Md. Code Ann., Ins. § 6-304
All taxes imposed by this subtitle that are not paid within 30 days after the Commissioner issues the notice of the amount due are subject to a penalty of 5% and interest at the rate determined under § 13-604 of the Tax-General Article for each month after the date of the notice that the tax was due.
Added by Acts 1997, c. 57, § 1, eff. Oct. 1, 1997.