As of January 1, 2018

1. No Alarm-battery powered or hard wired-may be older than 10 years from the date of manufacture.

2. Battery-only smoke alarms must be powered with a sealed, long life battery and have a silence/hush button.

3. 9-volt battery alarms are no longer permitted.

4. One alarm must be located on each level of the dwelling, including the basement.

5. One alarm must be located outside each "sleeping area".

6. Homes built or renovated after January 1, 2013 one alarm must be placed in each "sleeping room".

7. AC alarms more than 10 years old must be replaced. 

8. Hard-wired, AC devices must be replaced with hard-wired devices only.

www.mdrealtor.org