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Z79.4 ICD-10-CM Code: Long term (current) use of insulin

Compare with another codeCheck this code on a claim

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Tabular directives
1 inclusion term · 5 Excludes2 · 2 code-also instructions
Risk adjustment
CMS-HCC V28: 1 category · CMS-HCC V22 category 19 · RxHCC V08 category 31

Billable · FY2027A valid, specific ICD-10-CM code, reportable for dates of service in FY2027.

What you need to know

Source: CMS/NCHS Official ICD-10-CM tabular notes, quoted. From the CMS/NCHS tabular list for the release in force. A note the category or block publishes applies to this code too; the Instructions section marks which is which.

Code alsoMay be needed with this code
  • any therapeutic drug level monitoring (Z51.81)
  • any follow-up examination (Z08-Z09)
Excludes2Not included here; may be reported together
  • long-term (current) use of injectable non-insulin antidiabetic drugs (Z79.85)
  • long term (current) use of oral antidiabetic drugs (Z79.84)
  • long term (current) use of oral hypoglycemic drugs (Z79.84)
  • drug abuse and dependence (F11-F19)

+1 more in Instructions

IncludesWhat this code covers
  • long term (current) drug use for prophylactic purposes

Most relevant related codes MedCoder-derived

Read off the official notes above and this code’s own position in the tabular list. Which to report is a documentation question; Compare shows the two side by side.

CompareCheck ClaimView Related Codes

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v44, Appendix B.

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Risk Adjustment (CMS-HCC)

Payment categories this diagnosis maps to under CMS-HCC V28, payment year 2026.

  • HCC 38 — Diabetes with Glycemic, Unspecified, or No Complications

Other models: CMS-HCC V22 HCC 19 · RxHCC V08 HCC 31

Risk scores depend on the enrollee's full accepted diagnosis set and segment; a category mapping alone does not determine payment.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for Z79.4 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2027Effective: October 1, 2026

Trace:FY2027 changesChange historyRelease, file and checksum

Notes without a marker are published on Z79.4 itself; “inherited from” names the category or block whose note applies here.

Includes

Conditions the official ICD-10-CM tabular list includes under this code.

  • long term (current) drug use for prophylactic purposes

Source: inherited from Z79

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

Code Also

Additional codes that may be required to fully describe the encounter.

  • any therapeutic drug level monitoring (Z51.81) inherited from Z79
  • any follow-up examination (Z08-Z09) inherited from Z77-Z99

Coder workflow for Z79.4

MedCoder structured workflow — derived from this code’s own official record

Before you code Z79.4

  1. Confirm the reason for the encounter this Z code records: the circumstance it records. Check whether the code may be reported as first-listed or principal — some Z codes are limited to one position — and do not report a history or status code for a condition documented as current. Z code categories and their reporting positions (Guidelines I.C.21.c, I.C.21.c.15).

    Guide: Z codes as principal or first-listed diagnosis →

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
The reason for the encounter
Whether the code records the encounter’s purpose, a status, or a history — and whether it may be first-listed (Guidelines I.C.21.c).

Official instructions as workflow

  • Excludes2 — not part of Z79.4(5 notes)

    Coding workflow: The conditions named in this note are not included in Z79.4. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

    CompareZ79.85, Z79.84, O99.32

    See the official tabular notes · Guidelines I.A.12.b

  • Code Also — related condition(2 notes)

    Coding workflow: Review the related condition when both are documented and the instruction applies. A Code Also note does not fix sequencing; the order follows the circumstances of the encounter.

    ReviewZ51.81

    See the official tabular notes · Guidelines I.A.17

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Don’t confuse Z79.4 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of Z79.4 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

  • Z79.85— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of long-term (current) use of injectable non-insulin antidiabetic drugs adds Z79.85; it is not part of this code and both may be reported when both are documented.

    Full comparison: Z79.4 vs Z79.85 →

  • Z79.84— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of long term (current) use of oral antidiabetic drugs adds Z79.84; it is not part of this code and both may be reported when both are documented.

    Full comparison: Z79.4 vs Z79.84 →

  • F11— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of drug abuse and dependence adds F11; it is not part of this code and both may be reported when both are documented.

    Full comparison: Z79.4 vs F11 →

  • F19— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of drug abuse and dependence adds F19; it is not part of this code and both may be reported when both are documented.

