ICD-10 is coming. The scheduled date of arrival is Oct. 1, 2014, and there does not appear to be any potential for further delays. Although many organizations are preparing for the transition, it may still be too early for practicing physicians to try to become familiar with all the nuances of the new coding system. Until you're regularly using ICD-10, you probably won't retain what you've learned.

However, to be prepared, physicians do need to understand the following: 1) the basic changes inherent in the ICD-10 system and 2) how those changes drive the need for additional documentation details.

I have reviewed thousands of medical records over the past several years as a managed care medical director and clinical improvement consultant. This experience has led me to conclude that the overwhelming majority of current medical records, whether handwritten, dictated, or electronic, do not contain the necessary documentation to support the increased coding specificity required to properly use the ICD-10 system. That's the bad news.

The good news is that with a little effort you can get ready for what's coming, and this article will help.

An overview of the changes

The basic structure and coding rules inherent in ICD-10 may not be your idea of compelling reading, but bear with me. This brief overview will help you understand why your documentation will become more important under ICD-10.

Basic ICD-10 structure. An ICD-10 code consists of between three and seven characters. The first character is alpha. The second character is numeric. The third character is typically numeric, but the most recent updates to ICD-10 include some alpha characters in this position. These first three characters represent the category. For example, diabetes mellitus falls in the E00-E89 category of “Endocrine, nutritional and metabolic diseases.”

The fourth through seventh characters of an ICD-10 code appear after the decimal point and are either alpha or numeric. These characters reference etiology, anatomic site, and severity. Character seven is called an “extension.” Most of the exponential increase in the number of diagnostic codes under ICD-10 is related to these additional characters, as shown below:

• H10 Conjunctivitis,

• H10.0 Mucopurulent conjunctivitis,

• H10.01 Acute follicular conjunctivitis,

• H10.013 Acute follicular conjunctivitis, bilateral.

In this example, the first three characters (H10) describe conjunctivitis. The fourth and fifth characters describe the type of infection, and the sixth character describes the bilateral nature. Incidentally, if the conjunctivitis was the result of an external cause, you would have to add another code to identify that external cause.

Although it would be easier if the purpose of the fourth, fifth, and sixth characters remained the same from category to category, that is not the case. The use of these characters varies by category, as shown below:

• H54 Blindness and low vision,

• H54.1 Blindness, one eye, low vision other eye,

• H54.11 Blindness, right eye, low vision left eye,

• H54.12 Blindness, left eye, low vision right eye,

• H54.2 Low vision, both eyes,

• H54.4 Blindness, one eye,

• H54.41 Blindness, right eye, normal vision left eye,

• H54.42 Blindness, left eye, normal vision right eye.

Both of these code sets (H10 and H54) have options for the use of nonspecific codes. The H10 code set includes codes for “other acute conjunctivitis” and “unspecified acute conjunctivitis.” The H54 code set includes codes for “unqualified visual loss.”

The seventh character (the extension) is mostly found in two chapters of ICD-10. In the “Injury, Poisoning and Other Consequences of External Causes” chapter, it is used to describe the episode of care (A = initial, D = subsequent, and S = sequela). Fractures have even more options for the seventh character depending on whether they involve the Gustilo-Anderson classifications. (Explaining just the basics of fracture coding would take an entire article.) In the “Pregnancy, Childbirth and Puerperium” chapter, the seventh character is used to provide information about the fetus (1 = one fetus, 2–5 = two through five fetuses, and 9 = more than five fetuses).

If the base code is fewer than six characters but the code requires a seventh character, you would fill in the empty spaces with an x (e.g., S03.4xxA).

General coding rules. Common terminology is an important concept in ICD-10. In my experience, the following concepts are frequently misapplied even in ICD-9:

• “With unspecified complications” is a red flag for failure of the provider to document the complications,

• “With other specified complications” means the complication is specified but not contained in the ICD-10 manual,

• “Not otherwise specified (NOS)” is the equivalent of “unspecified.”

