This is a provision in the GOP tax reform bill that was introduced today. (It\'s DOA, but FYI)
Sec. 1407. Limitation on wagering losses.
Current law: Under current law, a taxpayer may claim an itemized deduction for losses from gambling, but only to the extent of gambling winnings. However, taxpayers may claim other deductions connected to gambling that are deductible regardless of gambling winnings.
Provision: Under the provision, all deductions for expenses incurred in carrying out wagering transactions (not just gambling losses) would be limited to the extent of wagering winnings. The provision would be effective for tax years beginning after 2014.
JCT estimate: According to JCT, the provision would increase revenues by $0.1 billion over 2014-2023.