H10.529 ICD-10-CM Code: Angular blepharoconjunctivitis, unspecified eye

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for H10.529 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 H10.529 itself; “inherited from” names the category or block whose note applies here.

Coder workflow for H10.529

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

Before you code H10.529

1. Unspecified does not mean incorrect. When the record gives no greater specificity, H10.529 may be the appropriate code. Check the record for detail that supports a more specific sibling. An unspecified code is for records that do not provide the detail a more specific code needs; a query, not an assumption, is the route to specificity (Guidelines I.A.9.b, I.B.18).

   ReviewH10.521, H10.522, H10.523

   See the relationships section · Guide: Other vs unspecified (NEC vs NOS) →

2. Laterality is coded in this family. Confirm the side documented — right, left, or bilateral — and select the matching code (this page’s code: unspecified). The unspecified-side code applies only when the record states no side. Laterality is assigned from the documented side; where a bilateral code exists and both sides are documented, it is used instead of two unilateral codes (Guidelines I.B.13).

   ReviewH10.521 · right, H10.522 · left

   Guide: Laterality coding →

3. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with H10.529. 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 record document the detail a more specific sibling code needs?
   Yes → Review the specific siblings in this subcategory.
   No → Continue — H10.529 is appropriate when the documentation goes no further.

   ReviewH10.521, H10.522, H10.523

2. Does the documentation support a condition named in H10.529’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.

   ReviewH16.2

3. Is the side documented?
   Yes → Select the code for the documented side (or the bilateral code when both sides are documented and one exists).
   No → Use the unspecified-side code only when the record states no side; a query is the alternative.

   ReviewH10.521 · right, H10.522 · left

Consider H10.529. Then 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).

Laterality

Right, left or bilateral as documented; unspecified only when the record states no side (Guidelines I.B.13).

Any detail beyond this code’s title

What the record states that a more specific sibling code would capture — or its absence, which itself supports the unspecified code.

Official instructions as workflow

• Excludes1 — check before selecting H10.529(1 note)

  Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with H10.529: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

  CompareH16.2

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

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

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 H10.529 with…

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

The codes most likely to be picked instead of H10.529 — 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.

• H16.2— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

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

  What moves you there: Documentation of keratoconjunctivitis moves the case to H16.2; the two are not reported together unless documented as unrelated.

  Full comparison: H10.529 vs H16.2 →

• H10.521— Laterality relationship (Review)

  Same condition; these differ only in which side is documented.

  The same condition on the other side; the documented side decides, and a bilateral code, where one exists, replaces the pair when both sides are documented.

  What moves you there: A documented right side moves the case to H10.521.

  Full comparison: H10.529 vs H10.521 →

• H10.522— Laterality relationship (Review)

  Same condition; these differ only in which side is documented.

  The same condition on the other side; the documented side decides, and a bilateral code, where one exists, replaces the pair when both sides are documented.

  What moves you there: A documented left side moves the case to H10.522.

  Full comparison: H10.529 vs H10.522 →

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.

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 structured relationships — computed from published CMS and AHRQ datasets

Other codes that name H10.529 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 Excludes1 note: H01.0 — Blepharitis (via H10.5.-).

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

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 124 (MDC 02), DRG 125 (MDC 02).

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

Clinical classification (AHRQ CCSR):EYE001 — Cornea and external disease (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 condition, opposite side

Same category and title, differing only in which side of the body is affected.

H10.521 — Angular blepharoconjunctivitis, right eye (right)Compare H10.529 vs H10.521 →, H10.522 — Angular blepharoconjunctivitis, left eye (left)Compare H10.529 vs H10.522 →

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Cornea and external disease).

+809 more

Contextual Map

Every relationship of H10.529 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 H10.529 with this related code in Claim Check

Hierarchy

• H00-H59 — Chapter 7: Diseases of the Eye and Adnexa (H00-H59) (H00-H59)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• H10-H11 — Disorders of conjunctiva[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Referenced by Excludes1 notes

• H01.0 — Blepharitis[Excludes1](via H10.5.-): “blepharoconjunctivitis (H10.5-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Clinical classification (CCSR)

• EYE001 — Cornea and external disease[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)

MS-DRG Grouper

• DRG 124 — OTHER DISORDERS OF THE EYE WITH MCC OR THROMBOLYTIC AGENT[MS-DRG]: “OTHER DISORDERS OF THE EYE WITH MCC OR THROMBOLYTIC AGENT (MDC 02)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 125 — OTHER DISORDERS OF THE EYE WITHOUT MCC[MS-DRG]: “OTHER DISORDERS OF THE EYE WITHOUT MCC (MDC 02)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026

MDC crossing

• MDC 02 — Diseases and Disorders of the Eye[MDC crossing]: “Diseases and Disorders of the Eye — 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. 1,200 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Nearest codes (40)

• H10 — Conjunctivitis[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• H10.43 — Chronic follicular conjunctivitis[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• H10.431 — Chronic follicular conjunctivitis, right eye[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• H10.432 — Chronic follicular conjunctivitis, left eye[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• H10.433 — Chronic follicular conjunctivitis, bilateral[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• H10.439 — Chronic follicular conjunctivitis, unspecified eye[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• H10.44 — Vernal conjunctivitis[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• H10.45 — Other chronic allergic conjunctivitis[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• and 32 more

Change history

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

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

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 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

Nearest Codes in This Family

Official ICD-10-CM classifications closest to H10.529 in its code family, with their registry titles.

• H10.519 — Ligneous conjunctivitis, unspecified eye
• H10.52 — Angular blepharoconjunctivitis
• H10.521 — Angular blepharoconjunctivitis, right eye
• H10.522 — Angular blepharoconjunctivitis, left eye
• H10.523 — Angular blepharoconjunctivitis, bilateral
• H10.53 — Contact blepharoconjunctivitis
• H10.531 — Contact blepharoconjunctivitis, right eye
• H10.532 — Contact blepharoconjunctivitis, left eye
• H10.533 — Contact blepharoconjunctivitis, bilateral
• H10.539 — Contact blepharoconjunctivitis, unspecified eye

View all codes in the H10 family