About ICD-10

The following is simply a transcript of our online “Introduction to ICD-10 For Dermatology” training video. Visitors are encouraged to watch the video instead of reviewing the following text. Doing so will provide a more thorough understanding of ICD-10 as it specifically relates to dermatology.

[Begin Transcript]

Let’s first take a step back and consider that some of you may be new to the field and might be completely unfamiliar with the coding process. So for those of you who are familiar with the basics, bear with us while we provide some background.

The ICD Codes

Ultimately, coding is simply the language that we use to provide a summary of the office visit charges to a patient’s insurance company. There are 3 types of codes which make up these charges. They include the evaluation and management (“E/M”) codes, the procedure codes, and the ICD codes.

The evaluation and management codes represent the complexity of the office visit.  The procedure codes tell insurance which procedures were performed. The good news is that both the “E/M” codes and the procedure codes will not change with the implementation of ICD-10. For example, new patients whose visits are normally a 99202 or 99203 will still be coded as a 99202 or 99203. Freezing a wart will still be charged a 17110, and so on.

Instead, it’s the ICD codes which indicate the diagnoses made (or at least those “addressed”) during a given office visit. It’s only the ICD codes that we need to be concerned with when the change occurs. Under the current ICD-9 code set, typical ICD examples would include 706.1 for Acne, 691.8 for Atopic Dermatitis, and 702.0 for an Actinic Keratosis. Those of you who have been working in dermatology for a while probably have these codes memorized by now.

ICD stands for International Classification of Diseases. In the United States, we’re currently using version ICD-9-CM. As the word international implies, the ICD codes essentially serve as a “universal language”. Its use allows diagnoses to be easily understood throughout the world, without language or cultural barriers getting in the way. In fact, the World Health Organization is the party responsible for the creation of the ICD codes.

The latest version, ICD-10, has actually been in use by most other countries since the 1990s, and it’s really just now that the United States has finally committed to join the rest of the world in its use.

Specifically, there are two versions of ICD-10 that will be implemented. ICD-10-CM deals with outpatient clinical diagnosis codes, which is what affects those of us working in dermatology. The “CM” stands for clinical modification, as it’s a version of ICD-10 which has been modified by the National Center for Health Statistics for use in the United States. It’s ICD-10-CM that we need to worry about.

You should also know that there is another version called ICD-10-PCS which will be implemented as well. However, it’s only for inpatient procedure codes, such as in hospitals.  So with very little exception, the average dermatology practice does not need to worry about ICD-10-PCS!

October 1, 2015

As the deadline draws closer, you will likely hear the date of October 1, 2015 repeatedly. The reason is because the U.S. Department of Health and Human Services (HHS) has issued the final rule mandating that everyone covered by the Health Insurance Portability and Accountability Act (HIPAA) must implement ICD-10 for medical coding effective October 1, 2015.

It will be interesting to say the least, because claims submitted on September 30, 2015 will still use ICD-9, and literally the next day forward (from October 1st on), ICD-10 will be mandatory. And therein lies much of the anxiety surrounding its implementation. There will not be a “transition” period in which we can optionally use ICD-9 after that date. If we get frustrated, or forget, and mistakenly code a visit using an ICD-9 code after October 1, 2015, the claim will not get processed, and we won’t get paid!

Why The Change To ICD-10?

Understanding the benefits if ICD-10 may help to ease the frustration that many of us are bound to feel during the transition. Although there are multiple reasons behind the switch, consider this… 

Epidemiologists study the patterns and causes of health issues within the population as a whole. By monitoring disease patterns, they can bring attention to diseases and conditions that deserve increased consideration by researchers, physicians, and health insurance companies, just to name a few.

For example, the incidence of melanoma has been increasing a lot in recent decades. Because epidemiologists have noticed this pattern, there has been an increase in research regarding the causes and treatments of melanoma.

As you can imagine, epidemiologists (and others – such as the insurance industry) would like to see detailed statistics on every disease and injury. Analyzing the ICD codes assigned by physicians throughout the country is the easiest and most efficient way of doing that. But epidemiologists don’t just want data – they want quality, specific data – and that’s where the problem lies with ICD-9.  Too many unique variations of diseases, conditions, or injuries share the same ICD-9 code.