While it is tempting to use these nonspecific codes, perhaps including them on a superbill, physicians need to be aware of the risks inherent in doing so. I am aware of ongoing discussions among payers to focus audit efforts on providers who frequently use nonspecific codes. If you are using an electronic system that provides codes for you to choose from, be aware that the system may include an ICD-9 to ICD-10 translator and limit your options to the more generic four- or five-character ICD-10 codes. It will be important for you to ensure that the most specific code supported by the medical record is used for claim submission.

You are not required to code conditions that exist but are not relevant to the reason for the provided services. For instance, if providing care for a patient with diabetes mellitus, it is relevant to document the smoking status of the patient. If providing care for a patient with an acute ankle sprain, smoking status is likely not relevant.

Here are a few more common coding conventions you need to understand:

• “Code first” means the code is not an acceptable primary diagnosis code and another code should be in the first position,

• “Use additional” means certain situations require an additional diagnostic code,

• “Includes” and “excludes” are parenthetical commentary regarding similarly worded diagnoses that either fall within the code or are excluded from the code.

The need for better documentation

Coding in family physicians' offices generally takes place through one of three formats depending on the size of the practice and the use of electronic health records (EHRs). Solo and small practices often rely on a so-called superbill that contains a list of the most common diagnosis codes for the physician to check. Practices that use EHRs often incorporate an automatic billing system that translates the information from the record onto a CMS-1500 billing form. Larger practices often use coders to abstract the medical record and add diagnosis codes to claim forms.

In the first scenario, a one- or two-page superbill will not be enough to capture all the ICD-10 codes needed, so you will have to include specific documentation details to help with code selection that will likely extend beyond the superbill. In the latter scenarios, specific documentation will be required to help either the system or the coder translate a medical record into the most specific and correct ICD-10 code for the services. If the documentation is not specific enough, either the system will not perform properly or the coders will be forced to come back to you requesting additional documentation for them to properly code your claim and obtain reimbursement.

For an example of the level of documentation that will be required to support the new ICD-10 codes, see “Documenting diabetes mellitus under ICD-10.”

This increased specificity required in documentation may mean that physicians have to document details that seem obvious to them but would not be obvious to those abstracting the record for coding purposes. In fact, some of the documentation may seem silly, but remember that the individual doing the coding can only use what appears in the medical record. Even though your coder may understand what you meant, that will not satisfy an outside auditor or claims payer. In medicine, we often say, “If you didn't document it, you didn't do it.” In coding, we often say, “If you didn't document it, you can't bill for it.”

One example of this seemingly redundant documentation need is for obese patients. ICD-10 requires that the provider do more than simply document that a patient is obese. ICD-9 uses the code 278.00, “Obesity, unspecified,” but ICD-10 uses E66.0, “Obesity due to excess calories.” At the 2013 AAPC National Meeting, coders were advised not to use E66.0 unless the medical record specifically asserted excess calories as the cause for the obesity. Without that additional documentation, the coders would need to default to E66.9, “Obesity, unspecified.” This would increase the concerns noted above regarding the use of unspecified codes. For individuals using an EHR, this problem could be resolved in the template for documentation. For those providers creating handwritten or dictated records, it might be prudent to get in the habit of adding this additional verbiage to your documentation.

It is important for providers to understand the dramatically increased emphasis on coding that will occur in the near future and how hundreds of millions of dollars will flow through the Affordable Care Act as a result. If you work in an accountable care organization or other practice setting where the relative illness burden of your personal patients is calculated, more specific coding that leads to higher premium dollars for the payer may result in more dollars flowing to your practice to provide care for those individuals. Coding that does not capture the complete picture of all applicable diagnoses, comorbidities, etc., will result in fewer premium dollars to the payer and potentially fewer claims dollars to the provider.

This transfer of premium dollars based on risk adjustment will be one of the leading drivers for payers to audit providers who are using nonspecific diagnostic codes.

Don't panic

Yes, ICD-10 is coming and will not be stopped. And although the idea of having the number of diagnostic codes expand exponentially is scary, you can handle it. Many of the new codes are combinations of current ICD-9 codes; many additional codes simply specify right, left, or bilateral; and many other codes are for more complex conditions that are rarely seen in primary care. By learning the basics of the ICD-10 coding system, making some adjustments to your current written or dictated documentation, and ensuring that your EHR system can handle the required increased specificity of documentation, you will be ready to go when ICD-10 arrives.