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ICD-10-CM 2027 diagnosis code

Q85.1Tuberous sclerosis

✓ Billable / specificPOA exemptCC — complication/comorbidity

Q85.1 is a valid, billable ICD-10-CM code for tuberous sclerosis. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Looking up by condition? See ICD-10 code for Epiloia, ICD-10 code for Tuberous sclerosis, ICD-10 code for Bourneville's disease, ICD-10 code for Neurospongioblastosis diffusa.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About Q85.1

Q85.1 is the ICD-10-CM diagnosis code for Tuberous sclerosis. It belongs to category Q85 (phakomatoses, not elsewhere classified), block Q80-Q89 (other congenital malformations) and chapter 17 (congenital malformations, deformations, chromosomal abnormalities, and genetic disorders). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within Q85 (phakomatoses, not elsewhere classified), Q85.1 is specifically for Tuberous sclerosis. Related codes cover neurofibromatosis (nonmalignant) (Q85.0), other phakomatoses, not elsewhere classified (Q85.8) and Phakomatosis, unspecified (Q85.9).

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 091 (Other Disorders of Nervous System with MCC, relative weight 1.7046), DRG 092 (Other Disorders of Nervous System with CC, relative weight 1.0239) and DRG 093 (Other Disorders of Nervous System without CC/MCC, relative weight 0.7783), in MDC 01 (Diseases and Disorders of the Nervous System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It is exempt from present-on-admission (POA) reporting, so no POA indicator is required.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 759.5 (Tuberous sclerosis).

Coding notes

Applicable toConditions and synonyms classified to this code
  • Bourneville's disease
  • Epiloia

Notes that apply from higher levels

Instructions written at a parent level also apply to Q85.1.

› From Q85 Phakomatoses, not elsewhere classified
Excludes1
  • ataxia telangiectasia [Louis-Bar] (G11.3)
  • familial dysautonomia [Riley-Day] (G90.1)

Broader instructions also apply from Chapter 17: Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders.

Alphabetic index entries

12 entries

Terms in the official ICD-10-CM index that lead to Q85.1.

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

ICD-9-CM equivalent

Converter →
  • 759.5Tuberous sclerosisexact

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about Q85.1

Is Q85.1 billable?

Yes. Q85.1 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can Q85.1 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict Q85.1 as a principal diagnosis.

Is Q85.1 a CC or MCC?

Q85.1 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.

What DRG does Q85.1 group to?

Q85.1 is used in the MS-DRG v44.0 logic for MS-DRG 091 (Other Disorders of Nervous System with MCC), MS-DRG 092 (Other Disorders of Nervous System with CC) and MS-DRG 093 (Other Disorders of Nervous System without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

What is the ICD-9 code for Q85.1?

The CMS General Equivalence Mappings map Q85.1 to ICD-9-CM 759.5.