Md. Code Ann., Cts. & Jud. Proc. § 6-408

For a period of 30 days after the entry of a judgment, or thereafter pursuant to motion filed within that period, the court has revisory power and control over the judgment. After the expiration of that period the court has revisory power and control over the judgment only in case of fraud, mistake, irregularity, or failure of an employee of the court or of the clerk’s office to perform a duty required by statute or rule.