Updated on: March 16, 2016

CMS Gets a Jump-Start on ICD-10 Coding Guidance and How it Differs from ICD-9

Original story posted on: May 30, 2013

Apparently it’s not too early for the Centers for Medicare & Medicaid Services (CMS) to begin addressing coding rules for the new ICD-10 system because it did just that in its May 16, 2013, Medicare FFS Provider e-News. It addressed the following in the ICD-10-CM diagnosis system: external-cause codes; reporting signs, symptoms, and unspecified codes; and dates of service (DOS). It also announced a few ICD-10-PCS updates. All of these topics are summarized below.


External-Cause Codes

Under the ICD-9-CM coding system, there is no national requirement for the mandatory reporting of external-cause codes, and there also will be no national requirement under ICD-10-CM.

Also not required is the reporting of the ICD-10-CM codes in Chapter 20, External Causes of Morbidity—unless a provider is subject to a state-based, external-cause code-reporting mandate or a particular payer’s whim. Naturally, if a new state- or payer-based requirement is instituted, that may change. According to CMS, “Such a requirement would be independent of ICD-10-CM implementation.”

Even if there is no mandatory reporting requirement, CMS encourages providers to voluntarily report external-cause codes because they provide “valuable data for injury research and evaluation of injury-prevention strategies.”

Signs, Symptoms, and Unspecified Codes

As coding professionals already know, specific diagnosis codes are reported when they are supported by the available medical record documentation and clinical knowledge of the patient’s health condition. Use of signs, symptoms, and unspecified codes is “acceptable, even necessary” in both ICD-9-CM and ICD-10-CM, says CMS. For example, if the physician has not determined a definitive diagnosis by the end of the encounter, codes for sign(s) and/or symptom(s) may be reported.

When a more specific code can’t be assigned because the clinical information provided isn’t sufficient, the appropriate unspecified code may be used (such as when a physician determines a diagnosis of pneumonia but not the specific type). These codes also may be reported when they most accurately reflect the patient’s condition during the specific encounter. However, always remember that, in all cases, the medical record documentation must support the code choice.


Dates of Service

This guideline seems rather straightforward, although physician practices have asked CMS to address the topic. Here’s the general rule: If the date of service (DOS) was before the October 1, 2014, implementation deadline, use the ICD-9 diagnosis code; if it is after October 1, use the ICD-10 diagnosis code.

However, depending upon your payer, you may not be able to use ICD-9 and ICD-10 codes on the same claim. You may have to submit two claims: one with the ICD-9 diagnosis codes and another with the ICD-10 diagnosis codes.

On the other hand, says CMS, “Some trading partners may request that ICD-9 and ICD-10 codes be submitted on the same claim when dates of service span the compliance date. Trading partner agreements will determine the need for split claims.”

Providers also must make sure that their systems, third-party vendors, billing services, and clearinghouses can handle both ICD-9 and ICD-10 codes depending on the DOS in the months following October 1, 2014.

In addition to clarifying the above for physician practices, CMS indicated that it would provide instructions in the future about how Medicare will handle DOS for inpatient settings before and after that date.

Future Code Updates

On the Diagnosis Side: CMS will create a 2014 ICD-10-CM and general equivalence mappings (GEMs) link in June after it receives the 2014 ICD-10-CM diagnosis files from the Centers for Disease Control (CDC). To download these files, go to http://cms.hhs.gov/Medicare/Coding/ICD10/index.html.  Note, however, that the CDC will not issue an update of the FY 2014 ICD-9-CM diagnosis addendum.

On the Procedure Side:


Disclaimer: Every reasonable effort was made to ensure the accuracy of this information at the time it was published. However, due to the nature of industry changes over time we cannot guarantee its validity after the year it was published.
Janis Oppelt

Janis keeps the wheel of words rolling for Panacea®'s publishing division. Her roles include researching, writing, and editing newsletters, special reports, and articles for RACMonitor.com and ICD10Monitor.com; coordinating the compliance question of the week; and contributing to the annual book-update process. She has 20 years of experience in topics related to Medicare regulations and compliance.