    Full comparison: Z79.4 vs F19 →

  • O99.32— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of drug use complicating pregnancy, childbirth, and the puerperium adds O99.32; it is not part of this code and both may be reported when both are documented.

    Full comparison: Z79.4 vs O99.32 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Coding context

Guidelines, coding notes, decision aids, relationships (with MS-DRG and CCSR classification), hierarchy, HCC, coverage and the context map: what a coder reaches for after the core. Each section names whether it is official source data, a MedCoder-derived relationship or MedCoder editorial.

Code Overview

Long term (current) use of insulin is a billable ICD-10-CM diagnosis code (Z79.4).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Official Coding Guidelines

Official source data — quoted verbatim from the CMS/NCHS Official Guidelines

Verbatim excerpts from the ICD-10-CM Official Guidelines for Coding and Reporting (CMS/NCHS) that govern this code.

Chapter 4: Endocrine, Nutritional, and Metabolic Diseases (E00 -E89)

3) Diabetes mellitus and the use of insulin, oral hypoglycemics, and injectable non-insulin drugs If the documentation in a medical record does not indicate the type of diabetes but does indicate that the patient uses insulin, code E11-, Type 2 diabetes mellitus, should be assigned. Additional code(s) should be assigned from category Z79 to identify the long-term (current) use of insulin, oral hypoglycemic drugs, or injectable non-insulin antidiabetic, as follows: If the patient is treated with both oral hypoglycemic drugs and insulin, both code Z79.4, Long term (current) use of insulin, and code Z79.84, Long term (current) use of oral hypoglycemic drugs, should be assigned. If the patient is treated with both insulin and an injectable non-insulin antidiabetic drug, assign codes Z79.4, Long term (current) use of insulin, and Z79.85, Long-term (current) use of injectable non-insulin antidiabetic drugs. If the patient is treated with both oral hypoglycemic drugs and an injectable non-insulin antidiabetic drug, assign codes Z79.84, Long term (current) use of oral hypoglycemic drugs, and Z79.85, Long-term (current) use of injectable non-insulin antidiabetic drugs. Code Z79.4 should not be assigned if insulin is given temporarily to bring a type 2 patient’s blood sugar under control during an encounter.

Chapter 4: Endocrine, Nutritional, and Metabolic Diseases (E00 -E89)

(a) Secondary diabetes mellitus and the use of insulin, oral hypoglycemic drugs, or injectable non-insulin drugs For patients with secondary diabetes mellitus who routinely use insulin, oral hypoglycemic drugs, or injectable non-insulin drugs, additional code(s) from category Z79 should be assigned to identify the long-term (current) use of insulin, oral hypoglycemic drugs, or non-injectable non-insulin drugs as follows: If the patient is treated with both oral hypoglycemic drugs and insulin, both code Z79.4, Long term (current) use of insulin, and code Z79.84, Long term (current) use of oral hypoglycemic drugs, should be assigned. If the patient is treated with both insulin and an injectable non- insulin antidiabetic drug, assign codes Z79.4, Long- term (current) use of insulin, and Z79.85, Long-term (current) use of injectable non-insulin antidiabetic drugs. If the patient is treated with both oral hypoglycemic drugs and an injectable non-insulin antidiabetic drug, assign codes Z79.84, Long-term (current) use of oral hypoglycemic drugs, and Z79.85, Long-term (current) use of injectable non-insulin antidiabetic drugs. Code Z79.4 should not be assigned if insulin is given temporarily to bring a secondary diabetic patient’s blood sugar under control during an encounter.

Chapter 15: Pregnancy, Childbirth, and the Puerperium (O00-O9A)

The codes under subcategory O24.4 include diet controlled, insulin controlled, and controlled by oral hypoglycemic drugs. If a patient with gestational diabetes is treated with both diet and insulin, only the code for insulin-controlled is required. If a patient with gestational diabetes is treated with both diet and oral hypoglycemic medications, only the code for "controlled by oral hypoglycemic drugs" is required. Codes Z79.4, Long-term (current) use of insulin, Z79.84, Long-term (current) use of oral hypoglycemic drugs, and Z79.85, Long-term (current) use of injectable non-insulin antidiabetic drugs, should not be assigned with codes from subcategory O24.4.

