ICD code S00.222D – Left eyelid nonthermal blister, subsequent encounter

Key takeaways

S00.222D codes a nonthermal blister of the left eyelid or periocular area at a subsequent encounter, when the patient is back for routine healing-phase care.

Use S00.221D for the right side, S00.229D when no side is documented, and S00.222A while the blister is still under active treatment.

A blister caused by heat is a burn (T26.02X-), one caused by a chemical is a corrosion (T26.52X-), and a bruised left eyelid is S00.12X-.

Before the claim is built, the note should name the left side, a nonthermal cause, and a follow-up visit in the healing phase.

ICD-10 code S00.222D: Definition and billable status

ICD-10 code S00.222D is the billable ICD-10-CM code for blister (nonthermal) of left eyelid and periocular area, subsequent encounter. It applies when a blister on the left eyelid or the skin around the left eye was caused by friction, pressure, or minor trauma. The patient has finished active treatment and is back for routine care while it heals.

The code sits in the injury chapter, under superficial injuries of the head. It is listed as billable in the FY2026 ICD-10-CM tabular list, so it can go on a claim as written.

Code details at a glance

The 7th character D and the subsequent encounter rule

The D in S00.222D marks a subsequent encounter. Per the ICD-10-CM Official Guidelines, Section I.C.19.a, D applies after the patient has completed active treatment. It covers routine care for the injury during the healing or recovery phase.

The 7th character follows the phase of care, not the number of visits or the clinician. A patient seen by a new physician who is still actively treating the blister keeps the A character. A patient back at the original practice for a healing check moves to D.

Do not swap the injury code for an aftercare Z code at these visits. The guidelines direct you to report the injury code itself with the D character for healing-phase care.

Clinical description: Nonthermal blister of the left eyelid

A nonthermal blister is a fluid-filled pocket that forms when the outer layers of skin separate after friction, pressure, or minor trauma. On the eyelid and periocular area it can follow rubbing from goggles, a tight mask strap, or a glancing injury. The periocular area takes in the skin of both lids and the tissue surrounding the eye socket.

The word nonthermal does the classifying work. ICD-10-CM keeps heat and chemical blisters out of this subcategory and codes them as burns or corrosions instead. Blisters that come from a disease, such as shingles or an allergic reaction, are coded to that condition, not to an injury code.

Typical follow-up findings for S00.222D include:

• A left eyelid blister that has been drained or has ruptured, now being checked for healing
• A dressing change on the left periocular skin after the first treatment visit
• A review for signs of infection while the blistered skin re-epithelializes

Code hierarchy and classification for S00.222D

Each level of the code narrows the diagnosis until the 7th character finishes it. Only the full seven-character code is billable.

S00.222D vs related codes: Side, phase and cause

Most coding errors on this code come from three choices made out of order. Settle the cause of the blister first, then the side, then the phase of care, as the diagram below lays out.

The table below lists the siblings in S00.22- and the codes this one is most often confused with.

When the note says only “eyelid blister”, query the provider for the side before you settle on S00.229D. A specific code supported by the record is always preferred over an unspecified one.

Excludes notes and coding restrictions

The tabular list carries notes at several levels above S00.222D. Each one changes what you can report alongside it.

Excludes1 at category S00

Category S00 excludes injury of eye and orbit (S05.-) and open wound of head (S01.-). If the skin over the left eyelid is broken into an open wound, code the wound from S01.1- instead.

Excludes2 at subcategory S00.2

Subcategory S00.2 has an Excludes2 note for superficial injury of conjunctiva and cornea (S05.0-). Both can be reported together when the patient has a left eyelid blister and a separate injury to the surface of the eye.

Superficial injury rule

Section I.C.19.b of the guidelines says superficial injuries are not coded when they accompany a more severe injury of the same site. If a deeper injury of the left eyelid is documented, that code takes the place of S00.222D.

Documentation tips for accurate S00.222D coding

Per the CMS ICD-10-CM Official Guidelines, the record must support each element of the code. Before submitting a clean claim, confirm these points in the note:

1. Left side named. The note says “left eyelid” or “left periocular area”, not just “eyelid”.
2. Blister, not bruise or wound. The finding is a blister, with no open wound and no contusion recorded as the main injury.
3. Nonthermal cause. The mechanism is friction, pressure, or trauma, with no heat or chemical exposure documented.
4. Healing phase. Active treatment is complete and the visit is routine follow-up care.
5. External cause recorded. The note says how the blister happened, so Chapter 20 codes can be added where the payer expects them.

External cause codes at a subsequent encounter

External cause codes from Chapter 20 explain how the injury happened. The CDC/NCHS ICD-10-CM tool lists them alongside the injury chapter. Per Section I.C.20, an external cause code may be reported at each encounter while the injury is being treated, with the matching 7th character.

• Cause: the mechanism, such as friction from equipment or contact with an object
• Place of occurrence (Y92): reported once, at the initial encounter only
• Activity (Y93): reported once, at the initial encounter only
• External cause status (Y99): reported once, at the initial encounter only

That means a D visit may carry the cause code with its own D character. The place, activity, and status codes stay off it, so a status code such as Y99.8 belongs on the initial claim only. No national rule requires external cause codes, so check your payer and state reporting rules.

Billing and reimbursement guidelines for S00.222D

S00.222D does not trigger prior authorization by itself. Authorization rules attach to the service billed with the diagnosis. Payers do expect the note to support the subsequent-encounter designation and the left side.

Denials on this code usually trace back to the 7th character, the side, or a truncated code. Effective denial management workflows treat each one as its own root cause.

A denied S00.222D claim comes back with an adjustment reason code on the remittance. Check it against our list of medical billing denial codes to see which row of the table applies.

Medicare and Medicaid follow the ICD-10-CM Official Guidelines for 7th character selection. Commercial payers generally mirror them, though local coverage policies can add documentation requirements. The AAPC ICD-10-CM code range lookup is a quick way to check neighboring codes before you resubmit.

How Pabau handles the claim once the code is right

Picking the right 7th character and side is the coder’s job. What happens to the claim afterward often sits in a separate portal, and the remittance arrives somewhere else again. Someone then rekeys the outcome into the patient record days later.

Pabau, the practice management and billing platform we build, keeps that chain in one record. It submits electronic claims through the Claim.MD clearinghouse and checks eligibility with 270/271 transactions before the visit.

It tracks each claim’s status and posts electronic remittance advice back to the patient record. Validation of required claim fields stops an incomplete claim before it goes out.

Your billing team then works from one record instead of three, which is the job of claims management software. When an S00.222D claim comes back, you see it next to the note that produced it. You can correct the code and resubmit in the same sitting.

Keep coding, claims, and remittance in one system

Pabau submits claims through Claim.MD, checks eligibility before the visit, tracks claim status, and posts remittance back to the patient record.

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Conclusion

S00.222D carries three decisions in one code: a nonthermal blister, the left side, and a healing-phase visit. Get any one wrong and a different code applies, from S00.221D to S00.222A to T26.02XD. The note has to support all three before the claim is built.

The cheapest fix is at the point of documentation. A minute spent confirming the cause and the phase of care costs far less than a rejected claim and a second wait for payment.

Want the note, the claim, and the remittance in one place? Book a demo and we’ll walk your billing team through it.

Continue your research

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