I10 ICD-10-CM Code: Essential (primary) hypertension

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for I10 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Notes without a marker are published on I10 itself; “inherited from” names the category or block whose note applies here.

Coder workflow for I10

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

Before you code I10

1. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with I10. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

   See the official tabular notes

Choose the right path

1. Does the documentation support a condition named in I10’s Excludes1 note?
   Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
   No → Continue.

   ReviewP29.2, I27.0

Consider I10. Then work the Use Additional Code note, and confirm the code is valid for the date of service in the Verify section.

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 conditions the Use Additional Code note names

Reported with this code when documented; a conditional instruction (“if applicable”, “if known”) applies only when the record supports it.

Heart involvement, chronic kidney disease and its stage, cause, crisis, pregnancy

Each moves the case to a different hypertension category (Guidelines I.C.9.a).

Official instructions as workflow

• Excludes1 — check before selecting I10(3 notes)

  Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with I10: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

  CompareP29.2, I27.0

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

• Excludes2 — not part of I10(2 notes)

  Coding workflow: The conditions named in this note are not included in I10. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

  CompareH35.0

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

• Use Additional Code — after identifying I10(6 notes)

  Coding workflow: Check whether the documentation supports the additional code(s) the note names, and report them with I10 when it does. Where the instruction is conditional (“if applicable”, “if known”), it applies only when the record documents the condition.

  ReviewZ77.22, Z87.891, Z57.31, F17, Z72.0

  See the official tabular notes · Guidelines I.A.13

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.

Before you code I10

MedCoder editorial — not official ICD-10-CM text; reviewed against the cited source

This checklist routes you to the categories to review — it does not determine the final code.

I10 reports a documented diagnosis of hypertension that the classification files as essential (primary) — including hypertension documented without further specification — when no heart involvement, chronic kidney disease, identified cause, crisis, or pregnancy context is documented. An elevated blood-pressure reading alone is not that diagnosis. Each documentation pattern below moves the case elsewhere — check for these before settling on I10.

• Elevated blood-pressure reading, with no documented diagnosis of hypertension → R03.0 Elevated blood-pressure reading

  Code assignment follows the provider’s diagnostic statement (Guidelines I.A.19); without an established hypertension diagnosis the reading is R03.0, not I10 (I.C.9.a.7).

• Heart condition in I50.- or I51.4-I51.7, I51.89, I51.9 documented → I11.- Hypertensive heart disease

  The classification presumes the causal link (Guidelines I.C.9.a.1); I11.0 also requires an additional I50.- code for the heart-failure type.

• Chronic kidney disease (N18.-) documented → I12.- Hypertensive chronic kidney disease

  The presumption covers kidney involvement too (I.C.9.a.2); the N18.- stage is reported as a secondary code and decides I12.0 versus I12.9.

• Both a qualifying heart condition and chronic kidney disease documented → I13.- Hypertensive heart and chronic kidney disease

  I13 includes any condition in I11.- with any condition in I12.- — one I13.- code is used, not an I11/I12 split (I.C.9.a.3).

• Hypertension documented as secondary to another condition → I15.- Secondary hypertension

  Secondary hypertension takes two codes — the underlying etiology and a code from I15.- — sequenced by the reason for the encounter (I.C.9.a.6).

• Hypertensive crisis, urgency, or emergency documented → I16.- Hypertensive crisis

  I16.- is added alongside the hypertension code, not instead of it — category I16 says to code also any identified hypertensive disease (I.C.9.a.10).

• Resistant hypertension documented → I1A.0 Resistant hypertension

  I1A.0 is an additional code; the specific type of existing hypertension, such as I10, is sequenced first when known (I.C.9.a.12).

• Hypertension in pregnancy, childbirth, or the puerperium → O10-O16 Hypertensive disorders in pregnancy

  I10 carries an Excludes1 for hypertensive disease complicating pregnancy — the chapter 15 categories classify it instead.

• Provider documents the heart or kidney condition as unrelated to the hypertension → the "with" convention

  A clear unrelated statement is the one thing that defeats the presumption — the conditions are then coded separately (I10 or I15.- plus the condition), sequenced by the circumstances of the encounter (I.A.15, I.C.9.a.1).

