2027 ICD-10-CM Diagnosis Code N83.521Torsion of right fallopian tube

ICD-10-CM Codes›N00–N99›N80-N98›N83

ICD-10-CM N83.521
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

N83.521 is a billable ICD-10-CM diagnosis code for torsion of right fallopian tube. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 742 through 743, 760 through 761. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 36 closely related codes. Coders also document this condition as torsion of fallopian tube. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified female genital disorders.

Code Identity

ICD-10-CM Code
N83.521
Billable Status
Yes — Valid for Submission
Code Describes
Torsion of right fallopian tube
Short Description
Torsion of right fallopian tube
Same as the full description in the CMS dataset.
Parent Code
N83.52
Torsion of fallopian tube

Code Classification

ChapterN00–N99Diseases of the genitourinary system
SectionN80-N98Noninflammatory disorders of female genital tract
CategoryN83Noninflammatory disorders of ovary, fallopian tube and broad ligament
This CodeN83.521Torsion of right fallopian tube

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Torsion of fallopian tube
  • Torsion of right fallopian tube

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to N83.521: its own notes plus those printed at N83 and Chapter 14. A note printed at a category, block or chapter applies to every code under it.

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From N83 Noninflammatory disorders of ovary, fallopian tube and broad ligament applies to 35 codes
From Chapter 14 (N00-N99) Diseases of the genitourinary system applies to 838 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR GEN025
Other specified female genital disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Convert N83.521 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
620.5 Torsion of ovary or tube
Approximate The match is approximate rather than exact.

Code History & ChangesHistory

Replacement N83.521 replaces the following previously assigned code(s):

  • N83.52 - Torsion of fallopian tube
FY 2019AddedAdded to the ICD-10-CM code setEffective October 1, 2018.
FY 2020–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About N83.521Overview

What is the ICD-10 code for torsion of right fallopian tube?

The ICD-10-CM code for torsion of right fallopian tube is N83.521 (sometimes written as N83521). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is N83.521 (Torsion of fallopian tube) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report torsion of right fallopian tube on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does N83.521 group to?

When torsion of right fallopian tube is the principal diagnosis on an inpatient stay, it groups to MS-DRG 742, 743, 760, 761, with relative weights from 0.7039 to 1.8448 depending on complications. Higher weights mean higher Medicare reimbursement.

Is N83.521 a CC or MCC?

CMS lists N83.521 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 36 closely related codes in its exclusion list.

What is the ICD-9 equivalent of N83.521?

Under the General Equivalence Mappings, torsion of right fallopian tube converts to ICD-9-CM 620.5 (torsion of ovary or tube). The mapping is approximate, so confirm the match fits the documentation.