An electrical panel upgrade in Southern Maryland costs $1,300 to $4,000 in 2026, with most homeowners in Calvert, St. Mary's, and Charles County paying $1,800 to $3,000 for a standard upgrade from a 100-amp panel to a 200-amp panel. A panel replacement, swapping an outdated, damaged, or recalled panel for a new one of the same amperage, costs $800 to $2,000. Adding a subpanel to serve a garage, workshop, or addition costs $400 to $1,750.
The electrical panel, the gray metal box in your basement, garage, or utility closet, is the point where the utility's power enters your house and is distributed to every circuit. It is the nerve center of your electrical system and the primary safety device protecting your home from overloads, short circuits, and electrical fires. When it is undersized for the demands placed on it, or when it is old enough that its breakers no longer trip reliably, it is the most dangerous single component in the house.
Many homes in Southern Maryland were built in the 1960s through 1990s with 100-amp or even 60-amp electrical services that were adequate for the appliances and electrical loads of the era. Today, with central air conditioning, electric water heaters, electric dryers, multiple refrigerators, home offices full of electronics, EV chargers, and the possibility of a whole-house generator or heat pump, 100 amps is often not enough. An overloaded panel trips breakers constantly, forces homeowners to choose which appliances to run at the same time, and, if the breakers are old or defective, may not trip at all, which is how electrical fires start.
Here is what an electrical panel upgrade costs in Southern Maryland, when you need one, what the process involves, and what to watch out for.
Electrical Panel Upgrade Cost by Service Size
| Upgrade | Panel + Installation Cost | New Service Line Included |
|---|---|---|
| Panel replacement (same amperage) | $800 to $2,000 | No, existing service line reused |
| 60-amp to 100-amp upgrade | $1,200 to $2,500 | Sometimes, depends on existing service line capacity |
| 100-amp to 200-amp upgrade | $1,300 to $3,000 | Yes, the service line from the meter to the panel is typically replaced |
| 200-amp to 400-amp upgrade | $2,000 to $6,000 | Yes, requires a new, heavier service line and possibly a meter upgrade |
| New 200-amp panel installation (new construction or addition) | $1,800 to $3,500 | Yes |
The 100-to-200-Amp Upgrade: $1,300 to $3,000
This is the most common electrical panel upgrade in Southern Maryland. The majority of homes built before 2000 in the tri-county area were wired with 100-amp service, and a 200-amp upgrade accommodates all current and near-future residential electrical demands, central air conditioning, electric cooking, electric hot water, a heat pump, an EV charger, and a whole-house generator transfer switch.
What is included in the price:
- A new 200-amp main breaker panel (30 to 42 circuit spaces)
- All new circuit breakers
- A new 200-amp main breaker
- Reconnection of all existing circuits to the new panel
- A new service entrance cable (the heavy cable from the meter to the panel) if the existing cable is undersized for 200 amps
- Coordination with the utility (SMECO in Southern Maryland) for the meter and service connection
- Electrical permit and inspection
- Labeling of all circuits
What can add to the cost:
| Additional Work | Cost |
|---|---|
| SMECO service upgrade (new meter base, new overhead or underground service line from the transformer) | $500 to $2,000+ (SMECO covers some of this, but the homeowner covers the meter base and the line from the meter to the panel) |
| Moving the panel to a new location (code compliance, accessibility, or remodel) | $800 to $3,000 |
| Replacing the meter base | $200 to $600 |
| Upgrading to arc-fault (AFCI) breakers on bedroom circuits (required by current code) | $35 to $60 per breaker |
| Upgrading to ground-fault (GFCI) breakers on kitchen, bath, garage, outdoor, and basement circuits | $35 to $60 per breaker |
| Grounding system upgrade (adding or replacing ground rods, bonding) | $200 to $800 |
| Drywall, siding, or finish repair after panel relocation | Variable |
Subpanel Installation: $400 to $1,750
A subpanel is a secondary panel fed from the main panel. It provides additional circuit capacity in a location away from the main panel, typically a detached garage, a workshop, a finished basement, an addition, or an outbuilding.
When a subpanel makes sense: you need more circuits in a specific area but your main panel has enough amperage to support them. For example, finishing a basement and adding 8 to 10 circuits for lighting, outlets, a bathroom, and a kitchenette, running all those circuits individually back to the main panel in the utility closet upstairs is expensive and creates a cable management problem. A subpanel in the basement, fed by one heavy feeder cable from the main panel, is cleaner, cheaper, and easier to manage.
