Understanding how 'and/or' works in ICD-10-CM coding and how it guides code selection.

Outline (skeleton for structure and flow)

• Hook: Coding language isn’t always black and white; “and/or” is a practical hint you’ll see often.

• What “and/or” really means: one or both conditions may apply; it’s not just “and” or just “or.”

• Compare and contrast: how and/or differs from “and” and from “or,” and why that matters in ICD-10-CM coding.

• A simple, concrete example: diabetes with two possible accompanying conditions, and/or dehydration.

• Why it matters in real-world coding: accuracy, billing, and the story the medical record should tell.

• Practical tips: how to read code descriptions, how to check the notes, and how to decide when to code one condition, the other, or both.

• Takeaway: and/or is a tool for completeness, not a trap.

What does “and/or” really mean in coding?

Let me explain with a straightforward picture. In ICD-10-CM coding, the phrase “and/or” isn’t a trick or a loophole. It’s a practical signal that helps you capture the patient’s full health picture. When a code description uses and/or, you have the option to code for one condition, the other condition, or both—depending on what the patient actually has. Simple as that. It’s about flexibility, not about creating confusion.

If you’ve ever wrestled with a description that reads like a math problem, you’re not alone. “And” says both conditions must be present for the code to apply. “Or” says either condition alone can justify the code. And/or sits in between, acknowledging that the patient may have one of the conditions, or both. It’s a small phrase with a big job: it guides the coder toward a complete, precise diagnosis story without forcing a choice that might not reflect the patient’s reality.

How and/or stacks up against and and or

• And: You need both conditions to be true for the code to be appropriate. It’s strict, like a double requirement.

• Or: Any one of the listed conditions would justify the code. It’s permissive, almost like a yes to either option.

• And/or: It’s a flexible middle ground. It says “one, or the other, or both.” This mirrors the real world, where patients often present with overlapping or concurrent issues.

The practical upshot? If the clinical notes show both conditions exist, coding one code for the first condition and a separate code for the second is perfectly acceptable. If only one is documented, you code that one. And in some cases, you’ll code both because the note supports both conditions. It helps ensure the medical record and billing reflect reality rather than a simplified caricature of it.

A simple, concrete example you can picture

Here’s a quick, tangible scenario: diabetes mellitus with ketoacidosis and/or dehydration. The note might indicate the patient has diabetes with ketoacidosis, dehydration, or both. What should you do?

• If the patient has both ketoacidosis and dehydration, you’d code for both conditions, using the appropriate diabetes code with the ketoacidosis modifier and a dehydration code.

• If the patient has diabetes with ketoacidosis but dehydration isn’t present, you code the diabetes with ketoacidosis only.

• If the patient has diabetes with dehydration but not ketoacidosis, you code diabetes with dehydration.

• If the notes aren’t clear on whether ketoacidosis or dehydration is present, you may need to review the record, ask for clarification, or code with the most supported single condition and mark the lack of clarity in the documentation trail.

The point is not to overthink a single line in a code description. It’s to read the clinical story in the notes and let and/or guide you toward the most accurate, complete combination of codes. The family of codes isn’t a rigid ladder; it’s a set of flexible tools that adapts to what’s actually documented.

Why this matters for your coding work

Accuracy matters because it affects patient care continuity and, yes, the billing flow. When you apply and/or correctly, you reduce the risk of undercoding (missing a condition) or overcoding (coding for a condition that isn’t supported by the notes). Both missteps can cause downstream headaches: denial of claims, audits, or a mismatch between what's in the medical record and what gets billed.

Here are a few real-world vibes to keep in mind:

• The record often contains a mix of phrases, multiple providers, and evolving diagnoses. And/or helps you reflect that ambiguity without forcing a premature verdict.

• The clinical scenario may change as new notes arrive. A patient who starts with dehydration only can progress to ketoacidosis; the coding approach should stay aligned with the evolving documentation.

• Coding for multiple related conditions can improve the specificity of the patient’s health status. That specificity helps researchers, payers, and care teams understand where the patient stood during that encounter.

Let me give you a couple of practical notes you’ll recognize in many ICD-10-CM descriptions

• It’s common to see “and/or” in the sense of “the patient has condition A, condition B, or both.” Your job is to mirror the patient’s actual state in the codes.

• The phrase often appears in descriptions that involve comorbidity or related risk factors. It’s a nod to real clinical complexity, not a gimmick.

• If the documentation is clear that only one condition is present, you don’t force the other into the code. But if both are documented, you’re not constrained to pick one—you can code both as appropriate.

A few practical ways to sharpen your reading

• Read the entire description, not just the first line. Sometimes the patient’s full story is in the context of the sentence or nearby notes.

• Check the clinical notes for explicit mentions of one or both conditions. If the record says “dehydration present” and “no ketoacidosis,” that matters for your choice.

• When in doubt, seek clarification or use the most precise codes supported by the documentation. The goal is to align with what was observed clinically.

• Cross-check with the guidelines: certain combinations may have specific coding rules or modifiers. The codes don’t live in a vacuum—guidelines exist for a reason.

A few tips you can apply now

• Build a mental habit: when you see and/or, pause and ask, “What does the chart actually show?” Then map it to the possible coding paths: one condition, the other, or both.

• Use simple language to verify with notes. If the chart says “A or B or both,” jot a quick line in your own notes: “A only? B only? Both?” This helps you stay on track when you’re coding.

• Practice with variety: look for descriptions in training materials that use and/or in different contexts—diabetes, hypertension, infectious diseases, and more. The more you see it, the more natural it becomes.

A quick recap, with a nod to real-life nuance

• And/or signals that one or both conditions may apply.

• It’s different from and (both) and or (either one) and should be interpreted in the context of the patient’s notes.

• The goal is accuracy and completeness: code the patient’s actual condition(s) as documented.

• Always check the clinical notes, verify with guidelines, and code for what’s supported—neither more nor less.

Takeaway: this is about clarity, not confusion

And/or isn’t a trick. It’s a useful, practical helper that keeps your coding honest and precise. When you see and/or in a code description, you’re being invited to capture the full health story: one condition, the other, or both. The result is a record that makes sense to clinicians, patients, and payers alike.

Question for reflection (a light nudge to keep you sharp)

In a scenario that lists diabetes mellitus with ketoacidosis and/or dehydration, how would you decide which codes to assign if the notes show both conditions? If only one is clearly documented, which path do you take? If the clinician notes both, how do you approach documenting both codes while staying within guideline boundaries?

As you work with real-world cases, you’ll notice and/or isn’t about clever wordplay. It’s about faithfully representing the patient’s health status so everyone—care team, coder, and payer—reads the same honest story. That shared understanding is what keeps documentation solid and the entire process moving smoothly. And that’s the aim we’re shooting for every time we sit down with a new coding scenario.