Contractors active in Maryland county permit records, grouped from public filings. Counts reflect permits attributed to each firm. Not every filing names a contractor, so counts here are a floor. A firm's actual permit activity is usually higher.
| Contractor | Trade | Counties | Permits | Last active |
|---|---|---|---|---|
| KAYWELL CONSTRUCTION CORPORATION | Plumbing | Frederick County | 5 | Jun 2026 |
| MID ATLANTIC COOPERATIVE SOLUTIONS DBA AERO ENERGY | Plumbing | Howard County | 5 | Jun 2026 |
| ONEIL PLUMBING | Plumbing | Howard County | 5 | Jun 2026 |
| AC&T | Plumbing | Frederick County | 4 | Jul 2026 |
| AMERICAN MASTERS PLUMBING CO LLC | Plumbing | Howard County | 4 | Jun 2026 |
| CATONS PLUMBING, DRAINS AND HEATING | Plumbing | Howard County | 4 | Jun 2026 |
| CATONSVILLE PROFESSIONAL SERVICES | Plumbing | Howard County | 4 | Jul 2026 |
| CONFERS PLUMBING LLC | Plumbing | Howard County | 4 | Jun 2026 |
| Contracting LLC Stephen Lewis Barrett | Plumbing | Frederick County | 4 | Jul 2026 |
| C & S MECHANICAL, LLC | Plumbing | Howard County | 4 | Jul 2026 |
| ENDZEL PLUMBING LLC | Plumbing | Howard County | 4 | May 2026 |
| FREDERICK PLUMBING & HEATING | Plumbing | Frederick County | 4 | May 2026 |
| Hatfield's Equipment | Plumbing | Frederick County | 4 | May 2026 |
| Ivan Reid | Plumbing | Frederick County | 4 | Jul 2026 |
| J & A CONSTRUCTION SERVICES, INC. | Plumbing | Howard County | 4 | Jun 2026 |
| JAMES E MORGAN | Plumbing | Frederick County | 4 | Jul 2026 |
| JR ROBERT L HALLEY | Plumbing | Frederick County | 4 | Jul 2026 |
| KINSLEY CONSTRUCTION LLC | Plumbing | Frederick County, Howard County | 4 | Jun 2026 |
| Kline's Plumbing, LLC | Plumbing | Frederick County | 4 | Jun 2026 |
| Mallick Mechanical Contractors | Plumbing | Frederick County, Howard County | 4 | Jun 2026 |
| MCALLISTER PLUMBING INC | Plumbing | Howard County | 4 | Jul 2026 |
| MCGUIRE PLUMBING & HEATING, INC. | Plumbing | Howard County | 4 | Jul 2026 |
| MOXLEY PLUMBING | Plumbing | Frederick County | 4 | Jun 2026 |
| OWINGS MECHANICAL | Plumbing | Howard County | 4 | Jul 2026 |
| PAUL VINCENT WOODS | Plumbing | Howard County | 4 | Jun 2026 |
| PLUMBING MASTERED, LLC | Plumbing | Howard County | 4 | Jul 2026 |
| PMC SERVICE LLC | Plumbing | Howard County | 4 | Jul 2026 |
| PUMPHREY PLUMBING LLC | Plumbing | Howard County | 4 | Jun 2026 |
| RAPID ROOTER PLUMBING COMPANY | Plumbing | Howard County | 4 | Jul 2026 |
| SUPERIOR MECHANICAL SERVICES | Plumbing | Frederick County, Howard County | 4 | Apr 2026 |
| THOMPSONGAS, LLC | Plumbing | Howard County | 4 | May 2026 |
| ABBOTT BROTHERS PLUMBING | Plumbing | Howard County | 3 | Jul 2026 |
| ABBOTT'S PLUMBING, INC | Plumbing | Howard County | 3 | Jul 2026 |
| ABDULS PLUMBING SERVICE, LLC | Plumbing | Howard County | 3 | May 2026 |
| Bayshore Construction Services, LLC | Plumbing | Frederick County | 3 | Jun 2026 |
| BRADLEY BUILDING SERVICES LLC | Plumbing | Howard County | 3 | Jun 2026 |
| BROWNS PLUMBING & HEATING, INC | Plumbing | Frederick County | 3 | Jul 2026 |
| B.T. Plumbing inc. | Plumbing | Frederick County | 3 | Jul 2026 |
| BW PLUMBING AND DRAIN LLC | Plumbing | Howard County | 3 | Jul 2026 |
| CHUCK SUSSAN PLUMBING AND HVAC | Plumbing | Howard County | 3 | May 2026 |
| COMPLETE COMFORT LLC | Plumbing | Howard County | 3 | Apr 2026 |
| Corey's Construction | Plumbing | Frederick County | 3 | May 2026 |
| DAY OR NIGHT HOME AND HEARTH | Plumbing | Howard County | 3 | Apr 2026 |
| Dead Rock Contractor Services | Plumbing | Frederick County | 3 | Jun 2026 |
| Easterday-Wilson Water Services, LLC | Plumbing | Frederick County | 3 | Jun 2026 |
| Elite 4 Roofing & Remodeling,LLC | Plumbing | Frederick County | 3 | Jul 2026 |
| GABE'S PLUMBING LLC | Plumbing | Howard County | 3 | Jul 2026 |
| GLOBAL HVAC LLC | Plumbing | Howard County | 3 | Jul 2026 |
| Holtzman Propane, LC | Plumbing | Frederick County | 3 | Jun 2026 |
| JBA'S PLUMBING | Plumbing | Howard County | 3 | May 2026 |
Source: county permit records. Updated monthly.