Revenue Cycle Insider

Hint: The use of a combo code can provide a lot of context.

Coders may feel confident selecting and reporting primary diagnoses in the outpatient setting, but navigating coding guidelines to report additional diagnoses can get a bit hairy.

Here are some tips from Brett Randolph, RHIT, CDIP, CCS, vice president of client services at HIAcode, which he shared in his AAPC’s HEALTHCON 2025 presentation “Coding Clinic Advice’s Impact on Reporting Additional Diagnoses in the Outpatient Setting.”

Navigate Coding Chronic Conditions in Present Encounters

The ICD-10-CM coding guidelines used to instruct coders to code all documented conditions that coexist, but the guidelines have evolved. Organizations like the American Hospital Association (AHA) have offered clarifications, but sometimes those interpretations made things more confusing for coders.

According to the third quarter 2021 AHA Coding Clinic^® for ICD-10-CM/PCS: “Coding professionals should not assign codes based solely on diagnosis noted in the history, problem list and/or a medication list. It’s the provider’s responsibility to document the chronic conditions affecting care and management of the patient on that encounter.”

So, if a patient has diabetes listed in their past medical history but comes in for a different concern, you can report diabetes only when the provider documents it as a current condition that is relevant to this encounter (for example, evaluated, monitored, treated, or otherwise affecting care/management). “We know that they’re typically taking those conditions into consideration, depending on what conditions the patient has,” he said. It’s important that the physician documents their thought process there, as that supports reporting of the diabetes diagnosis for that encounter.

“It’s really important to make sure that if you see something in your history of present illness or your past medical history, your medication list or your problem list, it’s got to be clarified somewhere else from the physician that the patient still has this condition. ‘The patient’s being treated for this condition or that.’ [The physician] took this condition into consideration when he’s prescribing other things for this patient,” Randolph said.

Remember the Rules for Code Also

There are many situations where patients have multiple conditions or their diagnosis requires multiple codes to report it most fully. In these situations, an ICD-10-CM code may have a Code also instructional note to guide coders to describe the other condition(s), which can help when deciding what’s appropriate to report.

Code also notes do not include any sequencing direction; instead, the sequencing depends on the circumstances of the encounter, Randolph said.

For example, if a patient is diagnosed with insomnia due to a mental disorder, the insomnia code may include a Code also note instructing you to report the associated mental disorder, so both conditions are fully described.

It’s crucial to establish or maintain the habit of looking at your code book. “Really paying attention to your code book and not just looking up a code — looking to see: Is there other information in here that’s telling you the ‘with’ guidelines, the Code also guidelines, the Use additional? Any of those guidelines you can pull from the other areas in the record,” Randolph said.

Understand the Why Behind ‘With’

The preposition “with” shows up frequently in ICD-10-CM coding guidelines too, and it can give you some guidance when deciding what conditions are appropriate to report, or when deciding how to report some situations involving multiple diagnoses.

The guidelines say that “with” or “in,” when appearing in a code title, the Alphabetic Index, or Tabular List, should be interpreted as “associated with” or “due to.” Seeing “with” means framing the associated conditions as having a causal relationship when you find the term.

Important: When you see these terms in a code title, the Alphabetic Index, or the Tabular List (when the classification links the conditions), you may code the conditions as related even if the provider doesn’t explicitly state the relationship as being causal. The guidelines say: “These conditions should be coded as related even in the absence of provider documentation explicitly linking them, unless the documentation clearly states the conditions are unrelated or when another guideline exists that specifically requires a documented link between two conditions.” However, if the classification does not link the conditions, then a provider must explicitly document the relationship for you to report them as related.

Considering the diabetes example again: If a patient is seen for a kidney condition such as chronic kidney disease (CKD), and type 2 diabetes is also documented as current, a coder may look to E11.22 (Type 2 diabetes mellitus with diabetic chronic kidney disease). Because the classification links diabetes and kidney manifestations using “with,” the conditions may be coded as related unless the documentation clearly indicates they are unrelated or another guideline requires an explicit link. Also report the CKD code(s) from category N18.- (Chronic kidney disease (CKD)) as needed to specify stage, based on the Tabular instructions for the diabetes/kidney code selected. If the kidney condition is not documented for the encounter, it should not be added based on assumption alone.

Rachel Dorrell, MA, MS, CPC-A, CPPM, Production Editor, AAPC