(a) If a taxable entity acquires a controlling interest in another taxable entity or in a separate unit of another taxable entity during a tax period with respect to which the acquiring taxable entity claims a credit under this subchapter, the amount of the acquiring taxable entity’s qualified research expenses equals the sum of:
(1) the amount of qualified research expenses incurred by the acquiring taxable entity during the period on which the report is based; and
(2) subject to Subsection (d), the amount of qualified research expenses incurred by the acquired taxable entity or unit during the portion of the period on which the report is based that precedes the date of the acquisition.
(b) A taxable entity that sells or otherwise transfers to another taxable entity a controlling interest in another taxable entity or in a separate unit of a taxable entity during a period on which a report is based may not claim a credit under this subchapter for qualified research expenses incurred by the transferred taxable entity or unit during the period if the taxable entity is ineligible for the credit under § 171.653 or if the acquiring taxable entity claims a credit under this subchapter for the corresponding period.

(c) If during any of the three tax periods following the tax period in which a sale or other transfer described by Subsection (b) occurs, the taxable entity that sold or otherwise transferred the controlling interest reimburses the acquiring taxable entity for research activities conducted on behalf of the taxable entity that made the sale or other transfer, the amount of the reimbursement is:
(1) subject to Subsection (e), included as qualified research expenses incurred by the taxable entity that made the sale or other transfer for the tax period during which the reimbursement was paid; and
(2) excluded from the qualified research expenses incurred by the acquiring taxable entity for the tax period during which the reimbursement was paid.
(d) An acquiring taxable entity may not include on a report the amount of qualified research expenses otherwise authorized by Subsection (a)(2) to be included if the taxable entity that made the sale or other transfer described by Subsection (b) received an exemption under § 151.3182 during the portion of the period on which the acquiring taxable entity’s report is based that precedes the date of the acquisition.
(e) A taxable entity that makes a sale or other transfer described by Subsection (b) may not include on a report the amount of reimbursement otherwise authorized by Subsection (c)(1) to be included if the reimbursement is for research activities that occurred during a tax period under this chapter during which that taxable entity received an exemption under § 151.3182.