The FY 2027 ICD-10-CM code files were posted in early June by the CDC's National Center for Health Statistics and CMS: the tabular and index tables, the addenda, the conversion table and the present-on-admission exempt list. The update applies to dates of service from October 1, 2026 through September 30, 2027. The coding guidelines for FY 2027 had not been posted as of this writing; they usually follow within a few weeks.
By count, this is a moderate year. The update adds 190 new billable codes (about 238 new entries once the new category and subcategory headers are counted). Four code titles are revised, and roughly 30 codes lose billable status, most of them because they gained more specific children and became headers. Chapter 19 (injury and poisoning) sees the most additions, around 60, followed by Chapter 15 (pregnancy) with around 44 and Chapter 13 (musculoskeletal) with around 31. For a typical office practice, a dozen or so of the new codes will matter, and a few of them will matter a great deal.
Key takeaways
- Plantar fasciitis gets its own codes (M67.A01 right, M67.A02 left, M67.A09 unspecified) after years of sharing M72.2 with plantar fascial fibromatosis.
- Z68.1 splits into Z68.18 (BMI 18.4 or less) and Z68.19 (BMI 18.5 to 19.9), which matters for malnutrition and frailty documentation.
- I42.0 becomes a header; dilated cardiomyopathy now needs a fifth character.
- Run your 12-month diagnosis frequency report against the deleted and demoted list before September.
- Teach the ten codes your specialty will use, not the 190.
The codes most practices will use
| Area | New codes | Who cares |
|---|---|---|
| Plantar fasciitis | M67.A01 right foot, M67.A02 left foot, M67.A09 unspecified foot; M72.2 subdivided for plantar fascial fibromatosis with laterality | Podiatry, orthopedics, primary care, physical therapy |
| Low body mass index | Z68.18 (BMI 18.4 or less, adult) and Z68.19 (BMI 18.5 to 19.9, adult) replace Z68.1 | Primary care, geriatrics, oncology, fracture care |
| Dilated cardiomyopathy | I42.00 unspecified, I42.01 familial or genetic, I42.09 other; I42.0 becomes a header | Cardiology, internal medicine |
| Osteomyelitis | M86.8X- expanded by site and laterality | Orthopedics, infectious disease, wound care, podiatry |
| Secondary malignancy sites | C78.31 larynx, C78.32 pharynx, C79.83 oral cavity | Oncology, ENT |
| Platelet disorders | D69.11 Glanzmann thrombasthenia, D69.19 other qualitative platelet defects | Hematology |
| Continuing pregnancy after vanishing twin | O31.4- series by trimester and fetus (33 codes) | Obstetrics |
| Hepatic fibrosis staging | K74.0A for stage F2 fibrosis, distinguished from F1 | Gastroenterology, hepatology |
| Post-bariatric hypoglycemia | E89.83 codes (two) | Endocrinology, bariatric surgery |
| Odontogenic sinusitis | J34.83- codes with a sixth character for the sinus | ENT, dentistry-adjacent practices |
| Exposure history | Z77 codes for burn pit emissions, Agent Orange and blast overpressure | Practices serving veterans |
| Toxic effects | T52.81 alkenes and T52.82 cycloparaffins, each with the standard seventh-character set (12 codes each) | Emergency and occupational medicine |
Plantar fasciitis is the headline for office practices. Until now it has been coded to M72.2 (plantar fascial fibromatosis, or Ledderhose disease), which describes a different condition and carries no laterality. From October 1, a right-foot plantar fasciitis has its own code, and payers with laterality edits will expect it. Note that there is no bilateral code in the new subcategory; bilateral disease is coded with both the right and left codes. Practices that see heel pain should expect M72.2 on a post-October claim to draw questions, because it now means fibromatosis and nothing else.
The BMI codes matter for a different reason. Z68.1 has covered BMI 19.9 or less as a single code; the split at 18.5 matches the CDC and World Health Organization definition of underweight, which supports malnutrition, frailty and osteoporosis documentation and, in Medicare Advantage risk adjustment, may affect how those conditions are captured. Code BMI only when the associated diagnosis (malnutrition, underweight, an eating disorder) is documented by the provider; the BMI code alone is not a diagnosis.
