ICD-10 H20.00
Billable / Specific CCUnspecified acute and subacute iridocyclitis
About ICD-10-CM H20.00
ICD-10-CM code H20.00 represents Unspecified acute and subacute iridocyclitis. This is a billable/specific code in the Eye and Adnexa chapter (block H20). The 2026 edition of ICD-10-CM H20.00 became effective on October 1, 2025.
Coding Tips for H20.00
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
H20.00 is designated CC for MS-DRG grouping. On inpatient claims, this code can shift the DRG to the with-CC variant when documented as a present-on-admission secondary diagnosis. Hospital CDI programs flag CC opportunities during chart review. Failure to capture this code may leave 30 to 80 percent of the inpatient stay revenue unrealized.
Inpatient DRG Impact, CC
codes Unspecified acute and subacute iridocyclitis. As a Complication/Comorbidity (CC), this contributes to DRG severity adjustment when documented alongside the principal diagnosis.
Medicare LCD Coverage for H20.00
Local Coverage Determinations (LCDs) from CMS MACs that list H20.00 as a covered diagnosis.
Showing top 10 of 21 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing H20.00.
5 Medicare
1 Aetna
CPT Codes Commonly Billed with H20.00
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
Convert H20.00 to ICD-9-CM
Per CMS General Equivalence Mappings (GEMs), useful for legacy data review and historical claim analysis.
| ICD-10 | ICD-9 | Mapping Flags |
|---|---|---|
| H20.00 | 36400 | 00000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To H20.00
Other codes in section H15-H22 (Disorders of sclera, cornea, iris and ciliary body).
ICD-10 H20.00, Billing FAQ
Is ICD-10 code H20.00 billable? +
Yes, H20.00 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
Is H20.00 a CC or MCC for inpatient DRG? +
Yes, this code is designated as CC. Documenting as a secondary diagnosis on inpatient claims can shift the DRG to a higher-weighted category.
What CPT codes are commonly billed with H20.00? +
Procedures frequently paired with H20.00 include: J1745, Q5104, Q5121, Q5103.
What ICD-9 codes does H20.00 map to? +
Per CMS GEMs, H20.00 maps to ICD-9 codes: 36400. Useful for legacy data review and historical claim analysis.
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Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on June 1, 2026.
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