ICD-10-CM 2027 diagnosis code
I80.00Phlebitis and thrombophlebitis of superficial vessels of unspecified lower extremity
I80.00 is a valid, billable ICD-10-CM code for phlebitis and thrombophlebitis of superficial vessels of unspecified lower extremity. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.Short description: Phlbts and thombophlb of superfic vessels of unsp low extrm
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About I80.00
I80.00 is the ICD-10-CM diagnosis code for phlebitis and thrombophlebitis of superficial vessels of unspecified lower extremity. It belongs to category I80 (phlebitis and thrombophlebitis), block I80-I89 (diseases of veins, lymphatic vessels and lymph nodes, not elsewhere classified) and chapter 9 (diseases of the circulatory system). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.
Within I80.0, choose I80.00 (unspecified lower extremity) only when documentation doesn't support a more specific option: right lower extremity (I80.01), left lower extremity (I80.02) and bilateral (I80.03).
Code first: , if applicable: phlebitis and thrombophlebitis complicating abortion, ectopic or molar pregnancy (O00-O07, O08.7) and phlebitis and thrombophlebitis complicating pregnancy, childbirth and the puerperium (O22.-, O87.-).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 299 (Peripheral Vascular Disorders with MCC, relative weight 1.5842), DRG 300 (Peripheral Vascular Disorders with CC, relative weight 1.0464) and DRG 301 (Peripheral Vascular Disorders without CC/MCC, relative weight 0.7133), in MDC 05 (Diseases and Disorders of the Circulatory System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
Before ICD-10, this condition was coded in ICD-9-CM as 451.0 (phlebitis and thrombophlebitis of superficial vessels of lower extremities).
Notes that apply from higher levels
Instructions written at a parent level also apply to I80.00.
› From I80 Phlebitis and thrombophlebitis
- endophlebitis
- inflammation, vein
- periphlebitis
- suppurative phlebitis
Broader instructions also apply from Chapter 9: Diseases of the circulatory system.
MS-DRG v44.0 grouping
All DRGs →Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.
MDC 05 · Diseases and Disorders of the Circulatory System
ICD-9-CM equivalent
Converter →- 451.0Phlebitis and thrombophlebitis of superficial vessels of lower extremitiesapproximate
From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about I80.00
Is I80.00 billable?
- Yes. I80.00 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can I80.00 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict I80.00 as a principal diagnosis.
Is I80.00 a CC or MCC?
- No. I80.00 is neither a CC nor an MCC under MS-DRG v44.0.
What DRG does I80.00 group to?
- I80.00 is used in the MS-DRG v44.0 logic for MS-DRG 299 (Peripheral Vascular Disorders with MCC), MS-DRG 300 (Peripheral Vascular Disorders with CC) and MS-DRG 301 (Peripheral Vascular Disorders without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.
What is the ICD-9 code for I80.00?
- The CMS General Equivalence Mappings map I80.00 to ICD-9-CM 451.0.