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Maryland's Updated Smoke Alarm Law

The new law will be placed into effect on January 1, 2018.


The law requires the replacement of battery-only operated smoke alarms with sealed units that have 10 year lithium-ion batteries and a silence/hush button feature.


The Smoke Alarm Law is a transition away from 9-volt battery-operated smoke alarms in an effort to achieve more reliable smoke alarm coverage in older dwellings.

Smoke alarms that are battery operated and presently exist by code or locations where there are no smoke alarms present must be replaced. Keep in mind it is never acceptable to remove required hard-wired smoke alarms and replace them with any type of battery-only operated devices.

Maryland's Smoke Alarm Law also requires the replacement of all smoke alarms 10 years after the manufacturer's date on the back of the alarm. This applies to both hard-wired and battery-operated smoke alarms. If the manufacturers date cannot be found, the alarm is most-likely outdated and needs to be replaced, see example below.

For existing homes:

Smoke alarm requirements for existing homes are based on when the home was constructed.  NFPA only requires smoke alarms outside each sleeping area and one on each level of the home. However, it also recommends that existing homes be equipped with at least the same number of smoke alarms required in new homes which includes smoke alarms present inside all sleeping rooms. The department’s position is consistent with the recommendation for new home construction.

For new construction:

New construction codes in Maryland have been updated and corresponds with the International Residential Code and NFPA 72, National Fire Alarm and Signaling Code. An AC powered, battery back-up smoke alarm is required in every bedroom, in the common area outside of the bedrooms and, on every other level of the dwelling unit. All required smoke alarms must be interconnected.

Smoke alarms which are monitored by an off-site monitoring company are not affected by this law. 

Off-Site Monitored Alarms

Do you have to replace a hard-wired alarm with a sealed battery?

No, hard-wired alarms can be replaced with a 9-volt battery, however, it is recommended that you replace it with a 10-year sealed battery backup.

Homes constructed prior to
July 1st, 1975

Battery operated smoke alarms must be replaced or upgraded with longlife, sealed battery smoke alarms, equipped with a hush feature.

Homes Constructed Between July 1st, 1975 and June 30th, 1990
Homes built after
January 1st, 1989

Smoke alarms should be replaced after 10 years of service and be AC powered with a battery back-up.

Homes are required at least one hard-wired, AC powered smoke alarm on every level of the home, including the basement. It is also required that the units be interconnected. If one required smoke alarm is activated, it will result in the sounding of all required alarms.

Maryland’s new Smoke Alarm Law is part of the Public Safety Article, Sections 9-101 through 9-109. For detailed information about Senate Bill 969:

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