. He priced the tax into the sale. Nobody tol…