Alphabetic Index FY2027

Q85.1

Tuberous sclerosis

FY2027Chapter 17: Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders/Q80–Q89 Other congenital malformations

BillableComplete code, valid to report
Care settingsHome Health Primary · MMTA - OtherHospital CC

Q85.1 (also written Q851) is a billable ICD-10-CM diagnosis code for tuberous sclerosis. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 11 codes in category Q85 (Phakomatoses, not elsewhere classified). The Alphabetic Index lists it under 12 entries. Its coding notes include 2 Excludes1 entries and 1 Excludes2 entry.

Guidelines tip

From the FY2027 Official Guidelines. ICD10Ref adds no rules of its own.

Chapter 17 codes can be used for life. Manifestations that are an inherent part of a specifically coded anomaly are not coded separately. A corrected malformation is reported with a personal history code.

Guidelines I.C.17Congenital malformations and genetic disordersRead the official text

Excludes1

Not coded here. The listed conditions generally should not be reported together.

Inherited from Q85 Phakomatoses, not elsewhere classified
  • ataxia telangiectasia [Louis-Bar] (G11.3)
  • familial dysautonomia [Riley-Day] (G90.1)

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

Also from chapter/block level (1 note)
Inherited from Chapter 17 Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders
  • inborn errors of metabolism (E70-E88)

Care settings

How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.

Home Health Primary

Accepted as the primary (principal) diagnosis on a home health claim. The Home Health Grouper assigns it to the MMTA - Other clinical group.

Source: CMS Home Health Grouper Software v07.2.26, effective October 1, 2026

Hospital CC

Counts as a complication or comorbidity (CC) when reported as a secondary diagnosis on an inpatient claim. It does not count when the principal diagnosis is one of the 8 codes in its exclusion list. Some MS-DRGs also ignore a CC or MCC that defines the DRG.

Source: CMS MS-DRG Definitions Manual v44, effective October 1, 2026, Appendix C

Inclusion terms

Conditions classified to this code.

This code
  • Bourneville's disease
  • Epiloia

Notes

Also from chapter/block level (1 note)
Inherited from Chapter 17 Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders
  • Codes from this chapter are not for use on maternal records

Alphabetic Index terms

Terms the official Alphabetic Index lists for this code. 12 entries