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F84.9 ICD-10-CM Code: Pervasive developmental disorder, unspecified

F84.9 is not a CMS-HCC payment code. MEAT criteria · RAF calculator · free HCC coding tools

ICD-10-CM Code View

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FY 2026 Apr update / Mental, Behavioral and Neurodevelopmental disorders (F01-F99) / Pervasive and specific developmental disorders (F80-F89)

F84.9

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Pervasive developmental disorder, unspecified

A pervasive developmental disorder affecting social communication and behavior, but the specific type cannot be determined or is not further specified.

Buddy the Bee presenting code insight

Buddy Insight

Unspecified pervasive developmental disorder is used when the provider documents a PDD/autism spectrum condition but does not specify the type.

CMS-HCC V28

N/A

—

Not mapped

CMS-HCC V24

N/A

—

Not mapped

ACA/HHS

HCC 103

Varies by metal level

ESRD/PACE

N/A

—

Not mapped

RXHCC

HCC 133

RAF 0.035

Code Book Path

Official
F84Pervasive developmental disorders
F84.9Pervasive developmental disorder, unspecified

Inclusion Terms

Official
  • Atypical autism

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for F84.9 in this effective period.

Related Child Codes

Official
F84.0Autistic disorder
F84.2Rett's syndrome
F84.3Other childhood disintegrative disorder
F84.5Asperger's syndrome
F84.8Other pervasive developmental disorders

Includes

Official

ICD-10-CM does not list Includes notes for F84.9 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for F84.9 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for F84.9 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for F84.9 in this effective period.

Code Also

Official
  • any associated medical condition and intellectual disabilities

Buddy Documentation Tip

HCC Buddy guidance
Provider documentation of a pervasive developmental disorder
Evidence of social communication deficits and/or restricted repetitive behaviors
Documentation that the condition does not fully meet criteria for a specific PDD category, or that the specific type has not been determined
Query opportunity — if possible, clarify with the provider whether the diagnosis meets criteria for F84.0 (autism) or F84.5 (Asperger's)

MEAT Support

HCC Buddy guidance
Provider documentation of a pervasive developmental disorder
Evidence of social communication deficits and/or restricted repetitive behaviors
Documentation that the condition does not fully meet criteria for a specific PDD category, or that the specific type has not been determined
Query opportunity — if possible, clarify with the provider whether the diagnosis meets criteria for F84.0 (autism) or F84.5 (Asperger's)

Audit Caution

HCC Buddy guidance
Using F84.9 when the provider has documented a specific PDD type — always select the most specific code available
Failing to query for specificity when the documentation suggests a particular PDD subtype
Continuing to code F84.9 when updated evaluations have established a specific diagnosis
Not coding comorbid conditions (intellectual disability, ADHD, anxiety) that frequently co-occur

Common Mistakes

HCC Buddy guidance
F84.0 — Autistic disorder; if autism/ASD is documented, use F84.0, not the unspecified code
F84.5 — Asperger's syndrome; if Asperger's is documented, use the specific code
F84.8 — Other pervasive developmental disorders; for specific atypical PDD presentations
F88 — Other disorders of psychological development; for developmental issues not meeting PDD criteria

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is F84.9 an HCC code?

F84.9 is not in the CMS-HCC V28 or V24 community payment model, but it does map to Personality Disorders, Anxiety, and Other Specified Mental Disorders under the Part D RxHCC model.

Code
F84.9
Description
Pervasive developmental disorder, unspecified
HCC (V28)
No CMS-HCC V28 mapping
RAF
—
Billable
Yes
Payment year
2026

HCC Category Mapping

RxHCCHCC 133, Personality Disorders, Anxiety, and Other Specified Mental Disorders
0.035

Each model's RAF is its CMS base weight for that model's standard population, so weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.

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MEAT Criteria for F84.9

For F84.9 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

  • MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
  • EEvaluate: test results, medication response, or physical findings reviewed by the provider
  • AAssess: explicit mention in the assessment or plan with acknowledgment of status
  • TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed F84.9 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

F84.9 is the ICD-10-CM diagnosis code for pervasive developmental disorder, unspecified. A pervasive developmental disorder affecting social communication and behavior, but the specific type cannot be determined or is not further specified. F84.9 sits in the ICD-10-CM chapter for mental, behavioral and neurodevelopmental disorders (f01-f99), within the section covering pervasive and specific developmental disorders (f80-f89).

F84.9 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

This code does not map to a CMS-HCC V28 payment category. Capture depends on documentation that supports the diagnosis; verify the HCC assignment against the current CMS mapping for the applicable payment year. Coders reviewing F84.9 should check whether additional documentation would support a more specific child code in the same hierarchy that does map to a payment HCC, capturing the correct specificity is the highest-impact RAF improvement available within accurate coding.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for F84.9 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

  • •This is the least specific code in the F84 category; attempt to use more specific codes when possible
  • •Review clinical documentation for features that would allow assignment of F84.0, F84.2, F84.3, or F84.5

Clinical Significance

Unspecified pervasive developmental disorder is used when the provider documents a PDD/autism spectrum condition but does not specify the type. This was historically used for 'PDD-NOS' (pervasive developmental disorder not otherwise specified) and may still appear in records of patients diagnosed under DSM-IV criteria. While clinically valid, pursuing specificity improves care planning.

Documentation Requirements

  • ✓Provider documentation of a pervasive developmental disorder
  • ✓Evidence of social communication deficits and/or restricted repetitive behaviors
  • ✓Documentation that the condition does not fully meet criteria for a specific PDD category, or that the specific type has not been determined
  • ✓Query opportunity — if possible, clarify with the provider whether the diagnosis meets criteria for F84.0 (autism) or F84.5 (Asperger's)
  • ✓Current treatment plan and functional status documentation

Commonly Confused Codes

  • •F84.0: Autistic disorder; if autism/ASD is documented, use F84.0, not the unspecified code
  • •F84.5: Asperger's syndrome; if Asperger's is documented, use the specific code
  • •F84.8: Other pervasive developmental disorders; for specific atypical PDD presentations
  • •F88: Other disorders of psychological development; for developmental issues not meeting PDD criteria

Child Codes

F84.0Autistic disorder
F84.2Rett's syndrome
F84.3Other childhood disintegrative disorder
F84.5Asperger's syndrome
F84.8Other pervasive developmental disorders
F84.9Pervasive developmental disorder, unspecified

Code Hierarchy

└F84Pervasive developmental disorders└F84.9Pervasive developmental disorder, unspecified
└F84.9Pervasive developmental disorder, unspecified

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