For example, let’s say that researchers are studying a group of 1 million people in order to better understand the impact of psoriasis, and within that group, there are 30,000 patients who have been diagnosed with psoriasis. 

With ICD-9, that’s as specific as it gets – that is, that 30,000 people have been diagnosed with psoriasis.  That’s because all 30,000 patient visits share the exact same code – that being 696.1. The ICD-9 codes can’t differentiate one type of psoriasis from another.

But with ICD-10, those same 30,000 psoriasis diagnoses are broken down more specifically. ICD-10 might show that 23,000 people were diagnosed with typical Psoriasis Vulgaris (L40.0),  5,000 people were diagnosed with Guttate Psoriasis (L40.4), and the remaining 2,000 patients were diagnosed with Pustular Psoriasis on the hands and feet (L40.3).

Now, if you were a researcher trying to better understand the incidence of psoriasis and how it affects different groups within the population, which data would you prefer? That provided by ICD-9, or that given by ICD-10? Of course, the answer would be the more specific breakdown provided by ICD-10!

ICD-10 also greatly reduces what often seems to be completely illogical code sharing between totally unrelated diagnoses. For example, with ICD-9, even though Melasma and Solar Lentigines are two very different diagnoses, they both share the same code of 709.09. In fact, there are quite a few such “shared codes” in ICD-9.

With ICD-10, most (but not all) unique conditions or lesions have their own code. Using those same diagnoses as an example, Melasma has its own code of L81.1 and Solar Lentigines have their own code of L81.4.

And therein lies both the beauty and the frustration of ICD-10. It’s great for epidemiologists, insurance companies, and researchers. And there are even times when the added specificity will make the assignment of a diagnosis more logical for those of us on the clinical side. But with all of this added specificity comes a lot more codes. And guess who’s going to be responsible for choosing from amongst those codes? Most of the time, the answer will be ‘us’!

So let’s go over some of the key features that distinguish ICD-10 from ICD-9.

Key Features of ICD-10

The first we’ve already mentioned – and that is that ICD-10 will provide much greater detail than ICD-9. The “buzzword” that you’re likely to hear a lot over the next year is granularity. It’s a term that means “the state or quality of being composed of many individual pieces or elements”.

So again using the psoriasis example, consider how it’s coded in ICD-9. We only have the one code of 696.1 – that’s as specific as it gets. By contrast, in ICD-10, psoriasis is in the category of L40, which is then granulated (broken down”) into numerous individual subtypes such as Psoriasis Vulgaris (L40.0),  Guttate Psoriasis (L40.4), and Pustular Psoriasis on the hands and feet (L40.3), just to name a few.

In order to reflect this greater degree of detail, there’s no getting around the fact that many codes will be longer. Depending on the diagnosis, we’re talking up to six or (rarely) even seven characters! Fortunately though, in dermatology, the vast majority of codes are going to be in the 4-6 character range, with the longest typically being the neoplasm codes. For example, consider the ICD-10 code for Squamous cell carcinoma of the right eyelid which is code C44.122. At six characters long, it’s longer than anything we’re used to seeing in ICD-9!

And one of the reasons that the neoplasm codes are so long is because laterality (whether the lesion or condition affects the right or left side) will be indicated in certain ICD-10 codes. Let’s again consider the codes for SCC on the eyelid. The sixth character in the code for an SCC on an unspecified eyelid is ‘1’, while that of an SCC on the right eyelid is ‘2’, and one on the left eyelid is ‘9’. This is actually a common pattern seen throughout the ICD-10 neoplasm codes.

Another unique feature of ICD-10 is that certain diagnoses will need to be described using more than one code. Take the category of ‘Abscesses, furuncles, and carbuncles’ as an example. When coding for an abscess, we’re asked to also provide a code for the causative bacteria. 