ICD-10-CM presumes hypertension is related to documented heart involvement and chronic kidney disease even without causal wording; review the Official Guidelines before treating them as unrelated. The "With" Convention: When ICD-10-CM Presumes Two Conditions Are Related →

Provider documentation and the ICD-10-CM Official Guidelines control; verify against the official tabular notes on this page.

Indexed Clinical Terms (1)

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.

• Hypertension, hypertensive (accelerated) (benign) (essential) (idiopathic) (malignant) (systemic)

Official Coding Guidelines

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

Coding Notes

MedCoder editorial — not official ICD-10-CM text; reviewed against the cited source

What this code means

I10 is the default code for hypertension documented without a stated cause and without the heart or kidney involvement the classification links to it. Its own Includes note sweeps in nearly every descriptor — benign, malignant, essential, systemic — so severity wording alone does not move a case off I10. What moves it is documented company: ICD-10-CM links hypertension to heart involvement (I11.-), chronic kidney disease (I12.-), or both (I13.-) through the "with" convention, presumes those relationships even when no causal wording appears, and reserves I15.- for hypertension with a documented cause. I16.- (crisis) and I1A.0 (resistant) work differently — they are reported alongside the hypertension code rather than replacing it.

Coding guidance

• The presumption is documentation-driven: hypertension plus a qualifying heart condition or CKD is coded as related unless the provider clearly states they are unrelated (Guidelines I.A.15, I.C.9.a).
• The combination categories carry additional-code duties: I11.0 needs the I50.- heart-failure type, I12.- and I13.- need the N18.- stage as a secondary code, and I13.0/I13.2 need both.
• Hypertension involving vessels of brain or eye stays outside these combinations: assign the I60-I69 code first for hypertensive cerebrovascular disease, and pair H35.0- with the hypertension code for hypertensive retinopathy (I.C.9.a.4-5).
• "Controlled" and "uncontrolled" are statements about therapy, not separate codes — both take the appropriate code from the hypertensive-disease categories (I.C.9.a.8-9). Documented resistant hypertension is different: it has its own code, I1A.0, added alongside the hypertension code (I.C.9.a.12) — an "uncontrolled" statement alone does not make it resistant.
• An elevated blood-pressure reading without an established hypertension diagnosis is R03.0, not I10 (I.C.9.a.7) — code assignment follows the provider’s diagnostic statement, not the reading or the clinical criteria behind it (I.A.19).

Decision-rule scenarios

Scenarios state the decision rule, not a code assignment — code selection always follows the provider's documentation and the ICD-10-CM Official Guidelines.

Documentation checklist

• The hypertension statement itself — essential, primary, NOS, or a descriptor from I10’s Includes note.
• Any heart condition in I50.- or I51.4-I51.7, I51.89, I51.9, and whether the provider ties it to, or explicitly separates it from, the hypertension.
• Any chronic kidney disease statement and its N18.- stage.
• Any documented cause (renal, endocrine, medication-related) that would make the hypertension secondary.
• Crisis, urgency, emergency, or resistant wording, which adds I16.- or I1A.0 alongside the hypertension code.
• Pregnancy status — hypertensive disease complicating pregnancy leaves I10 entirely.

Codes are assigned from provider documentation; a coder never infers a diagnosis.

Common mistakes

• Keeping I10 on the claim next to an I11.-, I12.-, or I13.- combination code — the combination already contains the hypertension.
• Reporting I11.- plus I12.- when heart and kidney involvement coexist; I13.- includes both together.
• Dropping the N18.- stage code under I12.-/I13.-, or the I50.- type under I11.0 — the Use Additional Code notes require them.
• Treating documented hypertensive urgency or emergency as plain I10 — category I16 claims the crisis, coded alongside the hypertensive disease.
• Coding I10 from an elevated blood-pressure reading alone; without an established diagnosis that is R03.0 — and a medication list alone is not a diagnostic statement either.
• Treating documented resistant hypertension as merely "uncontrolled" — uncontrolled takes the ordinary hypertension code alone (I.C.9.a.9), while documented resistant hypertension adds I1A.0 (I.C.9.a.12). The reverse error, adding I1A.0 without provider documentation of resistance, is equally wrong.
• Assuming "malignant" or "benign" changes the code — I10’s Includes note covers those descriptors; only documented crisis wording adds I16.-.

Written and reviewed by MedCoder against the official ICD-10-CM files; educational, not medical or billing advice. The official tabular notes and guidelines above take precedence in every case.

