A border adjustment tax will probably make an appearance in the final tax reform plan, the Republicans' chief tax writer in the House of Representatives, Rep. Kevin Brady, told CNBC on Tuesday.

"My sense is that border adjustability has become a given. That it will be part of the final tax reform plan and now the discussions are how can it be designed in transition in a very positive way for importers," the chairman of the House Ways and Means Committee said on "Squawk Box."