In this chapter, the following terms have the meanings indicated. Terms Defined. “Basic credit” means the research and development tax credit described in Regulation .02C(1) of this chapter. “Business entity” means a sole proprietorship, partnership, corporation, or other entity doing business in the State. “Credit year” means the year for which the credit is being claimed. “Department” means the Department of Business and Economic Development. “Growth credit” means the research and development tax credit described in Regulation .02C(2) of this chapter. “Maryland base amount” means the base amount as defined in §41(c) of the Internal Revenue Code, that is attributable to Maryland, determined by: Substituting “Maryland qualified research and development expense” for “qualified research expense”; Substituting “Maryland qualified research and development” for “qualified research”; and Using, instead of the “fixed base percentage”: The percentage that the Maryland qualified research and development expense for the 4 taxable years immediately preceding the taxable year in which the expense is incurred is of the gross receipts for those years; or For a taxpayer that has fewer than 4 but at least 1 prior taxable year, the percentage as determined under §B(6)(c)(i) of this regulation, determined using the number of immediately preceding taxable years that the taxpayer has. “Maryland adjusted base amount” means the Maryland base amount modified for a period of less than 12 months. “Maryland gross receipts” means gross receipts that are reasonably attributable to the conduct of a trade or business in the State, determined under COMAR 03.04.03.08. “Maryland qualified research and development” means qualified research, as defined in §41(d) of the Internal Revenue Code and regulations thereunder, that is conducted in the State. “Maryland qualified research and development expense” means qualified research expenses, as defined in §41(b) of the Internal Revenue Code and regulations thereunder, incurred for Maryland qualified research and development. “Small business” means a for-profit corporation, limited liability company, partnership, or sole proprietorship with net book value assets totaling, at the beginning or the end of the taxable year for which Maryland qualified research and development expenses are incurred, as reported on the balance sheet, less than $5,000,000. “Taxpayer” means an individual or a corporation required to pay an income tax or file an income tax return.