Md. Code, Estates and Trusts § 3–407

(a) (1) The election by a surviving spouse to take an elective share shall be made within the later of:

(i) 9 months after the date of the decedent’s death; or

(ii) 6 months after the first appointment of a personal representative.

(2) (i) Within the period for making an election, the surviving spouse may file with the court a petition for an extension of time, with a copy given to the personal representative.

(ii) For good cause shown, the court may extend the time for election for a period not to exceed 3 months at a time.

(b) The surviving spouse may withdraw the election at any time before the expiration of the time for making the election to take an elective share.