Don’t confuse I10 with…

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

The codes most likely to be picked instead of I10 — 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.

• R03.0— Documentation boundary (Review)

  I10 asserts a diagnosis — the provider has documented essential (primary) hypertension. R03.0 asserts only a finding: an elevated blood-pressure reading in a patient with no diagnosis of hypertension. A number on the chart, however high, never converts to I10 by itself; the provider’s diagnostic statement is what moves the record across that line.

  Deciding question: Has the provider documented a diagnosis of hypertension, or only an elevated reading?

  Full comparison: I10 vs R03.0 →

• O10— Excludes1 conflict (Excludes1 — generally not reported together)

  Pregnancy changes the chapter: pre-existing hypertension complicating pregnancy, childbirth, or the puerperium is reported with O10.-, not I10.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of hypertensive disease complicating pregnancy, childbirth and the puerperium moves the case to O10; the two are not reported together unless documented as unrelated.

  Full comparison: I10 vs O10 →

• O11— Excludes1 conflict (Excludes1 — generally not reported together)

  Pre-existing hypertension with superimposed pre-eclampsia during pregnancy is O11.-, not I10.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of hypertensive disease complicating pregnancy, childbirth and the puerperium moves the case to O11; the two are not reported together unless documented as unrelated.

  Full comparison: I10 vs O11 →

• O13— Excludes1 conflict (Excludes1 — generally not reported together)

  Gestational (pregnancy-induced) hypertension without significant proteinuria is O13.-, not I10.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of hypertensive disease complicating pregnancy, childbirth and the puerperium moves the case to O13; the two are not reported together unless documented as unrelated.

  Full comparison: I10 vs O13 →

• O16— Excludes1 conflict (Excludes1 — generally not reported together)

  Unspecified maternal hypertension during pregnancy is O16.-, not I10.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of hypertensive disease complicating pregnancy, childbirth and the puerperium moves the case to O16; the two are not reported together unless documented as unrelated.

  Full comparison: I10 vs O16 →

• P29.2— Excludes1 conflict (Excludes1 — generally not reported together)

  Hypertension in a newborn is neonatal hypertension (P29.2); I10 is written for the adult systemic disease.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of neonatal hypertension moves the case to P29.2; the two are not reported together unless documented as unrelated.

  Full comparison: I10 vs P29.2 →

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.

Decision Points

The directives on this code's own record, as a pre-claim checklist.

1. 6 Use Additional Code instructions — report the named additional code(s) when the documentation supports them. See the Use Additional Code notes
2. 3 Excludes1 entries — codes named there are generally not reported together with this code (Guidelines I.A.12.a). See the Excludes1 notes
3. 2 Excludes2 entries — those conditions are not part of this code and may be reported additionally when documented. See the Excludes2 notes

Checklist rows are derived from this code's own official directives; the wording of each check is MedCoder editorial. The official notes themselves are in the sections each row links to.

Verify Before Coding

• Questionable admission. The Medicare Code Editor lists this among its questionable-admission codes: reported as the principal diagnosis, it is not usually sufficient justification for an inpatient admission on its own, so it flags the admission as questionable. The code itself remains acceptable as principal.

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 structured relationships — computed from published CMS and AHRQ datasets

Other codes that name I10 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 1 Code First instruction: I1A.0 — Resistant hypertension.

Each of these codes carries a Code First note naming this condition — when that code is reported, THIS code is sequenced first, ahead of it.

Referenced by 4 Code Also instructions across 2 chapters: H35.0 — Background retinopathy and retinal vascular changes, I16 — Hypertensive crisis, I67.4 — Hypertensive encephalopathy, I87.2 — Venous insufficiency (chronic) (peripheral).

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

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 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 304 (MDC 05), DRG 305 (MDC 05).

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

Clinical classification (AHRQ CCSR):CIR007 — Essential hypertension (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 clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Essential hypertension).

