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ICD-10-CM 2027 diagnosis code

F78.A1SYNGAP1-related intellectual disability

✓ Billable / specific

F78.A1 is a valid, billable ICD-10-CM code for syngap1-related intellectual disability. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Code last changed in FY2022 (effective October 1, 2021). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About F78.A1

F78.A1 is the ICD-10-CM diagnosis code for SYNGAP1-related intellectual disability. It belongs to category F78 (other intellectual disabilities), block F70-F79 (intellectual Disabilities) and chapter 5 (mental, Behavioral and Neurodevelopmental 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 F78.A (other genetic related intellectual disabilities), F78.A1 is specifically for SYNGAP1-related intellectual disability. Related codes cover other genetic related intellectual disability (F78.A9).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 884 (Organic Disturbances and Intellectual Disability, relative weight 1.6001), in MDC 19 (Mental Diseases and Disorders), 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 was added in FY2022, effective October 1, 2021.

Coding notes

Code alsoTwo codes may be needed; sequencing depends on circumstances
  • , if applicable, any associated:
  • autism spectrum disorder (F84.0)
  • autistic disorder (F84.0)
  • encephalopathy (G93.4-)
  • epilepsy and recurrent seizures (G40.-)
  • other pervasive developmental disorders (F84.8)
  • pervasive developmental disorder, NOS (F84.9)

Notes that apply from higher levels

Instructions written at a parent level also apply to F78.A1.

Broader instructions also apply from F70-F79 Intellectual Disabilities and Chapter 5: Mental, Behavioral and Neurodevelopmental disorders.

Alphabetic index entries

4 entries

Terms in the official ICD-10-CM index that lead to F78.A1.

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.

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
  • FY2022 (effective 10/1/2021): Added
  • No changes since FY2022.

Common questions about F78.A1

Is F78.A1 billable?

Yes. F78.A1 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can F78.A1 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict F78.A1 as a principal diagnosis.

Is F78.A1 a CC or MCC?

No. F78.A1 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does F78.A1 group to?

F78.A1 is used in the MS-DRG v44.0 logic for MS-DRG 884 (Organic Disturbances and Intellectual Disability). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.