On the contrary, we’ll also find that certain codes in ICD-10 will actually represent more than one diagnosis. These are called “Combination Codes”. They aren’t very common, especially when it comes to dermatology-related codes. When they are seen, it’s usually with respect to complication-prone, systemic conditions such as diabetes. For example, code E08.62 includes the description for both diabetes as well as skin complications resulting from the diabetes.

And another feature that ICD-10 brings us is that diagnoses can be marked as resulting from a preceding infection, injury, or illness. These are known as the “late effect” (“sequela”) codes.

For example, let’s say a patient comes in for their first visit and is diagnosed with Scabies. The code for Scabies infection is B86 – one of the rare 3 character ICD-10 codes that doesn’t break down into a more specific code. So the patient is treated, and now returns for follow-up 2 weeks later. At this point, they still have some residual pruritus, but they’re no longer infected. Because the previously used “B86” code represents an active Scabies infection, we should avoid using it. Instead, we would first code for pruritus (L29.8), since that’s the patient’s current symptom, and by adding the “late effect” code of B94.8, we can indicate that the pruritus is the result of the preceding Scabies infection.

Of course, the first thing that some of you might be asking is “Why are we using two codes?” Well, this is one of those situations first mentioned a moment ago, where two codes will be needed to describe the same condition or injury. We’ll go over this new requirement in greater detail in just a few minutes.

And the last of the features that we’re going to highlight with ICD-10 is that of greatly expanded coding that describes “situations and circumstances”. These would include times when a) a person who may not be sick comes in for a specific reason, or when b) circumstances influence a person’s health status, but those circumstances aren’t an actual illness or injury.

This code expansion won’t affect dermatology nearly as much as it will a few other specialties. But some examples of these types of codes would include describing a visit for skin cancer screening (Z12.83), post-op nurse visits (Z48.817), or even when someone has a personal history of melanoma (Z85.820).

We actually have those types of codes in ICD-9 already, but some examples of a few interesting new ones that we might occasionally use would include:

  • Something as simple as checking a patient’s blood pressure (Z01.30). Let’s say a patient who has a history of high blood pressure is asked to come in the day prior to surgery for a nurse visit to get their blood pressure checked. If no other code applies, then this one might come in handy.
  • There will now be a code to describe an “encounter for allergy testing” (Z01.82), which presumably might be used if your office does “patch” or RAST testing.
  • Another situation that occurs every now and then is when a child is diagnosed as having scabies or head lice, so their parents insist on bringing in their siblings for a screening. Assuming the siblings aren’t infected, then a code like Z11.8 Encounter for screening for other infectious and parasitic diseases would be the most appropriate.

Of course, only time will tell how practical (or should we say reimbursable) codes in this category prove to be.

The ICD-10 Index & Tabular List

All ICD-10 codes are officially found in two different documents provided to us by the National Center for Health Statistics. We say “officially” because there will, of course, be a number of aftermarket documents and software programs, such as those provided by the AAPC, Inga Ellzey, EMR vendors, etc.  Those aftermarket products should make things a lot more user-friendly. But that said, the official sources are:

The index is just as it sounds. It’s just like any other alphabetical index in the back of a book and provides a way of quickly referencing the various code categories. However, because the full listing of codes and instructions can only be found in the tabular list, we are advised to avoid using the index for final code selection. Instead, we are asked to use the index to tell us where we should look within the tabular list.

The tabular list contains the full, comprehensive listing of codes and includes all special notations and instructions. It’s broken into various chapters – most often based on general body system. For example, Chapter 12 is where we’ll find Diseases of the skin and subcutaneous tissue. You’ll also notice when you see the tabular list that all codes within a given chapter will begin with same letter. For example, all of the Chapter 12 skin disease diagnoses start with the letter “L”. 

If you don’t already have a copy, you can click either of the above blue links to download the latest PDF version.

As we get into the discussion about the instructions found within the index and tabular lists, there’s one point on which most of us will agree.  And that is that once ICD-10 is implemented, we will feel very fortunate that we work in dermatology!

The ICD-10 coding rules (which you will sometimes hear referred to as conventions) will affect everyone to some degree. In all honesty, though, those of us in dermatology will have it relatively easy. A number of other specialties – especially those that regularly deal with orthopedics, injuries, and chronic illness – will have it much harder.

