CO Detector Requirements in Maryland: Homes, Rentals, and Hotels

Last verified: February 16, 2026

Maryland carbon monoxide detector laws are governed by Public Safety sections 12-1101 through 12-1106 and apply across multiple occupancy categories, including covered homes, rental units, and lodging settings. The statutory framework combines applicability language, installation rules, and approved-device requirements, with local enforcement playing a major operational role.

Maryland requirements include location logic for sleeping areas and level-based placement in rental units, while hotel and rooming scenarios carry additional trigger language tied to adjacent risk conditions. Because statewide penalty language is less centralized, owners and operators should treat inspection readiness, documentation, and correction workflow as primary compliance controls.

The most defensible Maryland approach is section-by-section mapping of applicability, placement, and maintenance obligations before occupancy, turnover, or permit closeout. Maryland operators should maintain subsection-level records for each unit and occupancy type.

In 60 Seconds

CO detector requirements for Maryland
Applies to homes?	Yes
Applies to rentals?	Yes
Applies to hotels/STRs?	Yes

When Are CO Alarms Required?

Buildings with fuel-burning appliances
New construction
When building permits are required
Public Safety 12-1102 includes newly constructed fossil-fuel dwellings with specified permit context and also includes hotel, lodging, rooming, and rental dwelling categories.

Where to Install CO Alarms

Central location outside each sleeping area within a dwelling under Public Safety 12-1104(a).
For rental dwelling units, outside and in the immediate vicinity of each separate sleeping area and on every level including basement under 12-1104(c).
For hotel, lodging, and rooming contexts, placement rules include listed guest-room and adjacency scenarios under 12-1104(b).
Alternative centralized system options are addressed in 12-1104(d).

For detailed placement guidance beyond legal requirements, see where to place carbon monoxide detectors.

Device Requirements

Approved alarms listed by nationally recognized testing laboratories accepted by Maryland State Fire Marshal framework.
Power options include AC with battery backup, sealed long-life battery options, or approved control-unit pathways as specified in 12-1101.
Combination smoke and CO devices are permitted when statutory listing standards are met.

Landlord and Tenant Responsibilities

Landlord: Rental owners must provide required alarm placement and operability under statutory placement sections.

Tenant: Occupants may not render required carbon monoxide alarms inoperable under Public Safety 12-1105.

Local jurisdiction procedures may add operational detail on inspections and corrective timelines.

Enforcement

Enforced by: Local fire and building authorities implement enforcement in practice, with statewide statutory framework in Public Safety 12-1101 through 12-1106.

Enforcement typically occurs:

During local inspections, permit workflow, and occupancy compliance checks.
During follow-up actions where alarms are missing, inoperable, or improperly placed.

Penalties for Non-Compliance

Public Safety 12-1105 prohibits rendering alarms inoperable, but the cited statewide sections do not present one simple statewide CO-specific fine schedule.

Public Safety 12-1105 and 12-1106 context.

Additional Notes

Maryland statewide text should be read with local enforcement practice and occupancy-specific interpretation.
The cited statewide sources do not equate all short-term rental models to a single statutory category without local classification review.

Official Sources & References

Maryland Public Safety 12-1101 (definitions and approved alarm framework) — 12-1101 (state code, accessed 2026-02-16)
Device, listing, and power-path framework for Maryland CO alarm requirements.
Maryland Public Safety 12-1102 (applicability) — 12-1102 (state code, accessed 2026-02-16)
Core scope and trigger language for covered dwelling and lodging categories.
Maryland Public Safety 12-1103 (combination devices) — 12-1103 (state code, accessed 2026-02-16)
Combination smoke and carbon monoxide device standards.
Maryland Public Safety 12-1104 (installation locations) — 12-1104 (state code, accessed 2026-02-16)
Detailed placement requirements for dwellings, rentals, and lodging contexts.
Maryland Public Safety 12-1106 (local authority) — 12-1106 (state code, accessed 2026-02-16)
Confirms local jurisdictions may enact more stringent laws.

Disclaimer: This information is provided for general guidance and is not legal advice. Requirements may vary by city, county, and building type. Always verify current rules with local authorities and official sources.

Frequently Asked Questions

Which Maryland law sections govern carbon monoxide detector requirements?

Maryland compliance is anchored in Public Safety sections 12-1101 through 12-1106, with 12-1102 and 12-1104 carrying core applicability and placement language. These sections should be read together because one part defines scope while another part sets installation logic for dwellings, rentals, and lodging contexts. Operators who review only one section often miss key trigger details. Maryland teams should keep section-level citations in every compliance checklist and permit file. In Maryland, include Public Safety section citations and local fire-marshal notes in every inspection file.

What Maryland properties are most likely to trigger CO alarm obligations?

Public Safety 12-1102 includes newly constructed fossil-fuel dwellings in specified permit contexts and also includes rental units plus hotel, lodging, and rooming categories. This means both residential owners and hospitality operators can fall within statewide CO rules, depending on occupancy and building conditions. The safest approach is occupancy mapping before project start or turnover. Maryland operators should document why each property is inside or outside the cited statutory scope. In Maryland, include Public Safety section citations and local fire-marshal notes in every inspection file.

Where must alarms be placed under Maryland rules?

Maryland placement rules in Public Safety 12-1104 include central sleeping-area proximity for dwellings, level-based coverage in rental units, and specific trigger-based location rules in lodging scenarios. There is also centralized-system language for certain configurations under 12-1104(d). Because placement is section-specific, operators should create room-by-room plans and keep as-built records for inspectors. Maryland files should reference the exact subsection used for each placement decision. In Maryland, include Public Safety section citations and local fire-marshal notes in every inspection file.

What happens if alarms are missing or inoperable in Maryland?

Public Safety 12-1105 prohibits rendering required carbon monoxide alarms inoperable, and local authorities can enforce compliance through inspections and correction workflow. The cited statewide sections do not present one simple CO-only fine table in this statewide framework, but enforcement and liability risk still increase when deficiencies remain unresolved. Owners should address notices quickly and preserve remediation evidence. Maryland compliance quality is often judged by documentation speed and completeness. In Maryland, include Public Safety section citations and local fire-marshal notes in every inspection file.

How should landlords and lodging operators document Maryland compliance?

Landlords and lodging operators should maintain section-linked records for installation, testing, corrective work, and occupancy turnover in each property file. Because Maryland rules differ by occupancy category, a single generic checklist is usually insufficient. Property managers should align lease documents, service tickets, and inspection responses with the correct Public Safety section references. This process reduces disputes and supports defensible compliance during audits. In Maryland, include Public Safety section citations and local fire-marshal notes in every inspection file.

Which Maryland-to-Virginia gap most changes CO alarm enforcement planning?

Maryland uses a section-driven Public Safety framework with local enforcement variation, while Virginia operators may rely on a different statute-and-code combination depending on occupancy type and jurisdiction. Teams operating in both states should avoid a shared template and map each state triggers and placement rules independently. For nearby-state benchmarking before finalizing Mid-Atlantic SOPs, review Virginia CO detector laws and align records by state-specific section references. In Maryland, include Public Safety section citations and local fire-marshal notes in every inspection file.

Practical CO Detector Guides

Beyond legal requirements, these guides help you choose, install, and maintain CO alarms:

Where to place carbon monoxide detectors — room-by-room placement recommendations
CO detector beeping patterns — what different alarms mean
What to do if your detector goes off — emergency response checklist
CO resources and links — official agencies and safety information