What Does NOS Mean (Medical Abbreviation)?

When you look at your medical records, medical bills or other official documents from a doctor’s workplace, you might see the abbreviation “NOS” somewhere. This might seem frightening, however it has a very basic description. Here’s what “NOS” suggests in the medical context, and what that might imply for you. Besides as a medical abbreviation, NOS has other meanings such as brand-new old stock in retail and auction market.

What does NOS Mean as a Medical Abbreviation?

“NOS” simply means “Not Otherwise Specified.” It’s an abbreviation that assists doctors pick from a standard list of codes that inform the diagnosis of your medical condition. Most of the times, a standard list has really specific codes that cover almost everything. But your condition might be something that isn’t really specified because list, therefore your doctor chooses “NOS” instead.

For example, you might have a stress and anxiety condition. There are many particular sort of stress and anxiety disorders, but what if yours does not fall within any of those pre-set codes? Your doctor would pick “Anxiety NOS” which implies “stress and anxiety condition, not otherwise specified.”

Another example might be knee pain. If you experience knee pain, you might go to the emergency room, then be sent to have x-rays or other work done. They can’t discover the cause, and inform you to subsequent with your doctor. In the meantime, they need to go into a code for your insurance company. Since they can’t specify what caused the knee pain, they may use the term “Arthralgia NOS,” which indicates “joint pain, not otherwise defined.”

Examples of NOS as Medical Conditions


PDD-NOS is one of the 3 autism spectrum conditions. This one in particular is “prevalent developmental condition not otherwise specified,” which is also referred to as atypical autism. This is because the symptoms do not quite fit the other medical codes or descriptions for the condition.


“Personality condition not otherwise defined” refers to those who have concerns with character conditions, however nothing that fits nicely into any designated code. Other personality conditions specified are sadistic character condition, depressive personality condition, passive — aggressive personality condition and self-defeating personality condition.


“Mood condition not otherwise defined” indicates that there is something wrong, but the medical diagnosis codes provided don’t do justice to the issue. Hence the MD-NOS is filed. Bear in mind this is not a medical diagnosis, however rather simply a method of filing a code that fits an approximate diagnosis.


Common consuming conditions consist of anorexia, bulimia, and others that have ended up being a part of mainstream lexicon. But there are a number of eating conditions that don’t fit neatly into those classifications, therefore there is “eating condition not otherwise defined.”


This classification implies “depressive condition not otherwise specified,” which suggests that somebody has a form of anxiety that is hindering their day-to-day life, but it doesn’t fit into any of the routine codes for insurance coverage or diagnostic purposes.

What Are Other Meanings of NOS?

Though medical uses are some of the most common reasons you might see NOS, there are other uses for the phrase too. These expressions might be extremely commonly used, or they may be obscure. We have consisted of numerous of them here; nevertheless, remember that this is not an extensive list. There could be other uses of “NOS” abbreviation that are not consisted of here.

1. New Old Stock

A really typically used phrase in the retail and auction service, this means products being marketed that were made a very long time back, and therefore aren’t really ‘brand-new.’ This can describe obsolete devices, or parts for that obsolete equipment. That old stock might represent all that is available of that particular product, even though it was manufactured several years ago.

A good example of this is an old typewriter that needs a ribbon and ink, as well as strips of correction paper. These items might not be produced on a broad scale any longer, however there might be “old stock” that was produced several years ago that is still for sale. As you might imagine, this term is a very common one for those who are interested in antiques, vintage cars and so forth.

2. National Occupational Standards

This represents standards of efficiency that are used in the United Kingdom. These are lists of expectations for work, including the understanding and skills a person needs in order to perform a job to the best of their ability.

3. In Information technology

On the planet of information technology, acronyms and abbreviations are typical. “NOS” is used more than as soon as in this field, and may suggest “network os.” It might likewise mean “Nokia OS,” which is an os for Nokia cellular phone, or a kind of software called “NOS,” which is an operating system for the Control Data Corporation Cyber, a line of mainframe computer systems.

4. In Science

The abbreviation “NOS” also has a location in the world of science. Lots of people may acknowledge it has actually a shortened form of “Nitrous Oxide,” which is typically used in racing engines. It is likewise referred to as “nitrous” and has been used typically in pop culture movie that involves racing cars. It also means the lesser-known “nitric oxide synthase,” which is a class of enzymes. “NOS” can also be used as an acronym, such as for the “National Ocean Service” (part of the National Oceanic and Atmospheric Administration) and the “National Ornithological Society,” which is a society for bird-watchers.

To puts it simply, the term “NOS” can be found nearly anywhere. But if you find it in your medical files, you might be worried. It is necessary to keep in mind that “not otherwise defined” in a diagnosis or billing code is nothing to stress over, and merely indicates that the medical literature or billing codes don’t include your specific condition, or that your doctor hasn’t determined precisely what is going on yet. In either case, “NOS” is no reason for worry.

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Add a comment

  1. Riley

    That is simple!
    Not Otherwise Specified
    Within ICD-9-CM, you may pick codes specified as “Not Otherwise Specified” (NOS) when there isn’t really adequate paperwork to pick a more certain code. In other words, a shortage in documentation stops you from coding to a greater level of uniqueness.