Maryland Divorce ~ Absolute Divorce Waiting Periods
There is a provision for bringing the lawsuit against your spouse under each ground for an absolute divorce. If you claim that your spouse has committed adultery, you can bring the action for absolute divorce at any time. As long as you fulfill the Maryland residency requirement explained here http://www.divorce-and-child.com/blogs/maryland_divorce/archive/2008/12/01/maryland-divorce-residency.aspx there is no time limit when adultery is concerned.
In a claim of desertion you may have a time limit issue. Whether the desertion was actual or constructive, you must wait a year after the event of desertion to file an absolute divorce. To file a voluntary separation you must have been voluntarily separated for at least twelve months without cohabitation, which includes no nights under one roof and no sexual intercourse. The voluntary separation must be filed before an absolute divorce can be filed.
You can file for an absolute divorce if your spouse has been convicted of a felony or misdemeanor with a sentence of at least three years or an unspecified sentence in a penal institution and has served twelve months of that sentence. If your spouse has been confined to a mental institute, hospital or other similar medical facility for at least three years, you can then file for an absolute divorce as long as you have met residency requirements.
Source : How To Do Your Own Divorce In Maryland by Richard S. Granat (2004)