S00.429A — Blister (nonthermal) of unspecified ear, initial encounter
Is S00.429A billable?
Yes, but S00.429A is an unspecified code. S00.429A is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, S00.429A is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting S00.429A — the more specific alternatives are listed below.
S00.429A at a glance
| Code | S00.429A |
|---|---|
| Description | Blister (nonthermal) of unspecified ear, initial encounter |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
| 7th character "A" | initial encounter |
What does the 7th character "A" mean in S00.429A?
In S00.429A, the 7th character A means initial encounter. The 7th character is required for S00.429A to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
Which MS-DRGs does S00.429A group to?
S00.429A sits in MDC 09 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 606Minor Skin Disorders with MCCmedical
- 607Minor Skin Disorders without MCCmedical
How is S00.429A listed in the Alphabetic Index?
The Alphabetic Index lists these routes under S00.42, the nearest indexed parent of S00.429A. Use them to find the family, then select the specific code.
- Blister › ear (nonthermal)
Excludes1 — never code together — inherited from S00
The conditions below can never be reported together with S00.429A on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
Use additional code — inherited from Chapter 19
Report an additional code alongside S00.429A to fully describe the condition. S00.429A is sequenced first.
- code to identify any retained foreign body, if applicable (Z18.-)
Excludes2 — not included here — inherited from Chapter 19
The conditions below are not part of S00.429A, but a patient may have both at the same time. When documentation supports it, S00.429A and the excluded code may both be reported.
Excludes2 — not included here — inherited from S00-S09
The conditions below are not part of S00.429A, but a patient may have both at the same time. When documentation supports it, S00.429A and the excluded code may both be reported.
- burns and corrosions (T20-T32)
- effects of foreign body in ear (T16)
- effects of foreign body in larynx (T17.3)
- effects of foreign body in mouth NOS (T18.0)
- effects of foreign body in nose (T17.0-T17.1)
- effects of foreign body in pharynx (T17.2)
- effects of foreign body on external eye (T15.-)
- frostbite (T33-T34)
- insect bite or sting, venomous (T63.4)
Code also — inherited from S00-S09
Two codes may be needed to describe the condition fully. Whether S00.429A is sequenced first depends on the reason for the encounter.
- for any associated infection
How long has S00.429A existed?
S00.429A has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.