Note from the Instructors: First quarter 2026 Coding Clinic update summary

by Shannon E. McCall, RHIA, CCS, CCS-P, CPC, CPC-I, CEMC, CRC, CCDS, CCDS-O, and Deanne Wilk, MPS, BSN, RN, CCDS, CCDS-O, CDIP, CCS

The fiscal year (FY) 2026 ICD-10-CM Official Guidelines for Coding and Reporting update, first quarter 2026 Coding Clinic guidance, and the April 2026 ICD-10-PCS additions (80 new codes, two deletions) include clarifications that refine existing guidance and introduce new procedure capture for advanced technologies. Below is a concise summary of the most impactful updates for coding professionals and CDI teams.

ICD-10-CM guideline updates

HIV coding: B20 versus Z21

This is one of the most substantial revisions this cycle with one new guideline and eight existing guidelines edited.

Assign B20, HIV disease, when:

• The patient has documented AIDS or HIV disease.
• The patient is being treated for an HIV-related illness.
• Any condition resulting from HIV-positive status is present.
• HIV disease is present even when the admission is for an unrelated condition (B20 may be secondary).

Assign Z21, Asymptomatic HIV status, when:

• HIV-positive status is confirmed but no HIV-related illness is documented.
• Patients on antiretroviral therapy (ART) with no documented HIV disease still use Z21.

CDI note: Query when a provider documents HIV alongside an AIDS-defining illness (e.g., PCP pneumonia, CD4 count <200) without using the word "AIDS." The provider does not need to say "AIDS." Documentation that a condition is attributable to HIV status is sufficient to support B20.

Hypertension with heart disease: Chapter 9

The update clarifies when I11, Hypertensive heart disease, requires an additional code versus when I11 alone is sufficient. A causal relationship between hypertension and certain cardiac conditions is presumed unless the provider explicitly states otherwise.

I11 plus additional code required:

• I50, Heart failure (any type)
• I51.4, Myocarditis, unspecified
• I51.89, Other ill-defined heart diseases
• I51.9, Heart disease, unspecified

I11 only, no additional code:

• I51.5, Myocardial degeneration
• I51.7, Cardiomegaly

Newborn observation encounters: Z05 (Chapter 16)

Code Z05 may be assigned as the principal diagnosis when a suspected newborn condition is evaluated and ruled out. This is especially relevant for newborn readmissions where Z38 (Liveborn) no longer applies.

• Use Z05 when a suspected condition is evaluated and not confirmed, meaning no diagnosis established.
• Do not use Z05 when a definitive diagnosis is established. Use the condition code instead.
• Z05 subcategories specify the type of condition evaluated (e.g., Z05.0 cardiac, Z05.3 infection, Z05.5 gastrointestinal).

Congenital conditions across the lifespan: Chapter 17

• Chapter 17 Q codes apply at any patient age when the congenital condition is clinically relevant including late diagnoses in adults.
• If a congenital condition has been corrected (surgically or otherwise), use the personal history code (Z87.7x) rather than the Q code.
• For birth admissions, Z38 is always sequenced first; congenital anomalies are additional diagnoses.
• Guideline correction: the code range reference was corrected from Q00–QA01 to Q00–QA0.

ICD-10-CM coding clarifications (first quarter 2026)

Hypothyroidism and dementia: Presumed relationship

ICD-10-CM presumes a causal relationship between hypothyroidism and dementia. No explicit provider linkage is required unless the provider states the conditions are unrelated. Sequence as:

• 1st (underlying cause): E03.-, Other hypothyroidism
• 2nd (manifestation): F02.80, Dementia in other diseases classified elsewhere

GLP-1 receptor agonists: Adverse effects and long-term use

Semaglutide, tirzepatide, and liraglutide are incretin mimetics not insulin or oral hypoglycemics. Specific coding rules apply.

Do NOT use T38.3X5A for GLP-1 adverse effects. The correct adverse effect code is T38.895A, Adverse effect of other hormones and their synthetic substitutes.

• Drug-induced pancreatitis: K85.30 + T38.895A
• Gastroparesis: K31.84 + T38.895A
• Long-term GLP-1 therapy: Z79.899 (no specific long-term code exists yet)

Starvation ketoacidosis

Seen in patients with eating disorders, post-bariatric surgery, or on GLP-1 therapy with suppressed appetite. Assign both the acidosis code and the underlying cause:

• E87.29 , Other acidosis (sequenced first)
• T73.0XXA, Starvation, initial encounter

CDI note: Query when a GLP-1 patient shows elevated anion gap, low bicarbonate, and near-normal glucose with poor oral intake. Full capture if GLP-1 attributed: E87.29 + T73.0XXA + T38.895A.

