Question 1

What is ICD-10 code H05.039?

Accepted Answer

H05.039 is the ICD-10-CM diagnosis code for periostitis of unspecified orbit. This code describes inflammation of the bone lining (periosteum) around the eye socket (orbit) when the specific side is not documented. This is a bone inflammation condition affecting the structures surrounding the eyeball. H05.039 sits in the ICD-10-CM chapter for diseases of the eye and adnexa (h00-h59), within the section covering disorders of eyelid, lacrimal system and orbit (h00-h05).

H05.039 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

If documentation specifies right or left orbit, use H05.031 (right) or H05.032 (left) instead of the unspecified code H05.039.

Question 2

Is H05.039 an HCC code?

Accepted Answer

No. H05.039 is a billable ICD-10-CM code but does not map to any payment HCC category under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can still be reported on Medicare Advantage encounter data submissions, but it does not contribute to the beneficiary's Risk Adjustment Factor (RAF) score and therefore does not affect the risk-adjusted capitation payment to the plan. V28 reached 100% phase-in for payment year 2026.

Question 3

Is H05.039 billable?

Accepted Answer

Yes. H05.039 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. H05.039 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Question 4

What is the V28 vs V24 difference for H05.039?

Accepted Answer

H05.039 does not map to a payment HCC under either the CMS-HCC V28 risk adjustment model or the older V24 model. V28 reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition. Because neither model rewards H05.039 with a risk adjustment factor, it contributes zero to a Medicare Advantage beneficiary's RAF score in either version. Coders should check whether provider documentation supports a more specific child code that does map to a payment HCC.

Question 5

What should coders know when reporting H05.039?

Accepted Answer

If documentation specifies right or left orbit, use H05.031 (right) or H05.032 (left) instead of the unspecified code H05.039 Periostitis of the orbit is often associated with infection, trauma, or systemic inflammatory conditions—review clinical documentation for underlying cause codes

HCC Buddy Code Card

H05.039

Is H05.039 an HCC code?

What This Code Means

Coding Tips

Child Codes

Code Hierarchy

Open H05.039 in the Interactive Encoder

H05.039 ICD-10-CM Code: Periostitis of unspecified orbit

HCC Buddy Code Card

H05.039

Is H05.039 an HCC code?

What This Code Means

Coding Tips

Child Codes

Code Hierarchy

Open H05.039 in the Interactive Encoder