A home defibrillator is not a substitute for emergency services, and most people do not need one

An automated external defibrillator (AED) is a device that delivers an electric shock to restart a heart that has stopped beating effectively. If you are thinking about buying one for your home or workplace, the first thing to understand is that an AED only works during the first few minutes after cardiac arrest—the window closes quickly. Most people who survive cardiac arrest outside a hospital get there because someone called 911 immediately and started CPR right away. The defibrillator matters, but it matters second.

Home AEDs are uncommon because cardiac arrest in young, healthy people is rare. If someone in your household has a known heart condition that puts them at high risk, or if your workplace is far from an ambulance station, a home or workplace AED may make sense. Otherwise, the money spent on a device you hope never to use might be better spent on CPR training for the people around you—which costs far less and actually saves lives in the moment.

Key Takeaways

  • An AED only works during the first few minutes after cardiac arrest, and calling 911 and starting CPR are more important than the device itself.
  • Home AEDs are most useful if someone in your household has a diagnosed heart condition that puts them at high risk of sudden cardiac arrest.
  • AEDs cost between $1,200 and $2,500 for a new device, plus ongoing costs for replacement pads and batteries every few years.
  • If you buy an AED, you must train the people who live or work near it on how to use it, because an untrained person may hesitate in a crisis.
  • Some workplaces and public spaces are required by law to have an AED on site, but most homes are not.

Who actually needs a home or workplace AED

Sudden cardiac arrest in adults under 50 without known heart disease is uncommon—roughly 1 in 100,000 people per year in that age group. If you have a family member with a history of sudden cardiac death, a genetic heart condition, or a diagnosis like hypertrophic cardiomyopathy or long QT syndrome, the risk is much higher, and a home AED becomes a reasonable choice. The same applies if you live or work in a rural area where an ambulance may take 15 or 20 minutes to arrive.

Workplaces in certain industries—gyms, sports facilities, airports, and some office buildings—are required by state or local law to have an AED on site. If your workplace is not required to have one but employs people with known heart conditions, or if employees regularly engage in strenuous activity, your employer may choose to install one. A workplace AED is most useful if staff are trained and the device is mounted in a visible, accessible location.

If you do not fall into either category, the evidence does not support buying a home AED. The money is better spent on CPR training for family members or coworkers, which costs $50 to $150 per person and has been shown to improve survival rates.

What an AED costs and what you pay for over time

A new AED for home or workplace use costs between $1,200 and $2,500, depending on the brand and features. Semi-automatic models (which require you to press a button to deliver the shock) are less expensive than fully automatic ones (which deliver the shock without user input). For a workplace, semi-automatic is standard; for a home, fully automatic may feel less intimidating in a crisis, though both work.

The upfront cost is not the only expense. AED pads—the adhesive patches that stick to the person's chest and deliver the shock—expire and must be replaced every 2 to 5 years, depending on the brand. Replacement pads cost $50 to $150 per set. The device's battery also expires, usually every 3 to 5 years, and replacement batteries cost $100 to $300. If you buy a device and never use it, you will still spend $150 to $450 every few years just to keep it ready. Some devices have a monthly or annual monitoring fee ($10 to $30 per month) that alerts you if the pads or battery are failing.

Before you buy, calculate the total cost of ownership over 10 years—device, pads, batteries, and any monitoring fees—to decide whether it fits your budget and your actual risk.

How to choose between AED models and brands

The major brands sold for home and workplace use are Philips HeartStart, Zoll AED Plus, Cardiac Science Powerheart, and Defibtech. All are cleared by the FDA and work similarly: they analyze the heart rhythm, tell you whether a shock is needed, and deliver it if one is. The differences are mainly in size, weight, battery life, and user interface.

For a home, you want a device that is easy to find and easy to use under stress. Fully automatic models require no decision-making—you attach the pads and the device delivers the shock on its own. Semi-automatic models require you to press a button, which takes a second or two but gives you a moment to make sure no one is touching the person. Both are acceptable; choose based on what feels less intimidating to you and the people who live with you.

For a workplace, semi-automatic is standard because it gives the user a moment to confirm the shock is appropriate. Look for a device with clear voice prompts, large buttons, and a carrying case. Some models are designed to be mounted on a wall; others are portable. If your workplace has multiple floors or a large footprint, you may need more than one device.

