DxCodebookFY2027 · Oct 1, 2026 – Sep 30, 2027

N12 diagnosis code · Billable category · FY2027

N12 Tubulo-interstitial nephritis, not specified as acute or chronic

  • Billable
  • CC
  • POA reported

N12 ICD-10 code: a billable diagnosis code in FY2027; the category has no subdivisions.

Where it sits

  1. Chapter 14 Diseases of the genitourinary system (N00-N99)
  2. N10-N16 Renal tubulo-interstitial diseases (N10-N16)
  3. N12 Tubulo-interstitial nephritis, not specified as acute or chronic
CC / MCC
CC
MS-DRG
689-690, 791, 793
HCC V28
–
POA
Reported
Code Editor
–
Index entries
6

Instructions

At N12

Inclusion terms

  • Interstitial nephritis NOS
  • Pyelitis NOS
  • Pyelonephritis NOS

Excludes1

  • calculous pyelonephritis (N20.9) N20.9

Notes that also apply

Block N10-N16 instructions (Includes 1, Excludes1 1): printed on the block page.

Chapter 14 instructions (Excludes2 8): printed on the chapter 14 page.

Index entries

  • Pyonephritis → N12
  • Nephritis, nephritic (albuminuric) (azotemic) (congenital) (disseminated) (epithelial) (familial) (focal) (granulomatous) (hemorrhagic) (infantile) (nonsuppurative, excretory) (uremic)antitubular basement membrane (tubulo-interstitial) NEC → N12
  • Nephritis, nephritic (albuminuric) (azotemic) (congenital) (disseminated) (epithelial) (familial) (focal) (granulomatous) (hemorrhagic) (infantile) (nonsuppurative, excretory) (uremic)tubulo-interstitial (in) → N12
  • Pyelonephritisnonobstructive → N12
  • Disease, diseasedantiglomerular basement membrane (anti- GBM) antibodytubulo-interstitial nephritis → N12
  • Disease, diseasedrenal (functional) (pelvis)withinterstitial nephritis → N12

NCHS Alphabetic Index. Index first, then the Tabular List.

Medicare grouping and edits

CMS files for N12
CC / MCCCC
PDX exclusion list1328 (228 codes)
Appendix BMDC 11 Diseases and Disorders of the Kidney and Urinary Tract, MS-DRG 689-690 (Kidney and Urinary Tract Infections with MCC…); MDC 15 Newborns and Other Neonates with Conditions Originating in Perinatal Period, MS-DRG 791 (Prematurity with Major Problems…); MDC 15 Newborns and Other Neonates with Conditions Originating in Perinatal Period, MS-DRG 793 (Full Term Neonate with Major Problems…)
Code Editor–
POAReported
HCC V28–

CC as a secondary diagnosis, not when the principal diagnosis is on its PDX exclusion list.

CMS: MS-DRG v44 (Appendix B, C), MCE v44, POA list FY2027, 2027 Initial ICD-10-CM Mappings. What the rows mean.

Hierarchy