Maryland Code, Insurance § 4-209

(1) premiums on lawfully procured surplus lines insurance;

(2) premiums on independently procured insurance on which a tax has been paid under § 4-211 of this subtitle; or

(3) wet marine and transportation insurance.

(b)(1) If an unauthorized insurer effects, continues, or renews insurance on a subject resident, located, or to be performed in the State, the unauthorized insurer shall pay to the Commissioner, before March 1 of the next calendar year, a premium receipts tax of 3% of gross premiums charged for the insurance.

(2) For policies effective before July 21, 2011:

(3) For policies effective on or after July 21, 2011, if the State is the insured's home state, the premium receipts tax shall be computed on the entire premium at the rate specified in paragraph (1) of this subsection.

(4) Insurance that an unauthorized insurer effects, continues, or renews on a subject resident, located, or to be performed in the State that is procured through negotiations or an application wholly or partly occurring or made in or from within or outside of the State, or for which premiums wholly or partly are remitted directly or indirectly from in or outside of the State, is deemed to be insurance procured, continued, or renewed in the State.

(1) 25% of the tax due; and

(2) an amount computed at the rate of 1% per month or any part of a month after the date the payment was due to the date the payment is made.