Cirrhosis etiology

When the underlying cause is documented, do not use unspecified K74.60. Pair K74.69 with the specific etiology:

• NASH: K75.81 + K74.69
• Chronic hepatitis C: B18.2 + K74.69
• Alcoholic cirrhosis: K70.30/K70.31 is a separate category, do not pair with K74.69

Acute kidney injury (AKI) etiology

When AKI has a documented cause, assign N17.8 with a separate etiology code. Use N17.9 only when the cause is undocumented. Common pairings:

• Rhabdomyolysis: N17.8 + M62.82
• Contrast nephropathy: N17.8 + T65.91XA
• Hypotension or cardiogenic shock: N17.8 + appropriate circulatory code

DIC with thrombocytopenia single code rule

When DIC and thrombocytopenia are both documented, assign D65 only. Thrombocytopenia is an integral manifestation of the consumptive process. Adding D69.6 is a coding error.

Exception: If the provider documents an independent cause of thrombocytopenia (e.g., ITP) distinct from DIC, that distinction must be clearly documented before adding a second code.

NSTEMI due to CABG graft complication: Sequencing correction

First quarter 2026 corrects the First quarter 2024 guidance. That prior advice answered a question about NSTEMI due to severe native multi-vessel disease (not a graft complication). When MI is directly caused by stenosis or thrombosis of a vein graft, ICD-10-CM classifies this as a complication of the prosthetic device. All codes are required:

• T82.857A, Stenosis of other cardiac prosthetic devices, implants and grafts, initial encounter
• T82.867A, Thrombosis due to cardiac prosthetic devices, implants and grafts, initial encounter (assign if thrombosis also documented)
• I21.A9, Other myocardial infarction type (Type 4b/5 MI)
• Either T82 complication code may be sequenced as the principal diagnosis; I21.A9 is an additional code.

Additional clarifications

• Acute myocarditis due to systemic lupus erythematosus (SLE): Assign M32.19 + I40.8. CDI query recommended when SLE patients present with cardiac symptoms not explicitly linked to SLE.
• Sepsis due to UTI: Assign A41.9, Sepsis, unspecified organism. when the organism is not documented. Sepsis is classified by the causal organism, not the infection source. A known infection site (e.g., UTI) does not support organism-specific sepsis coding without documented organism identification. See also Coding Clinic, second quarter 2020, p. 28.
• Low back pain laterality: "Left-sided low back pain" codes to M54.50 (unspecified), not M54.59. Laterality is not a type; ICD-10-CM classifies by nature of pain, not location.
• Ruptured ovarian cyst: Rupture describes an event, not a cyst type. Unspecified cyst codes apply (e.g., N83.201) unless the provider documents the type of cyst.
• North-south syndrome (VA ECMO): No unique ICD-10-CM code; assign T81.89XA (principal) plus manifestation codes per Guideline I.B.15. Query when providers document "differential oxygenation" or "upper body hypoxia on VA ECMO."
• Cesarean without current medical indication and false-positive HIV: Assign O82, Encounter for cesarean delivery without indication, when a C-section is performed based on a false-positive HIV screen later confirmed negative. The HIV was ruled out and cannot be coded as an indication. Assign Z71.7, HIV counseling, as an additional code for the negative HIV test result.
• Cesarean without current medical indication and history of shoulder dystocia: Assign O82 for elective cesarean based on prior history of shoulder dystocia, as there is no current obstetric complication. Assign Z87.59, Personal history of other complications of pregnancy, childbirth and the puerperium, as an additional diagnosis. Note: Prior cesarean delivery IS a valid current medical indication and O82 would not apply in that scenario.

ICD-10-PCS April 2026 additions

Effective for discharges April 1–September 30, 2026. The update introduces 80 new procedure codes and deletes 2, with no revised codes. Key additions by section:

Section 0—Heart/Great Vessels: Ventricular Septal Lead Placement

New insertion codes for pacing and defibrillator leads percutaneously placed into the ventricular septum (body-part value M). Coders must look for documentation specifying septal/interventricular placement to support correct body-part selection. Most common DRGs are in MDC 5 Circulatory. Note: Pacemaker "J" and cardiac lead "M" are classified as non-OR procedures.

Section 0—Urinary: Boari Flap and Ureteral Reconstruction

New table and codes for transfer of bladder tissue in ureteral reconstruction (Boari flap), addressing vesicoureteral reflux, ureteral trauma, and carcinoma. Maps to kidney/ureter MS-DRGs 656–661.

Section 0—Extraction of Omentum and Mesentery (Table 0DD)

Body part values U (omentum) and V (mesentery) were added with approach values 0 (open) and 4 (percutaneous endoscopic) to identify debulking and cytoreduction aspiration procedures performed on omental and mesenteric tumors. Example: 0DDV0ZZ, Extraction of mesentery, open approach, for ultrasonic aspiration (SONOPET®) removal of a mesenteric tumor in a patient with stage IVB endometrial cancer.

Section 0—Hepatobiliary: Endoscopic Biliary Drainage

20 new codes with qualifiers added to distinguish transmural (EUS-BD) from transpapillary (ET-GBD) endoscopic drainage approaches. This is a non-surgical procedure and does not affect MS-DRG assignment.