Subpanel sizing: a 60-amp subpanel is typical for a finished basement or a detached garage with basic needs (lighting, outlets, a small shop). A 100-amp subpanel is appropriate for a workshop with heavy tools, an addition with its own HVAC, or any space with significant electrical load.
When You Need a Panel Upgrade
Signs Your Panel Is Undersized
Breakers trip frequently. If you cannot run the microwave and the toaster at the same time, or if the breaker trips every time the air conditioner cycles on while the dryer is running, the panel does not have enough capacity for the electrical load. Occasional breaker trips are normal, they mean the safety system is working. Frequent trips mean the circuits are overloaded.
You are using power strips and extension cords everywhere. A house that needs power strips on every outlet to run daily life does not have enough circuits, and the panel may not have enough spaces to add them. A panel upgrade adds circuit capacity.
Lights flicker or dim when large appliances start. When the air conditioner compressor kicks on and the lights dim momentarily, the electrical system is straining to deliver the startup current. In a properly sized system, you should not notice large appliances cycling on.
The panel is warm to the touch. A panel that is warm on the surface, or a main breaker that is warm or hot, is conducting more current than it should. This is a fire hazard and should be inspected by a licensed electrician immediately.
You are planning a major electrical addition. An EV charger (30 to 60 amps), a whole-house generator transfer switch, a heat pump, a hot tub (40 to 50 amps), or a kitchen remodel with new appliances may require more amperage than your current panel can supply. A 100-amp panel with a central air conditioner, an electric water heater, and an electric dryer is already running at 70 to 80 percent of capacity, adding a 50-amp EV charger pushes it over.
Panels That Need Replacement Regardless of Amperage
Some panels should be replaced even if the amperage is adequate, because the panels themselves have known safety defects.
Federal Pacific Electric (FPE) Stab-Lok panels. These were installed widely from the 1950s through the 1980s and are present in a significant number of Southern Maryland homes built during that era. The Stab-Lok breakers have a well-documented failure rate, studies found that up to 25 to 30 percent of FPE breakers fail to trip during an overload or short circuit. A breaker that does not trip does not cut the power during a fault, and the result is overheated wires, melted insulation, and electrical fire. The Consumer Product Safety Commission investigated FPE, and while no mandatory recall was ever issued, the consensus in the electrical industry is that FPE Stab-Lok panels should be replaced. If your home has one, replace it, this is not a theoretical risk.
Zinsco (Sylvania) panels. Manufactured from the 1970s through the 1990s, Zinsco panels have a design flaw where the bus bars (the metal strips that the breakers connect to) can overheat and melt the breaker housings, causing breakers to fuse to the bus and become unable to trip. Like FPE, Zinsco panels should be replaced.
Any panel with a fuse box. Fuse boxes predate circuit breakers. They work, a fuse blows when the circuit is overloaded, just like a breaker trips, but they are inconvenient (the fuse must be replaced, not reset), they tempt homeowners to install oversized fuses (a 30-amp fuse on a 15-amp circuit does not protect the wiring), and they do not meet current code. Insurance companies in Maryland increasingly either refuse to insure homes with fuse boxes or charge significantly higher premiums.
Any panel that shows scorch marks, melted plastic, a burning smell, or corrosion inside. Open the panel door (not the panel cover, only a licensed electrician should remove the cover) and look. Scorch marks on the panel face, discolored or melted breaker handles, a persistent burning or acrid smell, or visible rust and corrosion are signs of serious problems that require immediate professional inspection.
The Electrical Panel Upgrade Process
Step 1: Assessment and Quote
A licensed electrician inspects the existing panel, determines the current amperage, evaluates the condition of the panel and its components, reviews the electrical load of the home (existing circuits and planned additions), and recommends the appropriate upgrade. The electrician also determines whether the service entrance cable, the meter base, and the utility connection need upgrading, a 200-amp panel requires a 200-amp service entrance cable, and if the existing cable is only rated for 100 amps, it must be replaced.
Step 2: Permit
Electrical panel upgrades require a permit from the county, Calvert County Department of Planning and Zoning, St. Mary's County Department of Land Use and Growth Management, or Charles County Building Inspection. The electrician pulls the permit. Permit fees are typically $50 to $200.
Step 3: Utility Coordination
If the service entrance cable or the meter base is being replaced, the utility, Southern Maryland Electric Cooperative (SMECO) for most of the tri-county area, must disconnect the power at the meter, and then reconnect it after the work is done. The electrician coordinates the disconnect and reconnect with SMECO. In some cases, SMECO must upgrade its side of the connection (the overhead or underground service line from the transformer to the meter) if the existing line cannot carry 200 amps. SMECO covers its own infrastructure upgrades, but the homeowner covers the meter base and everything from the meter to the panel.
