Pediatric Coding Alert

Understanding why codes are sequenced is key, say experts.

Instructions telling you how to sequence multiple ICD-10 codes are plentiful and distributed throughout ICD-10’s general and chapter-specific guidelines. On the surface, that seems both intimidating and the potential cause for numerous coding errors.

So, we reached out to two experts and asked them for their best advice about ICD-10 sequencing, and here’s what they had to say.

Understand the Etiology/Manifestation Rule

“Of all of the coding use that is bound by sequencing guidance, pediatric coders most often encounter codes that have notes on abiding by the etiology/manifestation convention,” says Jan Blanchard, CPC, CPMA, pediatric solutions consultant at Vermont-based PCC. 

This is addressed in guideline 1.A.13. Basically stated, ICD-10-CM requires you to sequence the underlying condition first “if applicable, followed by the manifestation.” 

“These are the ‘code first,’ ‘use additional code,’ and ‘in diseases classified elsewhere’ notes you see in the Tabular section of ICD-10,” Blanchard notes. “‘Use additional’ is the requirement that the underlying condition be sequenced first followed by manifestation(s),” Blanchard adds. 

Clinical examples: Perhaps the most familiar examples of this sequencing rule to pediatric coders occur in the otitis media (H65-H67) codes. Here, you are required to use additional codes for such underlying conditions as exposure to environmental tobacco smoke (Z77.22), exposure to tobacco smoke in the perinatal period (P96.81), and tobacco use (Z72.0) among other underlying causes for Nonsuppurative otitis media (H65.-) and Suppurative and unspecified otitis media (H66.-) — if they are applicable.

The otitis media in diseases classified elsewhere codes (H67.-) can be both manifestations and primary condition codes. So, they carry instructions to code first the underlying diagnosis, such as plasminogen deficiency, coded to E88.02, or a viral disease not elsewhere classified (B00-B34). And, along with the Nonsuppurative otitis media codes, the H67 codes can also be primary diagnoses with an associated condition: a perforated tympanic membrane, coded to H72.-.

Pro coding advice: “Watch for ‘code also’ and ‘code first’ instructions to help with sequencing,” says JoAnne M. Wolf, RHIT, CPC, CEMC, coding manager at Children’s Health Network in Minneapolis. “But remember, ‘code also’ just instructs that more than one code may be needed to fully describe the patient’s condition. The sequencing is going to depend on the circumstances of the encounter, as stated by guideline I.a.17,” Wolf adds.

Pay Attention to Pre-Op Sequencing

One other guideline you should pay special attention to, according to our experts, is I.C.21.c.16. That’s because “pre-ops need to be sequenced properly to avoid denials. They should be sequenced as: Z01.81- [Encounter for preprocedural examinations] as first-listed diagnosis per the guideline, the reason for the need for surgery as second diagnosis, and any chronic conditions that affect patient care for additional diagnoses. I believe several payers have edits that incorporate this guideline,” Wolf cautions.

Use This Tip to Help Keep it All Straight

“Stick with the very basics of ICD coding: index first, then tabular,” says Blanchard. “So long as you always consult the tabular section of your ICD-10 manual when using a new-to-you code, you’ll never wonder if you’re working with a code for which sequencing rules need to be applied. Make sure to review pairs of ‘Use additional code’ notes at the etiology code, and ‘Code first’ notes at the manifestation code to ensure proper sequencing order in the guidance,” Blanchard adds.

This could mean selecting the discouraged “Unspecified” option when needed, Blanchard continues. “A number of the M00.- [Pyogenic arthritis] codes, for example, are either combination codes that specify the infectious agent or have the instructions to use an additional code to identify the bacteria causing the infection. But when a clinician was able to assess and treat the patient without the culture, and did not have an organism to accurately cite, the much maligned unspecified code M00.9 [Pyogenic arthritis, unspecified] was perfectly fine for the encounter,” Blanchard notes.

Last, Know Why Sequencing Is Important

Clinically, of course, there are good reasons to follow the sequencing guidelines. “The code sequence paints a hierarchical picture of the patient’s condition, as the underlying causes and relationship(s) between diseases and symptoms are expressed by way of the codes’ place in the lineup,” Blanchard points out.

From a coding perspective, this also means listing the most specific diagnosis codes first. So, with our otitis media example, if a patient also complains of fever, you would list the H65-H67 code before R50.9 (Fever, unspecified) as the H65-H67 has the highest level of specificity.

But as is so often the case in medical coding, there are also financial stakes attached to the guidelines. “Correct sequencing avoids denials and sometimes assures maximum benefits for the patients. Although many diagnosis codes can be included on a claim, some payers will only look at the first diagnosis code or the first few listed diagnosis codes when assigning benefits,” notes Wolf.

This means sequencing “grows ever more important as more and more carriers assign complexity scores to patients covered by value-based care plans,” Blanchard concludes.