Congress is getting closer to enacting major tax legislation by the end of the year, but first the House and the Senate will have to reconcile key differences in their bills—a task that could prove difficult.

John Gimigliano, principal in charge of the Federal Legislative and Regulatory Services group in KPMG LLP's Washington National Tax practice, joins Talking Tax host Allyson Versprille to discuss the disparities between the two proposals and the implications for the tax reform process.

The resurgence of the alternative minimum tax in the Senate bill has been particularly controversial. Republicans swore they would do away with the tax, but the corporate and individual AMT resurfaced at the last minute as senators needed revenue Dec. 1 to convince GOP holdouts to vote for the bill.

The podcast also features discussion of the approach taken in both bills on pass-throughs, effective dates, and the individual income brackets and tax rates.

Not only are differences in these areas important in the context of passing tax legislation in the next few weeks, but they also make it difficult for businesses to plan, Gimigliano said. "I don't know if there's ever been a harder time to be a head of tax at a large company trying to plan for the future."

This episode was recorded the morning of Dec. 5. The legislation is subject to change.