This might help you: https://www.law.cornell.edu/cfr/text/26/1.179-3

1.179-3(f)Dispositions and other transfers of section 179 property -

(1)In general. Upon a sale or other disposition of section 179 property, or a transfer of section 179 property in a transaction in which gain or loss is not recognized in whole or in part (including transfers at death), immediately before the transfer the adjusted basis of the section 179 property is increased by the amount of any outstanding carryover of disallowed deduction with respect to the property. This carryover of disallowed deduction is not available as a deduction to the transferor or the transferee of the section 179 property.