S90.421 — Blister (nonthermal), right great toe

Not billable

Is S90.421 billable?

No — S90.421 is a non-billable header code. S90.421 groups more specific codes and cannot be submitted on a claim. A valid ICD-10-CM code must be reported at the highest level of specificity available in its branch. Select one of the 3 billable codes beneath S90.421.

Billable codes under this header

S90.421 at a glance

Code	S90.421
Description	Blister (nonthermal), right great toe
Billable	No — header code
Code set	ICD-10-CM FY2027
Valid for encounters	October 1, 2026 – September 30, 2027

How is S90.421 listed in the Alphabetic Index?

The Alphabetic Index lists these routes under S90.42, the nearest indexed parent of S90.421. Use them to find the family, then select the specific code.

Blister › toe (nonthermal)
Blister › toe › great (nonthermal)

Use additional code — inherited from Chapter 19

Report an additional code alongside S90.421 to fully describe the condition. S90.421 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 S90.421, but a patient may have both at the same time. When documentation supports it, S90.421 and the excluded code may both be reported.

birth trauma (P10-P15)
obstetric trauma (O70-O71)

Excludes2 — not included here — inherited from S90-S99

The conditions below are not part of S90.421, but a patient may have both at the same time. When documentation supports it, S90.421 and the excluded code may both be reported.

burns and corrosions (T20-T32)
fracture of ankle and malleolus (S82.-)
frostbite (T33-T34)
insect bite or sting, venomous (T63.4)

What codes fall under S90.421? (3)

How long has S90.421 existed?

S90.421 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.