Section 0—Resection of Prostate with Intact Capsule (Table 0VT)

Qualifier value E (capsule intact) was added to body part value 0 (prostate) for approach values 0 (open), 4 (percutaneous endoscopic), 7 (via natural or artificial opening), and 8 (via natural or artificial opening endoscopic). This captures simple prostatectomy procedures where the prostate capsule is preserved. Example: 0VT04ZE for robotic-assisted simple prostatectomy with capsule intact. An additional code is required for robotic assistance. Maps to male reproductive MS-DRGs 707–708 and 713–714.

Section 0—Introduction of Embryonic Stem Cells (Table 3E0)

Substance value A (embryonic stem cells) was added for body part values 3 (peripheral vein) and 4 (central vein) via percutaneous approach. Embryonic stem cells are derived from the inner cell mass of a blastocyst and can differentiate into specialized cell types. Important: Embryonic stem cells are not cord blood and not blood products. As a result, codes 30233AZ and 30243AZ (transfusion of embryonic stem cells) were deleted from table 302 and are no longer valid. Does not affect MS-DRG.

Section 4—Measurement: Body Composition

One new code for air displacement plethysmography (ADP) to measure body composition non-invasively.  This is commonly used in NICUs and pediatric clinics to guide nutritional intervention. However, this technology can also be used for elderly patients as well as patients with disabilities. Does not impact MS-DRG.

Section 5—Extracorporeal: Doraya™ IVC Flow Regulator

New code for the temporary Doraya™ catheter, deployed percutaneously in the inferior vena cava below the renal veins to reduce central venous pressure in diuretic-resistant acute heart failure. Both an insertion and an assistance code are required. Maps to cardiovascular MS-DRGs 270–272.

Section F—Rehabilitation: Microcurrent Therapy and Expanded NPWT

New rehabilitation code for microcurrent stimulation (MENS/FSM), which delivers low-level electrical stimulation to promote tissue healing without visible muscle contractions. NPWT codes are also extended to thoracic and abdominal wound applications. Documentation must specify the modality. Maps to MS-DRGs 945–946.

Section X—ACSTERS (Fontan Procedure)

New code for the autologous cell-seeded, tissue-engineered resorbable scaffold (ACSTERS) used in the Fontan procedure for pediatric single-ventricle congenital heart disease. The scaffold is seeded with the patient's own cells, absorbed over roughly five months as vascular tissue grows in its place thus potentially eliminating reoperations as the child grows. Documentation must explicitly state the device is "autologous cell-seeded and resorbable" to support the Section X code.

Section X—Lumenless Defibrillator Lead (OmniaSecure™)

New Section X code for a small-diameter, lumenless, catheter-delivered lead supporting pacing, sensing, defibrillation, and cardioversion. Documentation must explicitly identify the lead as "lumenless and small-diameter" as device type cannot be inferred. If that specificity is absent, default to standard Section 0 lead insertion codes. Maps to circulatory MS-DRG 265.

Section X—New Therapeutic Introductions

• Anitocabtagene autoleucel (anito-cel): BCMA-directed CAR-T therapy for relapsed/refractory multiple myeloma. Code: XW0[3,4]31B. Affects MS-DRG 018.
• Alpha-1 proteinase inhibitor (Prolastin®-C): For hereditary AAT deficiency emphysema and steroid-refractory acute GVHD. Code: XW0[3,4]30B. No DRG impact.
• CPI-601 enzyme replacement therapy: For Batten disease CLN1, administered via intracerebroventricular infusion. Code: XW0632B. No DRG impact.
• DB-OTO gene therapy: Single intracochlear infusion for profound hearing loss due to OTOF gene variants. Code: XW0E33B. No DRG impact.
• Ellora temporary electromechanical dilation device: New obstetric Section X code for mechanical cervical/pelvic dilation device used during stage 1 labor. No DRG impact.

ICD-10-PCS coding clarifications

“Biventricular” Impella® devices

When an Impella® CP and Impella® RP are placed during separate operative episodes in the same hospitalization, assign 02HA3RZ twice—once per episode. This is not considered a biventricular configuration because the devices were not placed in the same operative session.

Personalized interbody fusion device

Device value "R" in the XRG table is reserved for custom-made, patient-specific interbody fusion devices (e.g., aprevo®) designed from the patient's own imaging data. Off-the-shelf devices marketed with terms like "customized fit" or "customized height" do not qualify. The descriptor was updated in FY 2024 to "Interbody fusion device, custom-made anatomically designed" to clarify this distinction.

Laminoplasty: Internal fixation device correction (second quarter 2015)

First quarter 2026 corrects an omission from second quarter 2015 laminoplasty guidance. The original answer was missing code 0PH304Z (Insertion of internal fixation device into cervical vertebra, open approach) for the graft plate used in swinging-door laminoplasty.

Per ICD-10-PCS Guideline B3.2.c, distinct objectives on the same body part require separate codes: the release (canal expansion), supplement (allograft), and insertion (internal fixation) are each distinct procedures requiring their own code.

Editor’s note: Wilk is the CDI director at ACDIS/HCPro. Contact her at deanne.wilk@hcpro.com. McCall is the director of HIM/coding for HCPro. Contact her at Shannon.mccall@hcpro.com.