But regardless of our specialty, when it comes to following these rules and conventions, it’s all about following the instructions! And ICD-10 involves a lot of instructions, so let’s go over the most common.

ICD-10 Instructions

The first of these are the Includes notes. The Includes notes generally provide clarification. A common scenario is when synonyms are provided for a given diagnosis. For example, when we’re looking up the various forms of alopecia, the Includes note for Androgenic Alopecia (L64) clarifies for us that the code includes the lay-term diagnosis of “male pattern baldness”. 

It’s the Excludes notes that can get somewhat tricky. There are two types, and there’s really nothing intuitive about how they’re named.

The so-called Excludes1 notes are there to tell us that we cannot code the listed diagnoses at the same time. For example, let’s say a patient is diagnosed with acquired epidermolysis bullosa (or “EB”). Well, patients either have acquired EB or they have congenital EB, but not both. So under acquired epidermolysis bullosa (L12.3), the Excludes1 note essentially reminds us that we cannot use the congenital EB diagnosis at the same time. In other words, “pick one or the other”. In this scenario, it makes sense. But just know that there may be times when the logic isn’t so clear as to why certain diagnoses are on a particular Excludes1 list.

On the other hand, the so-called Excludes2 notes are there to clarify that the listed diagnoses aren’t part of the represented code, and if applicable, can be made at the same time.

For example, for various acne diagnoses listed under the category L70, the Excludes2 note is there to remind us that the diagnosis of an acne keloid is not included in any of the L70 diagnoses, and if needed, we can list the code for acne keloid as well. In other words, it essentially tells us “if applicable, you can pick both”.

The See notes are self-explanatory and are something that anyone who has used an index in the back of a book would be familiar with. They simply “point you in the right direction”.

Let’s say you’re trying to select the correct code for a patient who’s got a rash from “poison ivy”. You know it’s a form of dermatitis, and that it’s allergic, so that’s where you look first in the index.

In doing so, you’ll find that the See note points you in the right direction, essentially telling you to first look under Dermatitis (you’re already there), but then look under Contact and then under Allergic – and that’s where you’ll likely find the code you’re looking for.

The See Also notes are a little different from the See notes.

A See Also note is most often used to provide alternative locations in the index where the most appropriate code might be found. The key word here is ‘might’. They’re simply presenting an alternative that you might want to consider, but it doesn’t necessarily mean that you’ll find the best code there.

For example, let’s say that the doctor you work with referred to a given lesion as a “papilloma”, so of course that’s where you look first in the index. The ICD-10 authors realize that the term “papilloma” may be used in a variety of diagnoses, some of which are more popularly referred to by another name. Therefore, the first thing you see when looking up the various types of “papillomas” is a See Also note.  It directs you to consider looking under Neoplasms, then Benign, and then “by site” if you don’t find what you’re looking for under Papillomas.

The Use Additional Code notes mean just as they sound.  We were given a preview of this a few minutes ago when discussing some of the key features of ICD-10. These notes instruct us that another code should also be used. It’s worth pointing out that, unless they’re presented as an option (with wording such as ‘if applicable’), then it will be required that we use the additional code!  Luckily, we won’t see them used too often in dermatology. If anything, we’re probably going to see the Use Additional Code notes most frequently when dealing with infections.

So let’s say a patient has “impetigo” (L01). At the top of the category, we’re told to “use an additional code to identify the infectious agent” – and the various “infectious agent” codes range from B95-B97.

The Code First notes are like the Use Additional Code notes, but with an added requirement. Code First notes instruct us that we must not only use an additional code, but also that the additional code should be listed first on the superbill.

The Code First notes are used most often to describe variations of a larger, often systemic disease. We won’t see them too frequently in dermatology, but an example would be with the L14 category of Bullous disorders in diseases classified elsewhere. Let’s say a patient has a “bullous” subtype of Systemic Lupus Erythematosus (SLE), in which the lupus is causing blisters throughout the skin. If we just use the diagnosis associated with SLE (M32.8), that doesn’t quite adequately describe the patient’s situation. Instead, what we could do is first (as we’re instructed by the Code First note), use the M32.8 code for SLE, and then add the L14 code (Bullous disorders in diseases classified elsewhere) to indicate that this patient is suffering from “bullous changes” as a result of their systemic lupus.

