Joseph and Dorothy Moller (plaintiffs) were full-time investors, with investment returns constituting almost all of their income since 1965. The Mollers had no employment other than managing their investments. The Mollers maintained a summer home and a winter home, each equipped with a home office in which they both worked 40 hours or more per week to monitor their investments. The Mollers were long-term investors focused on generating interest and dividends, which comprised 98 percent of their investment returns. In 1976 and 1977, the Mollers filed joint income-tax returns, seeking tax deductions for their two home offices. The Mollers’ investment portfolios were valued at $13.5 million in 1976 and $14.5 million in 1977. The federal tax commissioner determined that the expenses associated with the Mollers’ home offices were not valid tax deductions. The Mollers filed suit against the United States government (government) (defendant) in the United States Court of Claims for a tax refund. The court of claims ruled in the Mollers’ favor. The government appealed to the United States Court of Appeals for the Federal Circuit.