Step 4: Installation (4 to 8 Hours)
The power will be off for most of the day. A panel upgrade requires the power to be disconnected at the meter. Expect 4 to 8 hours without power for a standard upgrade. Plan accordingly, charge devices, move refrigerator and freezer contents to a cooler if the outage will exceed 4 hours, and do not schedule the work during extreme heat or cold when HVAC is critical.
What happens during installation:
- SMECO disconnects the power at the meter (or the electrician pulls the meter if permitted).
- The electrician removes the panel cover and disconnects all circuits from the old panel.
- The old panel is removed.
- If the service entrance cable is being upgraded, the new cable is run from the meter base to the panel location.
- The new panel is mounted and connected to the service entrance cable.
- All existing circuits are reconnected to new breakers in the new panel. The electrician maps and labels each circuit.
- New breakers are installed: standard breakers for most circuits, AFCI breakers for bedroom circuits, and GFCI breakers for wet and outdoor locations as required by current code.
- The grounding and bonding system is connected and verified.
- SMECO reconnects the power.
- The electrician tests every circuit, verifies all breakers function, and confirms the panel is energized and operating correctly.
Step 5: Inspection
The county electrical inspector visits after the work is complete to verify the installation meets code. The inspection is required before the permit can be closed. If the inspector finds deficiencies, the electrician corrects them and the inspector returns. Pass the inspection, and the work is done.
What Current Code Requires (and What It Means for Your Wallet)
When you upgrade a panel, the new installation must meet the current National Electrical Code (NEC) as adopted by Maryland, not the code that was in effect when the house was built. This means the upgrade may trigger requirements that did not exist when the original panel was installed.
Arc-fault circuit interrupter (AFCI) breakers. Current code requires AFCI protection on most living-area circuits, bedrooms, living rooms, dining rooms, hallways, and closets. AFCI breakers detect arc faults (sparks caused by damaged or deteriorated wiring) that standard breakers cannot detect, and they trip to prevent fires. They cost $35 to $60 per breaker versus $5 to $10 for a standard breaker. A panel upgrade that moves 10 circuits to AFCI breakers adds $250 to $500 to the project.
Ground-fault circuit interrupter (GFCI) breakers or outlets. Current code requires GFCI protection in kitchens, bathrooms, garages, outdoors, basements, laundry areas, and within 6 feet of any sink. GFCI devices detect ground faults (current leaking to ground through a person or water) and cut the power in milliseconds to prevent electrocution. GFCI breakers cost $35 to $60 each.
Whole-house surge protection. As of the 2020 NEC (adopted in Maryland), all new panel installations must include a whole-house surge protection device (SPD). An SPD mounts in or beside the panel and absorbs voltage spikes from lightning, power line surges, and grid switching before they reach your circuits and electronics. Cost: $150 to $500 installed. This is a worthwhile investment in Southern Maryland, where summer thunderstorms produce frequent lightning and power surges.
Electrical Panel Upgrades and Home Improvements
EV Charger Installation
A Level 2 EV charger, the standard home charger that delivers a full charge overnight, requires a dedicated 40- to 60-amp, 240-volt circuit. On a 100-amp panel that already serves the HVAC, water heater, dryer, and range, there is often not enough remaining capacity for a 50-amp EV circuit. A 200-amp upgrade provides the headroom. Many homeowners combine the panel upgrade and EV charger installation into one project, which saves on the second electrician visit.
Whole-House Generator
A whole-house standby generator connects to the electrical panel through a transfer switch, an automatic device that senses a power outage, starts the generator, and switches the panel from utility power to generator power. The transfer switch must be compatible with the panel amperage and requires space in or beside the panel. A panel upgrade is often done simultaneously with generator installation.
Heat Pump Conversion
If you are converting from a gas furnace to an electric heat pump (or a dual-fuel system), the heat pump's electrical demand, particularly the backup electric resistance heat strips, can add 30 to 60 amps of load. A 100-amp panel may not support this without displacing other circuits. Upgrading to 200 amps ensures the heat pump, the existing HVAC, and all other household loads can run simultaneously without tripping breakers.
Kitchen and Bathroom Remodels
Modern kitchen remodels add significant electrical load: a 50-amp range circuit, a 20-amp dishwasher circuit, multiple 20-amp small appliance circuits for the countertop, under-cabinet lighting, and potentially an electric cooktop or wall oven on its own 40- to 50-amp circuit. A panel that is already full (no empty breaker spaces) cannot accommodate these new circuits without an upgrade or a subpanel.
