Who licenses what in Maryland
| Work | License | Where to check |
|---|---|---|
| Remodeling, repairs, roofing, siding, windows, solar installation on an existing home | MHIC home improvement contractor (and salesperson) license | Home Improvement Public Query |
| New homes, including modular | Home Builder Registration Unit, Office of the Attorney General | Attorney General |
| Electrical | State Board of Master Electricians license; MHIC says a "licensed master electrician is required to hook the panels to the electric system" on solar jobs | Electricians search |
| Plumbing and gasfitting | State plumbing license; Baltimore County also licenses its own plumbing and gasfitting contractors | Plumbing search; Baltimore County |
| Heating and air conditioning | State HVACR license; some counties also require local licenses or permits (HVACR Board county list) | HVAC search |
MHIC's FAQ answers dozens of edge cases ("Do You Need a License to Do That?"), from central vacuums (yes) to solar panels (yes, wherever they are mounted).
How to look a contractor up, step by step
- Get the MHIC license number from the contract. Only an MHIC-licensed contractor may sign a home improvement contract with you; subcontractors under them no longer need their own license.
- Search the Home Improvement Public Query by contractor personal name or business name. It covers "active licensees practicing in the State of Maryland". For disciplinary actions, the page says to contact the Commission: 410-230-6231 or 1-888-218-5925.
- Ask for the master electrician's, plumber's or HVACR license number and search the matching state search on the license search page.
- Check the county. In Howard County the electrical permit is signed by a master electrician licensed by the Howard County Board of Electrical Examiners; in Baltimore County only a county-licensed plumbing or gasfitting contractor can apply for a plumbing permit; in Montgomery County the applicant needs a Master license from the Maryland State Board of Electricians.
- Ask for proof of at least $500,000 of general liability insurance, the MHIC minimum since 1 June 2024.
- Look up the address's permits (guides below).
The MHIC Guaranty Fund
Licensed contractors pay into the Fund: $100 with an original license and $175 every two years on renewal. It "compensates homeowners for actual monetary losses due to poor workmanship or failure to perform a home improvement contract", and "applies only to work done by licensed contractors" (MHIC). When many claims hit one contractor, MHIC can pay approved claims proportionately, as it has announced for suspended firms. MHIC runs free workshops on filing claims. We did not find the per-claim maximum on MHIC's pages, so ask the Commission.
Our permit data in Maryland
| Place | Permits | Period | Electrical | Plumbing | HVAC |
|---|---|---|---|---|---|
| Prince George's County | 78,924 | May 2021 – Apr 2023 | 32,079 | — | 12,659 |
| Baltimore County | 72,744 | Oct 2024 – Sep 2026 | 25,685 | 22,473 | 5,336 |
| Montgomery County | 57,855 | Oct 2024 – Sep 2026 | 22,023 | — | 15,557 |
| Baltimore | 37,029 | Jun 2025 – Sep 2026 | 6,348 | 6,597 | 5,612 |
| Howard County | 33,773 | Dec 2023 – Nov 2025 | 11,976 | 9,666 | 3,024 |
| Rockville | 5,779 | Oct 2024 – Sep 2026 | 942 | 1,636 | 880 |
A dash means the file does not carry that kind of permit in useful numbers: plumbing permits in Montgomery and Prince George's counties are issued by WSSC Water, not the county. Prince George's County's file ends in April 2023. These are permit counts, not contractor lists. Local permit rules: Baltimore County electrical and plumbing, Howard County electrical, Montgomery County electrical, Prince George's County electrical and Baltimore remodel permits.
Red flags on a Maryland job
- No MHIC number on the contract, or a number that is not in the public query.
- A home builder with only an MHIC license for a new house.
- A solar or remodel contract where nobody names the master electrician.
- A plumber in Baltimore County with a state license but no county license.
- Liability insurance under $500,000.
How we know this
MHIC rules, the Guaranty Fund assessment and insurance minimum are quoted from the Maryland Home Improvement Commission's home and FAQ pages and the Home Improvement Public Query, read 25 October 2026. County licensing rules are from the county pages cited in our Maryland permit guides, read 24 October 2026. Counts come from each county's or city's public permit file, read 19 October 2026; we have not matched Maryland contractor names to license records.
Numbers come from public permit records in 57 cities, data through October 19, 2026. Nobody paid to be on this page and nobody can.
Questions
- Who needs an MHIC license in Maryland?
Anyone who contracts with a homeowner for home improvement, which the Maryland Home Improvement Commission defines as "alteration, remodeling, repair or replacement of a building or part of a building used as a residence". Since 2016 subcontractors working for an MHIC-licensed contractor do not need their own license.
- Does an MHIC license cover building a new house?
No. MHIC says its license "does not cover new home construction"; builders must register with the Home Builder Registration Unit of the Office of the Attorney General.
- What insurance must a Maryland home improvement contractor carry?
Since 1 June 2024, general liability insurance of at least $500,000 (Business Regulation Article § 8-302.1).
- What is the MHIC Guaranty Fund?
A fund paid for by licensed contractors (a $100 assessment on an original license, $175 on each two-year renewal) that "compensates homeowners for actual monetary losses due to poor workmanship or failure to perform a home improvement contract". It applies only to work by licensed contractors.
- Where do I check a Maryland electrician or plumber?
On the Maryland Department of Labor's license searches (labor.maryland.gov/pq), which have separate searches for Electricians, Plumbing and HVAC. Some counties also license trades. Baltimore County licenses its own plumbing and gasfitting contractors, and Howard County its master electricians.
Build your own list
Pick your city and the kind of work. Every firm with a permit on record, sorted by what you value.
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- Maryland Home Improvement Commission — Maryland Department of Labor (2026-10-25)
- Home Improvement Public Query (license search) — Maryland Department of Labor (2026-10-25)
- FAQs — Do You Need a License to Do That? — MHIC (2026-10-25)
- Occupational and Professional Licensing license searches — Maryland Department of Labor (2026-10-25)
- County License/Permits — Maryland HVACR Board (2026-10-24)
- What You Need to Know About Electrician Licenses and Permits — Montgomery County DPS (2026-10-24)
- Plumbing and Gasfitting Licensing — Baltimore County Permits, Approvals and Inspections (2026-10-24)
- Building Permits — Baltimore City DHCD (2026-10-24)