The cardiomyopathy and secondary malignancy additions follow the logic of most of this year's update: a condition that was coded to a single unspecified or "other" code gains children that name the type or site. For cardiology, I42.0 splits into unspecified, familial or genetic, and other, and coders should expect to use the genetic code only when the documentation supports a familial or genetic cause. For oncology, C78.31, C78.32 and C79.83 let a metastasis to the larynx, pharynx or oral cavity be coded to the site rather than to a broader category, which matters for registries and for payer policies that list covered secondary sites.
What it does to a favorites list: a worked example
Take a four-provider podiatry and orthopedic foot and ankle practice that billed M72.2 about 2,100 times in the past 12 months, nearly all for heel pain. On October 1, every one of those encounters needs a different code, and the choice depends on documentation the providers have not been writing: which foot. Two of the four providers document laterality in the assessment; two write "plantar fasciitis" and rely on the exam section.
| Step | What the practice does in September |
|---|---|
| Frequency report | Confirms M72.2 is the practice's fourth most-used diagnosis, 2,100 encounters |
| Mapping decision | M72.2 stays only for true fibromatosis; heel pain maps to M67.A01, M67.A02 or both |
| Favorites list | M67.A01 and M67.A02 added at the top of the heel pain group; M67.A09 deliberately left off the list so unspecified is a conscious choice |
| Template | Assessment template adds a required laterality field for heel pain diagnoses |
| Payer check | Two payers' injection policies list M72.2 as a covered diagnosis for 20550; the practice asks both whether M67.A- is loaded for October 1 |
| Provider session | Twenty minutes, three codes, the payer answer, and the template change |
The payer check is the step that saves the most money. A payer that has not updated its policy list by October 1 will deny 20550 with M67.A01 as not meeting criteria, and the practice will be appealing correctly coded claims for two months. Asking in September, in writing, gives you either the answer or the evidence for the appeal.
Deletions and conversions
The codes that lose billable status include I42.0 (now a header), Z68.1 (replaced by the two new codes), the S23.420 sternoclavicular sprain series and a handful of others expanded into more specific children. The conversion table lists each deleted code and its replacements. Run your practice's diagnosis frequency report for the past 12 months against the deleted and demoted list; any code you used more than a handful of times needs a mapping decision before October, and your EHR favorites, order sets and superbills need the new codes loaded.
The September checklist
- Load the FY 2027 code set in the EHR and practice management system as soon as your vendor releases it, and confirm the effective date logic: a September 30 visit must still code under FY 2026, and an October 1 visit under FY 2027. Systems that switch on install date rather than date of service produce rejections in both directions.
- Rebuild provider favorites lists. Replace any deleted code, and add the new specific codes for conditions your providers document often. This is also the moment to remove unspecified codes from the top of the list.
- Update paper superbills and any charge capture templates. Practices that still use paper are the ones we see billing deleted codes in November.
- Check payer medical policies that list covered diagnoses. A policy that lists M72.2 for a heel pain injection may not yet list M67.A-; payers lag, and you want to know which ones before you bill.
- Read the FY 2027 guidelines when they post and circulate the changes to coders. Guideline changes are where the audit findings come from next year.
- Schedule a 30-minute session with providers in late September on the codes that affect their specialty. Ten codes, not two hundred.
What we would not do
We would not try to train coders on all 190 codes. Most of the toxicology, obstetric and rare-disease additions will never appear in a given practice. Pick the ten that will and teach those well. We also would not wait for the guidelines to start the EHR work; the code files are final, and the guidelines rarely change how a code is built into a favorites list.
Our medical coding team loads the annual update for the practices we code for and reviews each specialty's favorites in September, and the coding courses include an annual update session. Rates are on the pricing page.
Questions we hear
Do the new codes affect claims for dates of service before October 1?
No. Date of service governs. A claim for a September visit submitted in October uses FY 2026 codes.
Is there a grace period?
Not for Medicare, and not in our experience for most commercial payers. Claims with a deleted code on or after October 1 reject at the clearinghouse or deny at the payer.
Where is the official list?
On the CMS ICD-10 page and the CDC's ICD-10-CM page, under the FY 2027 files: the addendum lists every addition, deletion and revision, and the conversion table maps deleted codes to their replacements.
What to do this month
- Download the FY 2027 addenda and conversion table and file them with the download date.
- Run the 12-month diagnosis frequency report and mark every code on the deleted or demoted list.
- Pick the ten new codes that matter for each specialty in the practice.
- Ask your EHR and practice management vendors for the code set release date and confirm the date-of-service logic.
- Write to the payers whose policies list a code you are about to stop using, and keep the answers.
- Put the late-September provider session on the calendar now.