If there’s one of the new ICD-10 instructions that will make us thankful that we work in dermatology, the requirement to Add the appropriate 7th character to certain codes will be it!

For certain visits, a 7th character is required to provide “added details” about a given visit. Codes which require a 7th character are going to be very rare for us in dermatology, but they’re extremely common in the codes which describe injuries and accidents.

Depending on the practice setting, occasionally in dermatology we will repair accidental lacerations, so we’ll use that as an example. The code we’ll use is S01.01 (Laceration of the scalp without a foreign body). At the top of the category, we see instructions that say “The appropriate 7th character is to be added to each code from category S01” – and then describes how ‘A’ will be used if this is the initial encounter, ‘D’ will be used if this is a follow-up related to the laceration, and ‘S’ would be used if this is a “sequela” of the laceration. That is, the patient is being seen for something else besides the laceration, but which was caused by the laceration. For example, the patient is coming a few weeks later asking for pain medicine because of the associated pain, but the laceration itself has already been treated and is itself no longer an issue.

To keep it simple, let’s say that this is the initial visit. Well, we already stated that the base code we’re using is S01.01. But if we simply add the ‘A’ to the end, that only makes 6 characters, and they’re asking us to add a 7th character. That’s where the “placeholder X” comes in. Anytime we’re asked to extend out to seven characters, but simply adding the required additional character leaves us short of 7 characters, we’re supposed to use the letter ‘X’ to help make up the difference. So in this example, we would first add the letter ‘X’, and then add the ‘A’ as the 7th character which indicates that this is the initial encounter.  The final code would then be S01.01XA.

Can you imagine doing the billing for emergency rooms once these changes go into effect? We’ll be thankful that we won’t be dealing with the 7th character codes very often in dermatology, but when we do, we at least need to know how to handle them.

Punctuation Marks

There are a number of punctuation marks used within the ICD-10 Index and Tabular List. Their significance is usually easy to understand, especially when seen in context.

A few of the most common examples include:

  • ( ) Parentheses
    • Parentheses most often provide additional terms used to describe a given diagnosis. For example, in the Index, next to the term Dermatitis, we see ‘(eczematous)’. This is because some people will refer to dermatitis as “eczematous dermatitis”.  The parentheses are there to simply confirm that the term “eczematous dermatitis” would be coded as L30.9.
  • [ ] Brackets
    • Brackets are most often used to provide synonyms or explanatory phrases. For example, in the index, the brackets next to Benign Familial Pemphigus enclose its synonym – which of course is “Hailey-Hailey” disease.
  • Hyphens
    • Hyphens (or dashes) are used in a few different contexts in the Index and Tabular list. But their most significant meaning when referencing ICD-10 codes occurs with what is called a “point dash” (.-). The point dash is used to represent the more specific codes that exist following the decimal point of the listed category.  For example, in the Excludes2 note at the top of Chapter 12, we see that it lists “Viral Warts (B07.-)”. This essentially means that this Excludes2 rule would apply to the entire BO7 category of viral warts –  including all subtypes such as B07.0, B07.8, and so on.


And finally, there are some abbreviations you should be familiar with as well. The two most important abbreviations are NEC and NOS. They sound fairly similar, but their significance is actually quite different.

