Don’t automatically presume a link between two conditions within a combination code in cases when a guideline requires that link to be explicitly documented, the latest version of ICD-10-CM coding rules clarifies.
For example, the ICD-10-CM guidelines cite the sepsis guideline for “acute organ dysfunction that is not clearly associated with the sepsis.” The change clarifies that code-specific documentation requirements take precedence over the more general “with” guideline, which appears in the coding conventions section at the front of the guidelines.
As before, in cases when the two conditions are not specifically linked by a relational term such as “with,” you also should not presume a link.
The change to the ICD-10 convention for “with” is just one of dozens you’ll find in the 2018 update to the ICD-10-CM Official Coding Guidelines. The new guidelines are due to take effect Oct. 1, along with hundreds of new diagnosis code changes.
The guidelines also added an additional linking term to look for – “in.” That means when you find the words “with” or “in” in an ICD-10-CM code descriptor, the alphabetic index or an instructional note in the tabular code list, you should presume a causal relationship between the two conditions linked by those terms unless instructed otherwise.
In addition, look for these noteworthy changes:
- For type 2 diabetic patients taking long-term doses of both oral hypoglycemic drugs and insulin, report only code Z79.4 for long-term use of insulin, according to a new guideline added to chapter 4. However, you should not assign that code when “insulin is given only temporarily to bring a type 2 patient’s blood sugar under control during an encounter,” the guidelines now state.
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Severity of substance use determines the remission code. Use an abuse in remission code when a patient has a mild substance use disorder and a dependence in remission code for moderate or severe substance use disorders. In addition, the guidelines for chapter 5 were revised to make it clear that substance use remission codes must be assigned based on the provider’s documentation “unless otherwise instructed by the classification.”
- New guidelines in chapter 2 separate “external beam” radiation treatment reporting from encounters for insertion of radioactive elements such as brachytherapy. If the encounter or admission is for external beam radiation therapy, report Z51.0 (Encounter for antineoplastic radiation therapy). However, if the encounter is for insertion of radioactive elements, report “the appropriate code for the malignancy” and do not assign code Z51.0, the guidelines instruct.
When a patient develops complications as the result of implant of radioactive elements, report first the malignancy, followed by the code appropriate to that complication (e.g., uncontrolled nausea, vomiting or dehydration).
- When a patient is diagnosed with type 2 myocardial infarction, myocardial infarction due to demand ischemia or secondary to ischemic balance, you should report new code I21.A1 (Myocardial infarction type 2) and include a code for the underlying cause, the guidelines state. Do not assign code I24.8 (Other forms of acute ischemic heart disease) for the demand ischemia, they instruct.
For diagnoses of myocardial infarction types 3, 4a, 4b, 4c and 5, report code I21.A9 (Other myocardial infarction type). In addition, make sure to follow the “code also” and “code first” notes “related to complications, and for coding of postprocedural myocardial infarctions during or following cardiac surgery,” the guidelines say.
- Guidelines for non-pressure chronic ulcers added. The new guidelines are no surprise in light of the introduction of 72 new non-pressure chronic ulcer codes. The new guidance for chapter 12 will be familiar to coders who work with the guidelines for pressure ulcers. For the most part the guidance simply replaces the term pressure ulcer with the term non-pressure ulcer.
- Fracture treatment guidance paradox resolved. An update to the pathological fractures section of chapter 13 clarifies that “Seventh character D is to be used for encounters after the patient has completed active treatment for the fracture and is receiving routine care for the fracture during the healing or recovery phase. The other seventh characters, listed under each subcategory in the tabular list, are to be used for subsequent encounters for treatment of problems associated with the healing, such as malunions, nonunions, and sequelae.”
Previous guidelines on the use of seventh character D (Subsequent encounter for fracture with routine healing) left coders scratching their heads because it appeared to instruct coders to use non-routine healing codes such as G (Subsequent encounter for fracture with delayed healing), for routine care of fractures.
- Post-abortion complications clarified. When a patient has retained products of conception following a spontaneous or elective abortion, select a code based on whether there were complications, new guidance for chapter 15 states. For example, when there are no complications following a spontaneous abortion, code O03.4 (Incomplete spontaneous, abortion without complication). Select an appropriate code from category O03 (Spontaneous abortion) or O07 (Failed attempted termination of pregnancy) when there are complications. In addition, codes from category O04 (Complications following [induced] termination of pregnancy) may be used to identify complications leading to an abortion, the new guidelines state.
- Additions to Z-code categories. You’ll find a scattering of additions to the various Z-code category lists in the new guidelines for chapter 21. For example, Z91.81 (History of falling) and Z91.82 (Personal history of military deployment) have been added to the “History of” list. Z40 (Encounter for prophylactic surgery) has been added to the list of Z codes that may be listed as the first diagnosis.