S82.399N — Other fracture of lower end of unspecified tibia, subsequent encounter for open fracture type IIIA, IIIB, or IIIC with nonunion
Is S82.399N billable?
Yes, but S82.399N will trip a Medicare edit. S82.399N is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, CMS lists S82.399N under Medicare Code Editor edit 20, “Unspecified code” — meaning a code specifying laterality (right, left or bilateral) exists in the same family. On an inpatient claim this triggers the edit, because CMS holds that there are very limited circumstances in which laterality cannot be documented.
S82.399N at a glance
| Code | S82.399N |
|---|---|
| Description | Other fracture of lower end of unspecified tibia, subsequent encounter for open fracture type IIIA, IIIB, or IIIC with nonunion |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
| 7th character "N" | subsequent encounter for open fracture type IIIA, IIIB, or IIIC with nonunion |
What does the 7th character "N" mean in S82.399N?
In S82.399N, the 7th character N means subsequent encounter for open fracture type IIIA, IIIB, or IIIC with nonunion. The 7th character is required for S82.399N to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
- Ainitial encounter for closed fractureS82.399A
- Binitial encounter for open fracture type I or IIS82.399B
- Cinitial encounter for open fracture type IIIA, IIIB, or IIICS82.399C
- Dsubsequent encounter for closed fracture with routine healingS82.399D
- Esubsequent encounter for open fracture type I or II with routine healingS82.399E
- Fsubsequent encounter for open fracture type IIIA, IIIB, or IIIC with routine healingS82.399F
- Gsubsequent encounter for closed fracture with delayed healingS82.399G
- Hsubsequent encounter for open fracture type I or II with delayed healingS82.399H
- Jsubsequent encounter for open fracture type IIIA, IIIB, or IIIC with delayed healingS82.399J
- Ksubsequent encounter for closed fracture with nonunionS82.399K
- Msubsequent encounter for open fracture type I or II with nonunionS82.399M
- Nsubsequent encounter for open fracture type IIIA, IIIB, or IIIC with nonunionS82.399N
- Psubsequent encounter for closed fracture with malunionS82.399P
- Qsubsequent encounter for open fracture type I or II with malunionS82.399Q
- Rsubsequent encounter for open fracture type IIIA, IIIB, or IIIC with malunionS82.399R
- SsequelaS82.399S
What Medicare edits apply to S82.399N?
The Medicare Code Editor screens inpatient claims before they are grouped. These edits name S82.399N directly.
A code specifying laterality (right, left or bilateral) exists in the same family. CMS holds that there are very limited circumstances in which laterality cannot be documented.
Which MS-DRGs does S82.399N group to?
S82.399N sits in MDC 08 and helps define the logic of 3 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 564Other Musculoskeletal System and Connective Tissue Diagnoses with MCCmedical
- 565Other Musculoskeletal System and Connective Tissue Diagnoses with CCmedical
- 566Other Musculoskeletal System and Connective Tissue Diagnoses without CC/MCCmedical
As a secondary diagnosis, S82.399N is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.
How is S82.399N listed in the Alphabetic Index?
The Alphabetic Index lists these routes under S82.39, the nearest indexed parent of S82.399N. Use them to find the family, then select the specific code.
- Fracture, traumatic › tibia › lower end › specified NEC (abduction) (adduction) (separation)
Excludes1 — never code together — inherited from S82
The conditions below can never be reported together with S82.399N on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- traumatic amputation of lower leg (S88.-)
Excludes1 — never code together — inherited from S82.3
The conditions below can never be reported together with S82.399N 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 S82.399N to fully describe the condition. S82.399N 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 S82.399N, but a patient may have both at the same time. When documentation supports it, S82.399N and the excluded code may both be reported.
Excludes2 — not included here — inherited from S80-S89
The conditions below are not part of S82.399N, but a patient may have both at the same time. When documentation supports it, S82.399N and the excluded code may both be reported.
Excludes2 — not included here — inherited from S82
The conditions below are not part of S82.399N, but a patient may have both at the same time. When documentation supports it, S82.399N and the excluded code may both be reported.
How long has S82.399N existed?
S82.399N 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.