SMECO and the Utility Side
Southern Maryland Electric Cooperative (SMECO) provides electricity to most of Calvert, St. Mary's, and Charles County. When your panel upgrade requires a new meter base or a larger service entrance, SMECO is involved.
What SMECO provides at no charge to you: the utility infrastructure from the transformer to the meter point (the overhead or underground service line on their side). If your upgrade requires a larger service line from the transformer, SMECO handles and funds that.
What you pay for: the meter base (the housing that holds the meter), the service entrance cable from the meter to the panel, and all wiring from the panel inward. The meter base costs $200 to $600 for the unit, and the electrician installs it as part of the project.
Scheduling. SMECO typically requires 5 to 10 business days' notice for a planned disconnect and reconnect. Your electrician handles the scheduling. In some cases, particularly if the service line from the transformer needs upgrading, the lead time can be longer. Do not schedule the panel upgrade for a day when you cannot afford to be without power for 4 to 8 hours.
Frequently Asked Questions
How much does it cost to upgrade from 100 amps to 200 amps in Southern Maryland? Most homeowners pay $1,300 to $3,000 for a 100-to-200-amp panel upgrade, including the new panel, breakers, service entrance cable, permit, and installation. If the meter base, grounding system, or utility service line also need upgrading, the total can reach $3,500 to $4,500.
How do I know if I have a 100-amp or 200-amp panel? Open the panel door (not the inner cover). The main breaker at the top of the panel is labeled with its amperage, typically "100" or "200." If you have a fuse box instead of breakers, the main fuse or disconnect is labeled. You can also check the service entrance cable and meter base, which are labeled with their amperage rating. If you are unsure, an electrician can confirm in minutes.
Is a 200-amp panel enough for a modern home? Yes, for the vast majority of residential homes. A 200-amp panel supports central air conditioning, an electric water heater, an electric range, an electric dryer, a heat pump, an EV charger, a whole-house generator, and all standard household circuits simultaneously. A 400-amp service is only needed for very large homes (over 4,000 square feet), homes with multiple HVAC systems, or homes with unusually high electrical loads (large workshops, multiple EV chargers, commercial-grade equipment).
Do I need a permit for a panel upgrade? Yes. Electrical panel upgrades require a permit from the county building inspection department, Calvert, St. Mary's, or Charles County. The permit ensures the work is inspected for code compliance. Your electrician should pull the permit as part of the project. Any electrician who suggests skipping the permit is a red flag.
How long does a panel upgrade take? A standard panel upgrade takes 4 to 8 hours in one day. The power is off for most of that time. If the project involves relocating the panel, upgrading the meter base, or running a new service entrance cable, it may take a full day or extend into a second day.
Will upgrading my panel reduce my electricity bill? No. A larger panel does not use more or less electricity, it simply provides the capacity to safely deliver more power when needed. Your electricity bill is determined by the appliances and devices you use, not by the panel size. However, if your current panel is causing you to use inefficient workarounds (space heaters because the heat pump circuit trips, for example), fixing the underlying electrical issue may indirectly reduce your energy use.
Does a panel upgrade increase home value? Yes, indirectly. A 200-amp panel is the expected standard for a modern home, and a home with a 100-amp or less panel is flagged by home inspectors as a limitation. Buyers, and their agents, know that a panel upgrade costs $2,000 to $3,000, and they factor that into their offer. More importantly, a panel upgrade removes a barrier to other improvements (EV charger, generator, heat pump, kitchen remodel) that directly increase value.
Is it safe to do any electrical panel work myself? No. Electrical panel work involves the service entrance, the connection between the utility and your home's wiring, which carries enough current to kill or start a fire. It requires a licensed electrician, a permit, and an inspection. Even replacing a single breaker in the panel carries risk if you are not trained. In Maryland, electrical work beyond basic homeowner tasks (changing a light switch, replacing an outlet) must be done by a licensed electrician.
I have a Federal Pacific or Zinsco panel. How urgent is the replacement? These panels have well-documented safety defects. Federal Pacific Stab-Lok breakers fail to trip at rates of 25 to 30 percent in testing, and Zinsco breakers can fuse to the bus bar and become inoperable. Neither panel is considered safe by the modern electrical industry. Replacement should be a high priority, not something to defer for years. If you are buying a home with an FPE or Zinsco panel, factor the replacement cost ($1,500 to $3,000) into your purchase decision and negotiate accordingly.
Panel outdated, breakers tripping, or planning a big upgrade? Gray & Sons Contracting has been improving Southern Maryland homes for 50 years. We will assess your electrical panel, recommend the right upgrade, and coordinate with SMECO to get it done safely. Get a Free Estimate