Accounting Periods. The taxable year or period for which the return is filed shall be the same as that for which the federal return is filed, and in every instance that a federal return is required, a corresponding State return shall be filed. Use of Federal Figures. The starting point for the Maryland return is the taxable income as defined in the Internal Revenue Code and developed on the federal return. Corporations included in a consolidated filing for federal purposes shall file separate Maryland returns and compute separate taxable income. Rate of Tax. The tax rate is 8.25 percent of Maryland taxable income.