O10.011 — Pre-existing essential hypertension complicating pregnancy, first trimester, O10.012 — Pre-existing essential hypertension complicating pregnancy, second trimester, O10.013 — Pre-existing essential hypertension complicating pregnancy, third trimester, O10.019 — Pre-existing essential hypertension complicating pregnancy, unspecified trimester, O10.02 — Pre-existing essential hypertension complicating childbirth, O10.03 — Pre-existing essential hypertension complicating the puerperium, O10.911 — Unspecified pre-existing hypertension complicating pregnancy, first trimester, O10.912 — Unspecified pre-existing hypertension complicating pregnancy, second trimester, O10.913 — Unspecified pre-existing hypertension complicating pregnancy, third trimester, O10.919 — Unspecified pre-existing hypertension complicating pregnancy, unspecified trimester, O10.92 — Unspecified pre-existing hypertension complicating childbirth, O10.93 — Unspecified pre-existing hypertension complicating the puerperium, O16.1 — Unspecified maternal hypertension, first trimester, O16.2 — Unspecified maternal hypertension, second trimester, O16.3 — Unspecified maternal hypertension, third trimester, O16.4 — Unspecified maternal hypertension, complicating childbirth, O16.5 — Unspecified maternal hypertension, complicating the puerperium, O16.9 — Unspecified maternal hypertension, unspecified trimester

Same Index main term, other category

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

B65.9 — Schistosomiasis, unspecified (portal, in), F45.8 — Other somatoform disorders (psychogenic), G93.2 — Benign intracranial hypertension (benign, intracranial), H40.05 — Ocular hypertension (ocular), I11.0 — Hypertensive heart disease with heart failure (with, heart failure), I11.9 — Hypertensive heart disease without heart failure (heart), I12.0 — Hypertensive chronic kidney disease with stage 5 chronic kidney disease or end stage renal disease (kidney, with, stage 5 chronic kidney disease), I12.9 — Hypertensive chronic kidney disease with stage 1 through stage 4 chronic kidney disease, or unspecified chronic kidney disease (kidney), I13.0 — Hypertensive heart and chronic kidney disease with heart failure and stage 1 through stage 4 chronic kidney disease, or unspecified chronic kidney disease (cardiorenal, with heart failure), I13.10 — Hypertensive heart and chronic kidney disease without heart failure, with stage 1 through stage 4 chronic kidney disease, or unspecified chronic kidney disease (cardiorenal), I13.11 — Hypertensive heart and chronic kidney disease without heart failure, with stage 5 chronic kidney disease, or end stage renal disease (cardiorenal, without heart failure, with stage 5 or end stage renal disease), I13.2 — Hypertensive heart and chronic kidney disease with heart failure and with stage 5 chronic kidney disease, or end stage renal disease (cardiorenal, with heart failure, with stage 5 or end stage renal disease), I15.0 — Renovascular hypertension (renovascular), I15.1 — Hypertension secondary to other renal disorders (due to, renal disorders NEC), I15.2 — Hypertension secondary to endocrine disorders (due to, pheochromocytoma), I15.8 — Other secondary hypertension (secondary NEC, specified NEC), I15.9 — Secondary hypertension, unspecified (secondary NEC), I16.0 — Hypertensive urgency (urgency), I16.1 — Hypertensive emergency (emergency), I16.9 — Hypertensive crisis, unspecified (crisis), +54 more

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.

Lipid Panel, Thyroid Stimulating Hormone (TSH)

Contextual Map

Every relationship of I10 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 I10 with these 24 related codes in Claim Check

Hierarchy

• I00-I99 — Chapter 9: Diseases of the Circulatory System (I00-I99) (I00-I99)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• I10-I1A — Hypertensive diseases[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Excludes1

• I27.0 — Primary pulmonary hypertension[Excludes1]: “primary pulmonary hypertension (I27.0)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• O10 — Pre-existing hypertension complicating pregnancy, childbirth and the puerperium[Excludes1]: “hypertensive disease complicating pregnancy, childbirth and the puerperium (O10-O11, O13-O16)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• O11 — Pre-existing hypertension with pre-eclampsia[Excludes1]: “hypertensive disease complicating pregnancy, childbirth and the puerperium (O10-O11, O13-O16)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• O13 — Gestational [pregnancy-induced] hypertension without significant proteinuria[Excludes1]: “hypertensive disease complicating pregnancy, childbirth and the puerperium (O10-O11, O13-O16)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• O14 — Pre-eclampsia[Excludes1]: “hypertensive disease complicating pregnancy, childbirth and the puerperium (O10-O11, O13-O16)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• O15 — Eclampsia[Excludes1]: “hypertensive disease complicating pregnancy, childbirth and the puerperium (O10-O11, O13-O16)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• O16 — Unspecified maternal hypertension[Excludes1]: “hypertensive disease complicating pregnancy, childbirth and the puerperium (O10-O11, O13-O16)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• P29.2 — Neonatal hypertension[Excludes1]: “neonatal hypertension (P29.2)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Excludes2 (10)

