In Maryland, points are assessed to your license after you have been convicted of a moving violation. This conviction may occur in either Circuit Court or District Court. Details regarding the number of points that are assigned for each type of violation can be found by reading both Maryland's Annotated Code and Code of Maryland Regulations.
Points for traffic violations remain on your driver record until they are officially expunged by the Maryland Motor Vehicle Administration (MVA) after 3 years. Certain criteria must be met for the automatic expungement of points; if this criterion is not met you can request manual expungement, after 3 years from the date of the violation.
Points on your driving record are considered public information, and thus can be pulled up by an insurance company, employer or other public entity, for 3 years from the violation date. However, after 2 years from the violation date, the points are no longer considered "current" by the MVA and thus not counted as part of your accumulated points.
You may also find out information regarding points, and your driving record by checking with the Maryland Motor Vehicle Administration.