Summary
The AAPC team has scoured the fiscal year (FY) 2027 ICD- 10-CM coding update — which includes 238 new codes, four revised codes, and 21 deleted codes — to bring you a comprehensive list of changes to prepare you for diagnosis coding beginning Oct. 1, 2026.
Neoplasm and Blood Disease
Secondary malignant coding will be more specific under ICD- 10-CM 2027, as the C78.- Secondary malignant neoplasm of respiratory and digestive organs and C79.- Secondary malignant neoplasm of other and unspecified sites codes are expanded. Currently, the Table of Neoplasms instructs you to report a secondary malignant neoplasm of the larynx, pharynx, or oral cavity with C78.39 Secondary malignant neoplasm of other respiratory organs.
Beginning Oct. 1, you will have three new codes to pinpoint the anatomical sites of these metastatic cancers more precisely:
- C78.31 Secondary malignant neoplasm of larynx
- C78.32 Secondary malignant neoplasm of pharynx
- C79.83 Secondary malignant neoplasm of oral cavity
There has also been a small but highly significant addition to the D50-D89 Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism codes. The inclusion terms for code D69.1 Qualitative platelet defects are deleted and reallocated to two new codes:
- D69.11 Glanzmann thrombasthenia
- D69.19 Other qualitative platelet defects
Tip
Under D69.11, you will now find Glanzmann’s disease and hemorrhagic and hereditary thrombasthenia, while Bernard- Soulier (giant platelet) syndrome, grey platelet syndrome, and thrombocytopathy will all be found under D69.19.
The last big change in oncology coding is in the D05.- Carcinoma in situ of breast codes. Currently, ICD-10-CM allows you to report a code from C50.- Malignant neoplasm of breast with a code from D05.-, as C50.- is subject to an Excludes2 instruction under D05.-. Beginning Oct. 1**, the Excludes2 instruction is an Excludes1. This means you will no longer report the two codes together if a patient is diagnosed with both conditions — you will only report a C50.- code in those circumstances.
Postprocedural Blood Sugar
Three new codes have been created for low blood sugar levels following surgery:
- E89.83- Postprocedural hypoglycemia following a procedure
- E89.830 Post bariatric hypoglycemia
- E89.838 Other postprocedural hypoglycemia
Cardiac Coding Changes
The FY 2027 ICD-10-CM revisions offer more specific descriptions for various diagnoses. For example, I42.0 Dilated cardiomyopathy will expand to I42.00 Dilated cardiomyopathy, unspecified, I42.01 Familial-genetic dilated cardiomyopathy, and I42.09 Other dilated cardiomyopathy.
Additionally, conditions often reported today under I42.8 Other cardiomyopathies or I49.8 Other specified cardiac arrhythmias will have distinct reportable codes, including:
- I42.81 Arrhythmogenic cardiomyopathy
- I47.22 Catecholaminergic polymorphic ventricular tachycardia [CPVT]
- I49.81 Brugada syndrome
- I49.82 Ventricular bigeminy
If the provider’s documentation doesn’t support any of these more specific codes, you have these options:
- I42.89 Other cardiomyopathies not elsewhere classified
- I49.89 Other specified cardiac arrhythmias not elsewhere classified
Odontogenic Sinusitis
ICD-10-CM adds odontogenic sinusitis diagnoses with the J34.83- Odontogenic sinusitis code subcategory. You’ll use a 6th character to identify which sinus is affected by the condition (maxillary, ethmoid, frontal, or sphenoid sinus). Use J34.839 Odontogenic sinusitis, unspecified for cases of the condition where the physician didn’t specify which sinus was affected.
New K Codes
FY 2027 ICD-10-CM adds K31.B Hypertrophic pyloric stenosis, in childhood. You’ll also see the addition of K6A.- Diseases of the pelvis, not elsewhere classified with the following codes:
- K6A.0- Pelvic abscess
- K6A.01 Prevesical abscess
- K6A.09 Other pelvic abscess
- K6A.8 Other diseases of the pelvis, not elsewhere classified
Tip
Also added: K74.0A Hepatic fibrosis, moderate fibrosis and K76.83 Intestinal failure-associated liver disease.
Skin Condition Codes
There is one new code this year related to skin and subcutaneous tissue, L02.237 Carbuncle of flank, which necessitated three code revisions:
- L02.232 Carbuncle of back [any part, except buttock and flank]
- L03.312 Cellulitis of back [any part except buttock and flank]
- L03.322 Acute lymphangitis of back [any part except buttock and flank]
Plantar Fasciitis and Fibromatosis
FY 2027 ICD-10-CM adds M67.A- Plantar fasciitis with the following codes:
- M67.A0- Plantar fasciitis, foot
- M67.A01 Plantar fasciitis, right foot
- M67.A02 Plantar fasciitis, left foot
- M67.A09 Plantar fasciitis, unspecified foot
For plantar fascial fibromatosis (M72.2-), there are three expanded code options:
- **M72.**20 Plantar fascial fibromatosis, unspecified foot
- M72.21 Plantar fascial fibromatosis, right foot
- M72.22 Plantar fascial fibromatosis, left foot
Osteomyelitis
The M86.8X- Other osteomyelitis codes are expanded, allowing you to specify not only the body part but also laterality. You will need to choose a 7th character to identify whether the affected anatomical structure is unspecified or is on the right or left side of the body.
