S27.321 – Contusion of lung, unilateral

ICD-10-CM 2027 diagnosis code · Injuries to the thorax

Non-billable header

ICD-10-CM code S27.321

Code: S27.321 (claims format: S27321)
Description: Contusion of lung, unilateral
Billable: No – use a more specific code below
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 19. Injury, poisoning and certain other consequences of external causes (S00-T88)
Block: S20-S29 Injuries to the thorax
Parent codes: S27 › S27.3 › S27.32

Billable codes under S27.321

S27.321 is a header code and cannot be used on claims. Choose the most specific code:

7th character values

Codes in this category need a 7th character to describe the encounter or episode of care.

Character	Meaning
`A`	initial encounter
`D`	subsequent encounter
`S`	sequela

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

S27 – Injury of other and unspecified intrathoracic organs

Excludes2 (not included here):

injury of cervical esophagus (S10-S19)
injury of trachea (cervical) (S10-S19)

Code also:

any associated open wound of thorax (S21.-)

7th character note:

The appropriate 7th character is to be added to each code from category S27

Block S20-S29

Includes:

injuries of breast
injuries of chest (wall)
injuries of interscapular area

Excludes2 (not included here):

burns and corrosions (T20-T32)
effects of foreign body in bronchus (T17.5)
effects of foreign body in esophagus (T18.1)
effects of foreign body in lung (T17.8)
effects of foreign body in trachea (T17.4)
frostbite (T33-T34)
injuries of axilla
injuries of clavicle
injuries of scapular region
injuries of shoulder
insect bite or sting, venomous (T63.4)

Index terms for S27.321

Entries in the ICD-10-CM alphabetic index that lead to this code:

Related codes in S27.32

Frequently asked questions

What is ICD-10 code S27.321?

S27.321 is the ICD-10-CM code for contusion of lung, unilateral, in the block S20-S29 (Injuries to the thorax).

Is S27.321 a billable code?

No. S27.321 is a header code with more specific child codes; report one of the billable codes listed above.

What category does S27.321 belong to?

It belongs to category S27 – Injury of other and unspecified intrathoracic organs.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.