• H35.0 — Background retinopathy and retinal vascular changes[Excludes2]: “essential (primary) hypertension involving vessels of eye (H35.0-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• I60 — Nontraumatic subarachnoid hemorrhage[Excludes2]: “essential (primary) hypertension involving vessels of brain (I60-I69)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• I61 — Nontraumatic intracerebral hemorrhage[Excludes2]: “essential (primary) hypertension involving vessels of brain (I60-I69)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• I62 — Other and unspecified nontraumatic intracranial hemorrhage[Excludes2]: “essential (primary) hypertension involving vessels of brain (I60-I69)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• I63 — Cerebral infarction[Excludes2]: “essential (primary) hypertension involving vessels of brain (I60-I69)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• I65 — Occlusion and stenosis of precerebral arteries, not resulting in cerebral infarction[Excludes2]: “essential (primary) hypertension involving vessels of brain (I60-I69)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• I66 — Occlusion and stenosis of cerebral arteries, not resulting in cerebral infarction[Excludes2]: “essential (primary) hypertension involving vessels of brain (I60-I69)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• I67 — Other cerebrovascular diseases[Excludes2]: “essential (primary) hypertension involving vessels of brain (I60-I69)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• and 2 more

Use Additional Code

• F17 — Nicotine dependence[Use Additional Code]: “tobacco dependence (F17.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• Z57.31 — Occupational exposure to environmental tobacco smoke[Use Additional Code]: “occupational exposure to environmental tobacco smoke (Z57.31)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• Z72.0 — Tobacco use[Use Additional Code]: “tobacco use (Z72.0)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• Z77.22 — Contact with and (suspected) exposure to environmental tobacco smoke (acute) (chronic)[Use Additional Code]: “exposure to environmental tobacco smoke (Z77.22)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• Z87.891 — Personal history of nicotine dependence[Use Additional Code]: “history of tobacco dependence (Z87.891)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Code First instructions

• I1A.0 — Resistant hypertension[Code First]: “essential hypertension (I10)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Code Also instructions

• H35.0 — Background retinopathy and retinal vascular changes[Code Also]: “any associated hypertension (I10)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• I16 — Hypertensive crisis[Code Also]: “any identified hypertensive disease (I10-I15, I1A)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• I67.4 — Hypertensive encephalopathy[Code Also]: “essential (primary) hypertension (I10)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• I87.2 — Venous insufficiency (chronic) (peripheral)[Code Also]: “essential (primary) hypertension (I10)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Clinical classification (CCSR)

• CIR007 — Essential hypertension[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)

MS-DRG Grouper

• DRG 304 — HYPERTENSION WITH MCC[MS-DRG]: “HYPERTENSION WITH MCC (MDC 05)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 305 — HYPERTENSION WITHOUT MCC[MS-DRG]: “HYPERTENSION WITHOUT MCC (MDC 05)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026

MDC crossing

• MDC 05 — Diseases and Disorders of the Circulatory System[MDC crossing]: “Diseases and Disorders of the Circulatory System — 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. 17,209 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

• Hypertension, hypertensive (accelerated) (benign) (essential) (idiopathic) (malignant) (systemic)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Change history

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

Relevant guides

• The “With” Convention: When ICD-10-CM Presumes Two Conditions Are Related →
• How Do I Code Hypertension With Chronic Kidney Disease? I12, I13, and the N18 Stage →

Real-World Coding Questions

Questions working coders have asked about this code, answered from official sources and reviewed by an editor.

• When hypertension and chronic kidney disease are both documented, is that I10 with an N18 code, or a code from I12? →
• When do two individually valid codes conflict? →

Common coding questions

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 FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page

Coding guidelines Official source data

ICD-10-CM Official Guidelines for Coding and Reporting (FY2026), quoted by section Release, file and checksum · Publisher’s page

Claim edits Official source data

CMS Definitions of Medicare Code Edits — v43.1 (April 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 — v43 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 structured relationship

Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears

Summary, coding notes, decision checklist and FAQ answers MedCoder 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.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates