2027 ICD-10-CM Diagnosis Code N25.81Secondary hyperparathyroidism of renal origin

ICD-10-CM Codes›N00–N99›N25-N29›N25

ICD-10-CM N25.81
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

N25.81 is a billable ICD-10-CM diagnosis code for secondary hyperparathyroidism of renal origin. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 698 through 700. 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 269 closely related codes. Coders also document this condition as calcifying panniculitis due to hyperparathyroidism. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified diseases of kidney and ureters.

N25.81 no longer risk-adjusts for Medicare Advantage: it mapped to HCC 23 under the retired CMS-HCC V24 model through payment year 2025 but maps to no category in the live V28 model. It still risk-adjusts in the PACE (CMS-HCC V22) category 23, ESRD (V21) category 23, ESRD (V24) category 23, and RxHCC Part D (V08) category 43 for payment year 2027.

Code Identity

ICD-10-CM Code
N25.81
Billable Status
Yes — Valid for Submission
Code Describes
Secondary hyperparathyroidism of renal origin
Short Description
Secondary hyperparathyroidism of renal origin
Same as the full description in the CMS dataset.
Parent Code
N25.8
Other disorders resulting from impaired renal tubular function

Code Classification

ChapterN00–N99Diseases of the genitourinary system
SectionN25-N29Other disorders of kidney and ureter
CategoryN25Disorders resulting from impaired renal tubular function
This CodeN25.81Secondary hyperparathyroidism of renal origin

Medicare Risk Adjustment (HCC)Billing

N25.81 no longer risk-adjusts for Medicare Advantage: it maps to no payment category in the live CMS-HCC V28 model, although it still risk-adjusts in the other CMS models shown below.

CMS-HCC V28 (Medicare Advantage Payment Model)
Not mapped
Dropped in V28 see all codes that no longer risk-adjust
Prior Model (CMS-HCC V24)
HCC 23
V24 retired last contributed to a Medicare Advantage risk score in payment year 2025
Other CMS Models
PACE (CMS-HCC V22): HCC 23 · ESRD (V21): HCC 23 · ESRD (V24): HCC 23
ESRD V21 weights: 0.013 dialysis, 0.234–0.359 functioning graft · ESRD V24 weights: 0.036 dialysis, 0.217–0.390 functioning graft
Part D (RxHCC)
RxHCC 43 — Pituitary, Adrenal Gland, and Other Endocrine and Metabolic Disorders
also risk-adjusts in the Part D prescription drug model (V08)

Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Calcifying panniculitis due to hyperparathyroidism
  • Calcifying panniculitis due to hyperparathyroidism in renal disease
  • Chronic kidney disease mineral and bone disorder
  • Hyperparathyroidism due to end stage renal disease on dialysis
  • Hyperparathyroidism due to renal insufficiency
  • Renal osteodystrophy
  • Sagliker syndrome
  • Secondary hyperparathyroidism
  • Subcutaneous calcification
  • Uremic secondary hyperparathyroidism

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to N25.81: its own notes plus those printed at block N25-N29 and Chapter 14. A note printed at a category, block or chapter applies to every code under it.

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

  • secondary hyperparathyroidism, non-renal (E21.1)

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.

On N25.81 itself
  • metabolic disorders classifiable to E70-E88
From Block N25-N29 Other disorders of kidney and ureter applies to 22 codes
  • disorders of kidney and ureter with urolithiasis (N20-N23)
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.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name N25.81, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming N25.81: they are not reported together with it, unless the two conditions are unrelated.

  • E21.1 Secondary hyperparathyroidism, not elsewhere classified
    secondary hyperparathyroidism of renal origin (N25.81)

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

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

CCSR GEN006
Other specified and unspecified diseases of kidney and ureters
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Parathyroid Disorders

Most people have four pea-sized glands, called parathyroid glands, on the thyroid gland in the neck. Though their names are similar, the thyroid and parathyroid glands are completely different. The parathyroid glands make parathyroid hormone (PTH), which helps your body keep the right balance of calcium and phosphorous.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert N25.81 to ICD-9-CMHistory

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

ICD-9-CM
588.81 Sec hyperparathyrd-renal
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About N25.81Overview

What is the ICD-10 code for secondary hyperparathyroidism of renal origin?

The ICD-10-CM code for secondary hyperparathyroidism of renal origin is N25.81 (sometimes written as N2581). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is N25.81 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report secondary hyperparathyroidism of renal origin on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does N25.81 group to?

When secondary hyperparathyroidism of renal origin is the principal diagnosis on an inpatient stay, it groups to MS-DRG 699, 698, 700, with relative weights from 0.6740 to 1.6400 depending on complications. Higher weights mean higher Medicare reimbursement.

Is N25.81 a CC or MCC?

CMS lists N25.81 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 269 closely related codes in its exclusion list.

Can N25.81 be reported with E21.1?

Not as a rule. The Excludes1 note on N25.81 lists "secondary hyperparathyroidism, non-renal (E21.1)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

Does N25.81 risk-adjust for Medicare Advantage payment?

Not for Medicare Advantage. N25.81 mapped to HCC 23 in the retired CMS-HCC V24 model, which last determined payment in 2025, but it maps to no category in the live V28 model; see all codes that no longer risk-adjust. It still risk-adjusts in the PACE (CMS-HCC V22) category 23 (Other Significant Endocrine and Metabolic Disorders), ESRD (V21) category 23 (Other Significant Endocrine and Metabolic Disorders), ESRD (V24) category 23 (Other Significant Endocrine and Metabolic Disorders), and RxHCC Part D (V08) category 43 (Pituitary, Adrenal Gland, and Other Endocrine and Metabolic Disorders).