You’ll also need a 7th character for M86.8X8- Other osteomyelitis, other site to identify which structure is affected, such as:
- M86.8X80 Other osteomyelitis, skull
- M86.8X81 Other osteomyelitis, face and sinuses
- M86.8X89 Other osteomyelitis, other site
Another new M code, M04.3 VEXAS Syndrome, was created for reporting a serious autoinflammatory condition that typically begins in adulthood and is characterized by the immune system targeting the body’s own tissues.
N&O Codes
New subcategory code N99.86- Intraoperative and postprocedural complications and disorders of breast includes the following codes:
- N99.860 Intraoperative and postprocedural nipple ischemia
- N99.861 Intraoperative and postprocedural nipple necrosis
In Chapter 15: Pregnancy, Childbirth, and the Puerperium, ICD-10-CM adds 56 new codes for ectopic pregnancies, including:
- O00.12- Interstitial ectopic pregnancy without intrauterine pregnancy
- O00.13- Interstitial ectopic pregnancy with intrauterine pregnancy
- O00.3- Cesarean scar ectopic pregnancy
- O00.4- Cervical ectopic pregnancy
- O00.5- Cornual ectopic pregnancy
New code O31.4- Continuing pregnancy after vanishing twin syndrome of one fetus or more includes the following:
- O31.40- Continuing pregnancy after vanishing twin syndrome of one fetus or more, unspecified trimester
- O31.41- Continuing pregnancy after vanishing twin syndrome of one fetus or more, first trimester
- O31.42- Continuing pregnancy after vanishing twin syndrome of one fetus or more, second trimester
- O31.43- Continuing pregnancy after vanishing twin syndrome of one fetus or more, third trimester
*Each of the codes listed above requires a 7 th character to identify the fetus for which the code applies.
Q Codes for Frequency of Use
There are several new codes being added to the congenital malformation section as follows:
- Q87.A Loeys-Dietz syndrome
- QA1 Genetic disorders associated with neoplasms, not elsewhere classified
- QA1.7 Inherited neoplasm predisposition syndromes involving multiple systems, not elsewhere classified
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- QA1.71 Lynch syndrome
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- QA1.79 Other inherited neoplasm predisposition syndrome of multiple systems
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- QA1.71 Lynch syndrome
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- QA1.790 Familial cancer syndrome with pathogenic BRCA1 mutation
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- QA1.791 Familial cancer syndrome with pathogenic BRCA2 mutation
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- QA1.792 Li Fraumeni syndrome
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- QA1.798 Other inherited neoplasm predisposition syndrome of multiple systems
Note: The “A” is added to track the use and frequency of this code.
Atypical Gadolinium Levels
Under subcategory code R78.7- Finding of abnormal level of heavy metals in blood, you’ll find new code R78.72 Abnormal gadolinium level in blood.
Toxic Effects
There are several additions to the toxic effects codes, starting with T52.81- Toxic effects of alkenes. You will have to choose 6th and 7th characters for T52.81-, as you will with most of the other toxic effects codes in ICD-10-CM. The 6th character identifies the intent of the toxic exposure (accidental, intentional self-harm, assault, etc.). The 7th character identifies encounter type for the injury.
The new toxic effect code subcategories for FY 2027 are:
- T52.82- Toxic effects of cycloparaffins
- T52.89- Toxic effects of other organic solvent
- T59.82- Toxic effects of hexamethylene diisocyanate
- T65.85- Toxic effect of medetomidine
Info
With the addition of T52.89-, codes T52.8X- through T52.8X4S are no longer needed and are being deleted effective Oct. 1.
More Specificity Means More Sensitivity
In Chapter 21: Factors influencing health status and contact with health services (Z00-Z99), you’ll find a mixed bag of changes.
Changes to body mass index (BMI) codes offer greater specificity. In FY 2026, Z68.1 Body mass index [BMI] 19.9 or less, adult captured the entire adult BMI range at or below 19.9 in a single code, but in FY 2027 that code splits into Z68.18 Body mass index [BMI] 18.4 or less, adult and Z68.19 Body mass index [BMI] 18.5-19.9, adult.
Other new codes include:
- Z77.013 Contact with and (suspected) exposure to gadolinium
- Z77.32 Contact with and (suspected) exposure to burn pits in war theater
- Z77.33 Contact with and (suspected) exposure to Agent Orange
- Z77.4- Contact with and (suspected) exposure to blast overpressure
- Z86.17 Personal history of Clostridioides difficile infection
The FY 2027 update also offers more specificity and greater sensitivity in reporting changes to patients’ sex and gender by expanding Z87.890 Personal history of sex reassignment to include:
- Z87.8901 Personal history of social gender transition
- Z87.8902 Personal history of medical gender transition
- Z87.8903 Personal history of surgical gender transition
- Z87.8904 Personal history of intersex surgery
- Z87.8909 Personal history of unspecified gender transition
- Z87.893 Personal history of gender detransition
This article does not cover every change in the FY 2027 ICD- 10-CM update. For a more comprehensive overview, don’t miss AAPC’s webinar on the “ICD-10-CM Updates for 2027,” scheduled for September 16. Register at AAPC.com/medical-coding-education/webinars.
Resource: www.cms.gov/medicare/coding-billing/icd-10-codes
NOTE
This article was originally posted online, June 12, 2026, in Revenue Cycle Insider. Subscribe online for more articles like this, as well as other specialty-specific articles.