Maryland Courts and Judicial Proceedings Section 3-2C-02
(a)   (1)   Except as provided in subsections (b) and (c) of this section, a claim shall be dismissed, without prejudice, if the claimant fails to file a certificate of a qualified expert with the court.
(2)   A certificate of a qualified expert shall:
(i)   Contain a statement from a qualified expert attesting that the licensed professional failed to meet an applicable standard of professional care;
(ii)   Subject to the provisions of subsections (b) and (c) of this section, be filed within 90 days after the claim is filed; and
(iii)   Be served on all other parties to the claim or the parties' attorneys of record in accordance with the Maryland Rules.
(b)   (1)   Upon written request made by the claimant within 30 days of the date the claim is served, the defendant shall produce documentary evidence that would be otherwise discoverable, if the documentary evidence is reasonably necessary in order to obtain a certificate of a qualified expert.
(2)   The time for filing a certificate of a qualified expert shall begin on the date on which the defendant's production of the documentary evidence under paragraph (1) of this subsection is completed.
(3)   The defendant's failure to produce the requested documentary evidence under paragraph (1) of this subsection shall constitute a waiver of the requirement that the claimant file a certificate of a qualified expert as to that defendant.
(c)   (1)   Upon written request by the claimant and a finding of good cause by the court, the court may waive or modify the requirement for the filing of the certificate of a qualified expert.
(2)   The time for filing the certificate of merit of a qualified expert shall be suspended until the court rules on the request and, absent an order to the contrary, the certificate shall be filed within 90 days of the court's ruling.
(d)   Discovery by the defendant as to the basis of the certificate of a qualified expert shall be available.