Example. A incurs $1,000 in clinical testing expenses for which a $500 credit is allowable under section 28. A also elects under section 174 of the Code to amortize these expenses over a 5-year period beginning in the year the credit is claimed. Under paragraph (a), the current year amortization deduction of $200 ($1,000 ÷ 5) is disallowed. Moreover, the amount which would otherwise be capitalized, $800, is reduced by the excess of the amount of the section 28 credit claimed for the taxable year over the amount of the allowable section 174 amortization deduction for the taxable year, or $300 ($500-$200). Thus, the amount chargeable to the capital account for the taxable year is $500 ($800-$300). A is entitled to amortize $500 over the remaining amortization period resulting in a deduction of $125 for each of the remaining four years.
26 C.F.R. §1.280C-3