Chapter 21: Factors influencing health status and contact with health services (Z00-Z99)

Z74.01 Bed confinement status Z76.82 Awaiting organ transplant status Z78 Other specified health status Code Z78.1, Physical restraint status, may be used when it is documented by the provider that a patient has been put in restraints during the current encounter. Please note that this code should not be reported when it is documented by the provider that a patient is temporarily restrained during a procedure. Z79 Long- term (current) drug therapy Codes from this category indicate a patient’s continuous use of a prescribed drug (including such things as aspirin therapy) for the long-term treatment of a condition or for prophylactic use. It is not for use for patients who have addictions to drugs. This subcategory is not for use of medications for detoxification or maintenance programs to prevent withdrawal symptoms (e.g., methadone maintenance for opiate dependence). Assign the appropriate code for the drug use, abuse, or dependence instead.

Chapter 21: Factors influencing health status and contact with health services (Z00-Z99)

Assign a code from Z79 if the patient is receiving a medication for an extended period as a prophylactic measure (such as for the prevention of deep vein thrombosis) or as treatment of a chronic condition (such as arthritis) or a disease requiring a lengthy course of treatment (such as cancer). Do not assign a code from category Z79 for medication being administered for a brief period of time to

Verify Before Coding

  • No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder-derived relationships — computed from published CMS and AHRQ datasets

Other codes that name Z79.4 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 3 Excludes2 notes: Z79.84 — Long term (current) use of oral hypoglycemic drugs, Z79.85 — Long-term (current) use of injectable non-insulin antidiabetic drugs, Z92.2 — Personal history of drug therapy (via Z79.-).

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

Referenced by 10 Use Additional Code instructions across 3 chapters: E08 — Diabetes mellitus due to underlying condition, E09 — Drug or chemical induced diabetes mellitus, E11 — Type 2 diabetes mellitus, E13 — Other specified diabetes mellitus, E89.1 — Postprocedural hypoinsulinemia, O24.1 — Pre-existing type 2 diabetes mellitus, in pregnancy, childbirth and the puerperium, O24.3 — Unspecified pre-existing diabetes mellitus in pregnancy, childbirth and the puerperium, O24.8 — Other pre-existing diabetes mellitus in pregnancy, childbirth, and the puerperium, O24.9 — Unspecified diabetes mellitus in pregnancy, childbirth and the puerperium, Z90.41 — Acquired absence of pancreas.

These codes instruct coders to additionally report this code when it applies.

Referenced by 1 Code Also instruction: Z51.81 — Encounter for therapeutic drug level monitoring (via Z79.-).

These codes suggest coding this condition alongside when both are present.

MS-DRG Grouper Relationships (FY2027)

Potential MS-DRG participation — not a DRG assignment.

FY2027 MS-DRG: not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity for that release.

Named in the grouper logic of 2 MS-DRGs: DRG 949 (MDC 23), DRG 950 (MDC 23).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):FAC025 — Other specified status (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same CMS-HCC risk category (V28)

CMS maps these diagnoses to the same Hierarchical Condition Category (Diabetes with Glycemic, Unspecified, or No Complications) for risk-adjusted payment.

E08.649 — Diabetes mellitus due to underlying condition with hypoglycemia without coma, E08.65 — Diabetes mellitus due to underlying condition with hyperglycemia, E08.8 — Diabetes mellitus due to underlying condition with unspecified complications, E08.9 — Diabetes mellitus due to underlying condition without complications, E10.649 — Type 1 diabetes mellitus with hypoglycemia without coma, E10.65 — Type 1 diabetes mellitus with hyperglycemia, E10.8 — Type 1 diabetes mellitus with unspecified complications, E10.9 — Type 1 diabetes mellitus without complications, E11.649 — Type 2 diabetes mellitus with hypoglycemia without coma, E11.65 — Type 2 diabetes mellitus with hyperglycemia, E11.8 — Type 2 diabetes mellitus with unspecified complications, E11.9 — Type 2 diabetes mellitus without complications, E13.649 — Other specified diabetes mellitus with hypoglycemia without coma, E13.65 — Other specified diabetes mellitus with hyperglycemia, E13.8 — Other specified diabetes mellitus with unspecified complications, E13.9 — Other specified diabetes mellitus without complications

Related risk categories

These categories interact through CMS's HCC hierarchy — one can suppress the other's risk-adjustment weight when both are present on a claim.

