What Is A Code 4? Firefighter Radio Codes And When They Are Used

What Is A Code 4 Firefighter Radio Codes And When They Are Used.

They have a set of radio codes that will let them communicate complex, important information in a fast and standardized fashion. 

But, what do these codes mean, and what are they? We will walk you through this today. 

A code 4 means that no further assistance is needed, and it is used as a radio code amongst the emergency services.

This communicated to other responding resources, such as the fire, police, and ambulance services, to let them know that they can cancel their response and direct their attention to any other emergencies. 

The fire services have moved away from many of the radio codes that were previously used, however there are some that are still commonly used. We are taking a look at the codes that are still used, their meanings, and their variations depending on location. 

Emergency Services Codes- Are they standardized? 

In the United States of America, the highest level of emergency service codes are indeed standardized.

That means codes 1 through 4, which are used, specifically, in order to describe the manner of response that will be required by an emergency response vehicle when it responds to an emergency call. 

Therefore, it dictates the urgency of the matter and whether things like lights and sirens should be needed when they are responding to a call.

These are not the same, as we shall go over soon, as the priority terms which are ranked in order 1 to 5, which are codes used by Paramedics and Emergency Medical Services. It is easy to get these two confused. 

What is Code 1?

A Code 1 response is known as a cold response, this means that it is the lowest type of priority call, the response vehicle will likely head to the incident without any lights or sirens as there is no reason to employ these. 

This does not mean that the call is pointless or that the incident will likely be abandoned in favor of a more pressing issue. Instead, it simply means that there is no requirement for a high-speed, high-intensity response to this incident.

In simple terms, this is used when there is a routine, or scheduled transportation of non-emergency patients. 

What is Code 2?

A code 2 is different to a code 1, but it is still a form of a cold response, which is employed when there is a non-life-threatening emergency at hand that requires an immediate response but without the use of red lights or a siren. 

In some cases, a code 3 might be downgraded to a code 2 when a first responder arrives on the scene and determines the issue is not as urgent as originally believed. 

Similar to a code 1, this does not mean that the call is treated as unimportant, it is just that there is no need for the emergency services to rush to the scene and risk their own safety, or that of the general public by doing so. 

Understanding Code 3

A code 3 is what is known as a ‘hot response’, and in this scenario you would expect an emergency vehicle running a code 3 to have their lights on and their siren on. This is a response to a call that is deemed to be life-threatening and an emergency.

It is important that a medical response team get to the scene as fast as is humanly possible, in order to effectively respond to the call and hopefully save a life. 

It is possible for a code 2 to be upgraded to a code 3 if the situation requires it. Codes 3 and 2 can be upgraded or downgraded depending on the severity of the situation. 

Code 4 meanings 

In the situation where there are enough responders on the scene of the incident then there is no need for any further vehicles to be called, then the code may be a code 4. This is an instruction to discontinue the call as it is being sufficiently dealt with. 

However, it is worth noting that when examining the radio code policies of different departments within the United States, not all of them will allow for a code 4 use, and some will only employ codes 1 to 3. 

This is why it is important for any firefighter to be completely accustomed to their local policies before calling in a code 4, because there are possible risks of being misleading or confusing their colleagues by using it if it is not used in their department or state. 

Priority Terms

Firefighter radio codes

Priority terms are a set of non-universal terms which are employ by some medical service agencies and paramedic teams, And as this is so, there are some that may carry over into the world of firefighting, as a majority of firefighter are also fully qualified paramedics (bet you didn’t know that, did you?) 

It is important not to confuse these with the radio codes we already mentioned. These are what we are referring to. 

Priority 1

DOA (Dead on Arrival Trauma/CPR.

This signifies that the victim is deceased.

Priority 2


Explanation to the hospital that there will be an urgent need for support upon arrival.

Priority 3


Occasionally, paramedics will respond to calls that do not require emergency treatment, however the patient will need to be transported to the hospital regardless. 

Priority 4

Situation Under Control.

A signal that no further action is needed for the patient.

Priority 5

Mass-Casualty Incident.

This may seem like it could be the least priority, however, it is actually extremely serious and warrants that the hospital dispatch need to be notified that there may be many patents on the way and may potentially all require emergency treatment. 

National Incident management System, and Shifting to Plain Language 

The USA has been examining the practical use of radio codes for a long time, and there is certainly a case for the use of plain language in radio communication in modern times. 

Codes were useful when radio quality was not as high performing, but today, this is not an issue anymore, and even smartphones are capable of providing high-quality ‘push to talk’ radio signals. 

It is said that, “it is required that plain language be used for multi-agency, multi-jurisdiction, and multi-discipline events, such as major disasters and exercises.” 

This basically means that when there is more than one emergency service involved, plain language is needed, and actually, back in 2006, it was ensured that any federal grants given for these operations required that plain language be used too. 

It has also been recommended that individual agencies adopt using plain language. However, since this piece of writing exists, you can tell that this recommendation has not quite made it to being taken up universally yet. 

This is a shift that is meant to replace the codes seen above, and the use of 10-codes in interagency usage, however, it does not prohibit the use of 10-codes in any single agency usage. This may explain why the 10-codes are the best known of all of them. 


So, what are 10-codes? Well, they are not actually 10-codes at all, they are ten signals, although they are not called that by many. They are considered to be brevity phrases that allow law enforcement and other services to communicate effectively with one another with ease and speed. 

However, they often lack standardization of any kind, and they can vary from department to department. This can make 10-codes among some of the most confusing codes that are used in the USA.

Many feel that they should simply be replaced by plain language and in 2012, ACPO International, mandated a transfer to plain speech when using the radio. 

This, of course, has not been entirely successful. However, many states have phased out 10-codes, and they are not as common as they once were, but they are not entirely gone yet. 


10- 55 is the ultimate example of why 10-codes are being phased out. They are being phased out simply because they are confusing, which the 10- 55 code is. 

In some places a 10- 55 code is used to refer to those who have died and are past the point of being saved, simply chest compressions won’t work, a hospital won’t work, and the situation is beyond salvageable. This is also often referred to as a ‘coroners case’ for obvious reasons. 

While it may mean this in some areas, in many others a 10- 55 will refer to an intoxicated driver, and so if someone hears a 10- 55 and is in a jurisdiction different to their own, the meaning could be totally different and therefore problematic to those who are trying to sort the situation. 

We can agree that there is really no better reason out there to replace these with simple, plain English, is that these codes are just plain confusing. 

No one wants to respond to a situation only to find out the situation was completely different to what they initially thought it was because the code means something different somewhere else. It is just unnecessarily confusing. 

Wrapping up

Whether you hope to work as a firefighter, or another member of the emergency services, or if you are just interested, we hope that our guide has helped.

We hope that this has given you a better grasp and insight into firefighter codes and emergency responses within the United States, as well as an understanding of their meanings. 

Be aware that these are not always used, and there may be times, and probably will be more times, when they are simply better off being replaced by ‘plain language’ or ‘plain English’ (especially those ten codes!) 

So, regardless, if you want to work as a firefighter, or in the emergency services, do check what coding systems are in place at your department before you put your knowledge into practice.

The odds are you are all good to go, but it is better to be safe than sorry as we are sure you will agree, so check just in case, you do not want to get it wrong and end up in… hot waters.