  • NEC
    • NEC means “not elsewhere classified”. It should be used to describe the rare circumstances when you have a specific diagnosis, but that diagnosis just isn’t found anywhere in the tabular listing. For example, consider a patient who is diagnosed with a rare deep tissue fungal infection (which is something we do occasionally see this in dermatology). The lab has confirmed the type of fungus, but it’s so rare that it’s not even listed anywhere within the tabular listing of infections. So after searching for that particular infection, we can’t find it, but we see that code B48.8 includes “Infections of tissue and organs by saprophytic fungi NEC”. In the end, this is the best code in this situation.
  • NOS
    • NOS means “not otherwise specified”. It all too often means that we aren’t able to provide further specificity for a given diagnosis. And because the whole point of switching to ICD-10 is to provide more specific diagnostic data, you can imagine that not providing the requested specificity can be a recipe for a rejected claim. For example, consider the L89 category of “pressure ulcers”. This is one of the categories in which the ICD-10 authors have gone to great lengths to list all of the various stages of the diagnosis.  Looking at all of the available options, how happy do you think Medicare or even a private insurer will be if we choose the option of “Healing pressure ulcer NOS”.  Doing so would be like telling insurance, “Yeah, it’s a pressure ulcer, but we didn’t stage it” or “Our documentation is so poor, that our coder can’t provide you with the stage”. The truth is that sometimes we simply won’t have a choice but to use one of the “not otherwise specified” codes. But just know that, when possible, we should try to avoid them when more specific codes are available.

Important Considerations For Staff

As you’ve probably figured out by now, ICD-10 coding will be associated with certain requirements that must be followed, or the claim will not get processed. If claims don’t get processed, cash flow comes to halt. Without the cash flow, none of us get paid. When it comes to what will keep dermatologists and their practice managers up at night, this is it. Everyone on staff within a given dermatology practice will need to be mindful of these requirements so that everything doesn’t grind to a halt when October 1st, 2015 arrives.

So if you remember nothing else about ICD-10, at least remember this…

We must code to the highest degree of available specificity! Remember, the added specificity that ICD-10 offers is the very reason behind the change in the first place!

Let’s use seborrheic dermatitis as an example, as it’s an incredibly common diagnosis in dermatology offices throughout the country. If we were to quickly scan through the tabular listing and see code L21 (where it clearly says “Seborrheic Dermatitis”) and think that we’re done, we’d be wrong. According to the new guidelines, the only time we’re allowed to leave the final code selection at the 3 character category code is if no subdivisions exist! If they do, then we must choose the final code from among those more specific codes.  In this example, those options would include L21.0 Seborrhea capitis, L21.1 Seborrheic infantile dermatitis, L21.8 Other seborrheic dermatitis, or L21.9 Seborrheic dermatitis, unspecified.

And just as the codes need to be more specific, the visit documentation must support the added specificity of the codes we use! This point cannot be overemphasized. With the widespread use of electronic medical records, physicians and other providers are relying increasingly on their staff to assist with documentation.

If a given ICD-10 code depends on whether a lesion was on the right or left side, then the notes must clearly indicate that. If, as previously cited, a patient has an infection and a specific bacteria has been identified, then the note must state that.

Most of you already know whether or not your office is in the habit of producing quality, thorough documentation. Just know that if you work in an office where the documentation is sparse, incomplete, or sloppy, then that’s going to have significant ramifications on how efficiently the appropriate codes can be assigned to each visit once ICD-10-CM implementation goes into effect!

And finally, all instructions provided to us within the tabular list must be followed! Examples include the Excludes1 notes, Excludes2 notes, Code First notes, Add The Appropriate 7th Character, etc.

We’ve already touched on these, but the point here is that 1) most of the instructions are not found in the Index – which is why we should always refer to the tabular list for final code selection, but also 2) the instructions they provide are not put there as suggestions – they are a requirement that must be followed for selecting the correct code!

Taking a cynical view, remember this…

Incorrect code selection (or sometimes even incorrect placement of those codes on the claim) will give insurance carriers a valid excuse to deny payment!

Again, it’s a bit cynical, but it stands to reason that the more excuses that there are to deny a payment, the more payments we’re going to see get denied. The best approach for us will be to follow the instructions provided, select the correct code, and (if applicable) place it in the correct order on the claim.  Doing so will avoid giving them an excuse to deny a claim in the first place!


AAD ICD-10 “Cheat Sheet”
Center for Medicare and Medicaid Services (CMS)
American Academy of Dermatology
Inga Ellzey Practice Group
ICD-9 to ICD-10 Conversion Tool
American Academy of Professional Coders (AAPC)