Pancreas Transplant Status, Diabetes with Severe Acute Complications, Diabetes with Chronic Complications

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Other specified status).

Z77.39 — Contact with and (suspected) exposure to other war theater, Z77.9 — Other contact with and (suspected) exposures hazardous to health, Z78.0 — Asymptomatic menopausal state, Z78.1 — Physical restraint status, Z78.9 — Other specified health status, Z79.01 — Long term (current) use of anticoagulants, Z79.02 — Long term (current) use of antithrombotics/antiplatelets, Z79.1 — Long term (current) use of non-steroidal anti-inflammatories (NSAID), Z79.2 — Long term (current) use of antibiotics, Z79.3 — Long term (current) use of hormonal contraceptives, Z79.51 — Long term (current) use of inhaled steroids, Z79.52 — Long term (current) use of systemic steroids, Z79.60 — Long term (current) use of unspecified immunomodulators and immunosuppressants, Z79.61 — Long term (current) use of immunomodulator, Z79.620 — Long term (current) use of immunosuppressive biologic, Z79.621 — Long term (current) use of calcineurin inhibitor, Z79.622 — Long term (current) use of Janus kinase inhibitor, Z79.623 — Long term (current) use of mammalian target of rapamycin (mTOR) inhibitor, Z79.624 — Long term (current) use of inhibitors of nucleotide synthesis, Z79.630 — Long term (current) use of alkylating agent, +232 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Therapy”; these codes share that main term but sit in a different category of the Tabular List.

F11.20 — Opioid dependence, uncomplicated

Lab tests where this diagnosis supports Medicare coverage (NCD)

Medicare's National Coverage Determination (NCD) program lists this diagnosis as medical justification for these lab tests.

HbA1c Test (Glycated Hemoglobin), Blood Glucose Test

Contextual Map

Every relationship of Z79.4 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run Z79.4 with these 12 related codes in Claim Check

Hierarchy

Excludes2

Referenced by Excludes2 notes

Referenced by Use Additional Code instructions (10)

Referenced by Code Also instructions

Clinical classification (CCSR)

Risk adjustment (CMS-HCC)

  • HCC 38 — Diabetes with Glycemic, Unspecified, or No Complications [CMS-HCC]— CMS-HCC V28 · 2026

MS-DRG Grouper

MDC crossing

  • MDC 23 — Factors Influencing Health Status and Other Contacts with Health Services[MDC crossing]: “Factors Influencing Health Status and Other Contacts with Health Services — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 1,258 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2027

Index entries

  • Long-term (current) (prophylactic) drug therapy (use of), insulin[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Therapy, drug, long-term (current) (prophylactic), insulin[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027

Nearest codes (40)

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Reference

Index terms and tables, published questions and FAQ, every source behind this page with its release and checksum, the date-of-service check and the complete change history.

Indexed Clinical Terms (2)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2027 tabular list, index and tables, effective October 1, 2026 Release, file and checksum · Publisher’s page
Coding guidelines Official source data
ICD-10-CM Official Guidelines for Coding and Reporting (FY2027), quoted by section Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v44.0 (October 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v44 Release, file and checksum · Publisher’s page
Risk adjustment Official source data
2026 Mid-Year Final ICD-10 Mappings + Model Software (cms.gov/files/zip/2026-midyear-final-icd-10-mappings.zip, 2026-midyear-final-model-software.zip) — CMS-HCC V28, PY2026 mid-year final release Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder-derived relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder editorial explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Current data releases:ICD-10-CM FY2027 · ICD-10-PCS FY2027 · HCPCS October 2026 · MS-DRG v44 · Medicare Code Editor v44.0 · NCCI PTP Q4 2026 · MUE Q4 2026 · NCD code lists 2026-01 · LCD export September 28, 2026 · All releases and sources

Labels on this page: Official source data · MedCoder-derived relationship · MedCoder editorial explanation. How to read the labels · All data sources and release dates · CMS coding rules

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "Z79.4 — Long term (current) use of insulin." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/z79.4-long-term-current-use-of-insulin

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Long term (current) use of insulin

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027, and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to Z79.4 in its code family, with their registry titles.

View all codes in the Z79 family