ICD-10-CM changes: What physicians need to know before Oct. 1

Every October, physicians hear some version of the same message: ICD-10 is changing, and physicians need to pay attention. That can make the annual update sound like another administrative task added to an already long list, but physicians don't need to memorize hundreds of new codes. What matters is understanding whether the changes affect the conditions they treat and, more importantly, whether their documentation captures the clinical detail needed to support accurate coding.

For FY 2027, the Centers for Medicare & Medicaid Services has added 190 new diagnosis codes, deleted 30, and revised four. While that is a smaller update than last year's, the number of changes isn't the point. Some revisions introduce greater specificity, change coding guidance, or alter how certain diagnoses are classified for reimbursement.

For physicians and practice leaders, the more useful question is: Is my practice prepared to document and code these changes correctly when they take effect on October 1?

Start with the changes that affect the practice

Physicians do not need to review all 190 new codes. Instead, start by finding out which changes apply to the practice's specialty and patient population. The FY 2027 update includes new codes and greater specificity in areas including maternal-fetal medicine, oncology, cardiology, toxicology and several other clinical areas. A physician who rarely encounters these conditions may have little reason to change documentation habits. Others may find that seemingly small changes meaningfully affect how diagnoses are reported.

However, when a new code requires greater specificity, the code itself is not the difficult part. Ensuring that the medical record contains the clinical information needed to support that code is. For example, a code may distinguish among anatomical sites, disease characteristics, underlying causes or other clinical details. If that information is clinically relevant, it needs to be documented clearly enough for the coder to assign the appropriate code.

The FY 2027 changes are reminders that specificity matters.

Physicians should continue to document the diagnosis they establish, along with the clinical details that distinguish it from similar conditions when those details are known and relevant. That may include the site, acuity, etiology, stage, laterality or other characteristics of a condition, particularly important when a more specific code becomes available.

The best approach is to document what is known clinically rather than trying to anticipate a particular code. Physicians should not change their clinical terminology to obtain a particular reimbursement result. Instead, the goal should be to make the medical record an accurate representation of the patient's condition. When documentation is clear, the coding process has a much stronger foundation.

Pay attention to changes in coding guidance

Not every important ICD-10 change involves a brand-new diagnosis. Some FY 2027 changes affect how existing diagnoses are reported. Changes to coding guidelines and Excludes1 and Excludes2 instructions, for example, can affect whether certain conditions may be reported together. A new hypertensive crisis category and related guideline information also take effect.

For physicians, the takeaway is simple: if their billing or coding team says a documentation practice needs to change because of the new code set, ask why. Understanding the clinical information they need can prevent repeated questions later. This can also help practices distinguish between a legitimate request for clarification and an unnecessary documentation burden.

Ask the EHR and billing team whether the systems are ready

Physicians and practice managers should not assume everything will work automatically on October 1. The practice's EHR, billing platform, coding tools, problem lists, templates, and other systems that rely on ICD-10-CM need to be updated and tested. This is primarily an operational responsibility, not something physicians should have to manage themselves. But they should know who owns it.

If guidance is needed, ask the billing or practice management teams whether the FY 2027 code set has been loaded and tested. If the practice relies on an outside billing service, ask the same question.

It is also worth asking whether any payer-specific edits or medical policies are expected to change. A practice can document and code an encounter correctly and still encounter a claim problem if a payer's systems are not prepared for the new code set.

Understand that coding can affect more than the claim

ICD-10-CM codes are used for more than claim submission; they can influence quality reporting, risk adjustment, medical necessity determinations, analytics and other processes that depend on coded clinical information. Some FY 2027 changes also affect complication and comorbidity classifications, including new CC and MCC designations.

Physicians do not need to understand the mechanics of those classifications. They should understand that accurate, specific documentation can have consequences beyond whether a single claim is paid. That makes good documentation valuable for both the patient record and practice operations.

Practice leaders can ask their coding or billing teams to review a sample of records in areas affected by FY 2027 changes. If the review identifies recurring documentation gaps, physicians can receive targeted education before those gaps begin affecting claims.

The same principle applies after implementation. Practice leaders should monitor coding questions, claim denials, payment delays, and other indicators during the first several months after October 1. A review at 30, 60 and 90 days can help spot patterns and determine whether additional education or workflow changes are needed. The objective is not to turn physicians into coding specialists. It is to catch problems early, before they become routine.

The annual ICD-10 update does not need to become another major administrative burden for physicians. The most important preparation is straightforward: understand which changes affect the specialty, talk with the coding and billing teams and make sure documentation captures the clinical information those teams need.

For FY 2027, the question is not whether a physician can name all 190 new codes. It is whether the practice is prepared to translate clinical care into accurate documentation and coding when the new code set takes effect.

Physicians provide the clinical story. Coders translate that story into standardized codes. Billing teams and technology carry those codes through the revenue cycle. When each part of that process is working from accurate, complete information, an annual ICD-10 update becomes much less disruptive.

And that is the goal: not simply being ready for a new code set, but making sure the record accurately reflects the care being provided.

Leigh Poland, RHIA, CCS, CDIP, CIC, is Vice President of Coding Services, Clinical Quality and Education at AGS Health.