Hi, Company A bought assets in 2015 and transferred assets to Company B in exchange of stocks. Company A did not take section 179 deduction on these assets, can company B take section 179?

Can you please direct me to the tax law relating to this? Thank you.

You must use the assets over half the time for business in the year in which you buy it. I mean it needs to be placed in service (i.e., purchased, acquired, or converted to business use) during the current tax year. Then, Co B will apply Section 179 deduction on those biz use assets.