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H35.0 vs I10

H35.0 (Background retinopathy and retinal vascular changes) compared with I10 (Essential (primary) hypertension), from the official CMS tabular data.

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

Summary

These codes can be reported together when both conditions are documented, because I10 lists H35.0 under Excludes2, which marks them as distinct conditions.

Official rule
What is different?

The conditions named, billing status and chapter.H35.0 is “Background retinopathy and retinal vascular changes”; I10 is “Essential (primary) hypertension”. H35.0 is a non-billable header; I10 is billable. H35.0 sits in H00-H59 — Diseases of the Eye and Adnexa (H00-H59); I10 in I00-I99 — Diseases of the Circulatory System (I00-I99).

Registry fact

Can these codes be reported together?

Yes, when both are documented.I10 lists H35.0 under Excludes2: “essential (primary) hypertension involving vessels of eye (H35.0-)”. Excludes2 marks distinct conditions that may both be reported when both are documented.

Official ruleGuide: Excludes1 vs Excludes2

Is there an Excludes2 relationship?

Yes.I10’s tabular entry: “essential (primary) hypertension involving vessels of eye (H35.0-)”. The note covers H35.0.

Official ruleGuide: Excludes1 vs Excludes2

Is one a parent or header code?

One is a header.H35.0 is a non-billable header, but I10 is not one of its subdivisions.

Registry fact

Are there sequencing instructions?

No order is given.The Code Also note linking them states no sequencing order; sequence by the reason for the encounter.

Official ruleGuide: Code First vs Use Additional Code vs Code Also

Are there other coding relationships?

Yes.Both codes may be needed together. H35.0 carries a Code Also note covering I10: “any associated hypertension (I10)”

Official ruleGuide: Code First vs Use Additional Code vs Code Also

Nothing found in 1 other check; 1 check does not apply
Is there an Excludes1 relationship?

None.Neither entry carries an Excludes1 note that names the other code. I10 carries 3 Excludes1 notes covering other codes; the side-by-side table quotes them.

Official rule

Is one more specific?

Not comparable.The codes sit in different categories; specificity is only comparable within one category.

Official rule: a tabular instructional note or a section of the ICD-10-CM Official Guidelines, quoted as published. Registry fact: the codes’ own published attributes (titles, billable status, position in the hierarchy, code set). MedCoder-derived: a reading MedCoder computes from those facts; it is not itself a rule. How to read the labels

Can these codes be reported together?

Informational

Code Also relationship

H35.0
Background retinopathy and retinal vascular changes
↔
I10
Essential (primary) hypertension

What we found

Both codes may be needed together.H35.0 carries a Code Also note covering I10: “any associated hypertension (I10)”

A Code Also note means the two codes may both be required to fully describe the condition. CMS states no sequencing order for it — sequence by the reason for the encounter.

What to review

Report both when both are needed to describe the condition, sequenced by the reason for the encounter.

Guide: Code First vs Use Additional Code vs Code AlsoCheck these on a claim

Why it matters

A "Code Also" note means two codes may be required together, but the Guidelines state no sequencing order for it -- sequence by the reason for the encounter, not by this relationship.

Source / rule

CMS ICD-10-CM tabular instructional notes

Informational

Excludes2 relationship

I10
Essential (primary) hypertension
↔
H35.0
Background retinopathy and retinal vascular changes

What we found

Yes, when both are documented.I10 carries an Excludes2 note covering H35.0: “essential (primary) hypertension involving vessels of eye (H35.0-)”

Excludes2 marks distinct conditions — both may be reported when both are documented.

What to review

Report both only when the documentation supports both conditions; otherwise report the one documented.

Guide: Excludes1 vs Excludes2Check these on a claim

Why it matters

An Excludes2 note means the excluded condition is not part of the code above it, but a patient can have both. Report both when both are documented.

Source / rule

CMS ICD-10-CM tabular instructional notes

Official guidance behind these answers

  • Section I.A.12.b — Excludes2 · applies to: Excludes2

    A type 2 Excludes note represents “Not included here.” An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.

    ICD-10-CM Official Guidelines FY2027

  • Section I.A.17 — “Code also ” note · applies to: Code also

    A “code also” note instructs that two codes may be required to fully describe a condition, but this note does not provide sequencing direction. The sequencing depends on the circumstances of the encounter.

    ICD-10-CM Official Guidelines FY2027

Quoted from the ICD-10-CM Official Guidelines for Coding and Reporting in effect for the release shown. The tabular notes above are the code-level instruction; these sections are the convention that says how such a note is applied. Source document (CMS PDF) · Release and checksum

Side by side

Similar descriptions do not make codes interchangeable. The documentation and the official instructions decide which code applies.

Official descriptionDiffers
H35.0

Background retinopathy and retinal vascular changes

I10

Essential (primary) hypertension

StatusDiffers
H35.0
Non-billable header

A header is not reported on a claim; a code beneath it is.

Report instead: H35.00, H35.011, H35.012, H35.013, H35.019

I10
Billable
Excludes1Differs
H35.0

None at this code

I10
  • hypertensive disease complicating pregnancy, childbirth and the puerperium (O10-O11, O13-O16)
  • neonatal hypertension (P29.2)
  • primary pulmonary hypertension (I27.0)
Excludes2Differs
H35.0
  • diabetic retinal disorders (E08.311-E08.359, E09.311-E09.359, E10.311-E10.359, E11.311-E11.359, E13.311-E13.359)
I10
  • essential (primary) hypertension involving vessels of brain (I60-I69)
  • essential (primary) hypertension involving vessels of eye (H35.0-)
Use additional codeDiffers
H35.0

None at this code

I10
  • code to identify:
  • exposure to environmental tobacco smoke (Z77.22)
  • history of tobacco dependence (Z87.891)
  • occupational exposure to environmental tobacco smoke (Z57.31)
  • tobacco dependence (F17.-)
  • tobacco use (Z72.0)
Code alsoDiffers
H35.0
  • any associated hypertension (I10)
I10

None at this code

CategoryDiffers
H35.0

H35 Other retinal disorders

I10

Is itself a category

ChapterDiffers
H35.0

H00-H59 — Diseases of the Eye and Adnexa (H00-H59)

I10

I00-I99 — Diseases of the Circulatory System (I00-I99)

IncludesDiffers
H35.0

None at this code

I10
  • high blood pressure
  • hypertension (arterial) (benign) (essential) (malignant) (primary) (systemic)

No Code first and 7th character note at either code.

Notes are the code’s own tabular entry, quoted as published. A note that names the other code is the one the verdict above rests on. In a row that differs, each code’s own notes are listed under it, and the notes every code shares are listed once beneath them.

Edit this comparisonCheck a whole claim

Derived from the official CMS ICD-10-CM tabular data (FY2027). A coding-rule comparison, not billing advice: payer-specific edits and medical-necessity policy are outside its scope. All data sources