Check the warranty (usually 5 to 8 years) and whether the manufacturer offers training or support. Some companies provide free online training videos; others charge for in-person training. Factor that into your decision.

Training and maintenance: what you must do after you buy

Buying an AED is only half the work. Everyone who might use it—family members, coworkers, security staff—needs to know where it is and how to use it. This does not require a formal certification course, but it does require hands-on practice. Many AED manufacturers offer free or low-cost training videos on their websites. Some local fire departments or hospitals offer in-person AED training, often bundled with CPR training, for $50 to $150.

After you buy, you must check the device regularly. Most AEDs have a light or display that shows whether the battery and pads are in good condition. Check this monthly. If you have a device with a monitoring service, it will alert you automatically if something needs attention. Keep the device in a cool, dry place—not in direct sunlight or extreme heat, which can damage the battery.

If the device is ever used, the pads and battery must be replaced immediately, even if the device shows they are still good. After use, the device should be serviced by the manufacturer or a certified technician before it is put back into service.

Legal liability and what happens if you use an AED

If you use an AED on someone in cardiac arrest, you are protected by Good Samaritan laws in all 50 states. These laws shield you from legal liability if you act in good faith to help someone in a life-threatening emergency. You do not need to be trained to use an AED—the device talks you through the steps—but training reduces hesitation and improves the chance of success.

If you own a workplace AED, you are generally required to maintain it and ensure staff know where it is. Some states require workplaces above a certain size to have an AED on site; others do not. Check your state and local regulations. If your workplace is required to have an AED and does not, you may face fines or liability if someone has cardiac arrest and the device was not available.

If you own a home AED, there is no legal requirement to have one, and you are not liable if you choose not to buy one. If you do buy one and it fails to work properly, the manufacturer is responsible, not you—provided you maintained it according to instructions.

Alternatives to buying your own AED

If you are unsure whether a home AED is right for you, consider these alternatives. First, invest in CPR training for yourself and the people around you. CPR alone, without a defibrillator, improves survival rates and costs far less. Second, if you have a family member at high risk, talk to their cardiologist about whether a home AED is recommended for your specific situation—the doctor's opinion is more reliable than a general guideline.

Third, if you work in a building or area where an AED is already installed, make sure you know where it is and how to get it quickly. Many workplaces, shopping centers, and public buildings now have AEDs mounted on walls or in cabinets. Learning the location takes seconds and costs nothing.

Fourth, if you live in an urban or suburban area with short ambulance response times, the benefit of a home AED is smaller. Call 911 and start CPR—that combination saves more lives than a device sitting unused in a closet.

Frequently Asked Questions

Can I use an AED on a child?

Yes, but you need pediatric pads, which deliver a smaller shock appropriate for a child's smaller body. Most AED brands sell pediatric pads separately for $50 to $150. If you have a child at high risk of cardiac arrest, buy the pediatric pads along with the device. Some AEDs have a switch that lets you use either adult or pediatric pads on the same device.

What if I buy an AED and never use it—do I have to keep replacing the pads and battery?

Yes. Pads and batteries expire whether the device is used or not. If you buy an AED, you are committing to replacing pads every 2 to 5 years and the battery every 3 to 5 years. If you cannot afford this ongoing cost, do not buy the device. Some people choose to buy a device only if they have a family member at high risk and can justify the expense.

Is a home AED covered by insurance?

Most health insurance plans do not cover the cost of a home AED. Some employers offer AEDs as part of a workplace wellness program. If you have a family member with a high-risk heart condition, ask their cardiologist whether the device is medically necessary—in rare cases, insurance may cover it if the doctor writes a prescription. Otherwise, you pay out of pocket.

How long does an AED take to work?

From the moment you turn on the device to the moment it delivers a shock is usually 30 to 60 seconds. The device analyzes the heart rhythm, tells you whether a shock is needed, and delivers it if one is. During this time, you should continue CPR if the person is not breathing. The faster you get the AED and start using it, the better the chance of survival.

What should I do if someone collapses and I do not have an AED nearby?

Call 911 immediately and start CPR if the person is not breathing and has no pulse. CPR alone—chest compressions at a rate of 100 to 120 per minute—can keep blood flowing to the brain and heart until an ambulance arrives. Many 911 dispatchers can talk you through CPR over the phone. An AED is helpful if one is available, but CPR is more important and saves lives on its own.