Acquisitions or dispositions of trades or businesses should be identified when calculating the R&D tax credit for both the base period and the current year qualified expenditures. Consistency between these periods is required per IRC §41(c)(5). For example, if a company acquires another entity in the current year, that entity’s R&D expenses are included in the current year R&D tax credit calculation and the entity’s prior R&D expenses will also need to be reflected in the base period years.