O91.21

Non-Billable
ChapterO00–O9A
Ranksubcategory
Official Description

Nonpurulent mastitis associated with pregnancy

Metadata & Insights
  • Non-billable category (requires more specific sub-code).
  • Chapter 15: Pregnancy, Childbirth and the Puerperium (O00-O9A).

Instructional Notes

Includes
  • Gestational interstitial mastitis
  • Gestational lymphangitis of breast
  • Gestational mastitis NOS
  • Gestational parenchymatous mastitis
General instructions are available for the parent sections:

Clinical Hierarchy

BillableHas subcodes
CH15Pregnancy, childbirth and the puerperium (O00-O9A)
O85-O92Complications predominantly related to the puerperium (O85-O92)
O91Infections of breast associated with pregnancy, the puerperium and lactation
O91.2Nonpurulent mastitis associated with pregnancy, the puerperium and lactation
O91.21Nonpurulent mastitis associated with pregnancyNot billable
O91.211Nonpurulent mastitis associated with pregnancy, first trimesterBillable
O91.212Nonpurulent mastitis associated with pregnancy, second trimesterBillable
O91.213Nonpurulent mastitis associated with pregnancy, third trimesterBillable
O91.219Nonpurulent mastitis associated with pregnancy, unspecified trimesterBillable

Applicable Ancestor Context

The following parent sections contain instructions or notes that apply to O91.21:

categoryO91
Infections of breast associated with pregnancy, the puerperium and lactation
View context instructions
blockO85-O92
Complications predominantly related to the puerperium (O85-O92)
View context instructions
chapterCH15
Pregnancy, childbirth and the puerperium (O00-O9A)
View context instructions

MS-DRG Classification

2026

No direct MS-DRG triggers identified.

Cross Reference

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