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F21 ICD-10-CM Code: Schizotypal disorder

F21 maps to CMS-HCC V28 153. A source-labeled RAF reference is available. Confirm the documented diagnosis and applicable coding requirements. MEAT criteria · RAF Calculator · free HCC coding tools

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Code lookupF21

FY 2026 Apr update / Mental, Behavioral and Neurodevelopmental disorders (F01-F99) / Schizophrenia, schizotypal, delusional, and other non-mood psychotic disorders (F20-F29)

F21

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

Schizotypal disorder

A personality disorder characterized by odd beliefs, unusual perceptual experiences, and eccentric behavior, but without the full psychotic symptoms seen in schizophrenia.

Buddy the Bee presenting code insight

Buddy Insight

Schizotypal disorder is a personality disorder characterized by eccentric behavior, odd beliefs (magical thinking), unusual perceptual experiences, and social deficits without the full psychotic symptoms of schizophrenia.

OverviewRisk ModelsCode BookDocumentationAuditNotesEdition comparison

CMS-HCC V28

HCC 153

Coefficient HCC 153: 0.396 (Community Non-Dual Aged (CNA))

CMS-HCC V24

Historical

Historical

Not used for CY2026 payment

ACA/HHS

Context needed

HCC 090

Coefficient needs member context

ESRD/PACE

Context needed

HCC 60

Coefficient needs member context

RXHCC

HCC 133

Code-level coefficient reference

Code Book Path

Official
F2Schizophrenia, schizotypal, delusional, and other non-mood psychotic disorders (F20-F29)F21Schizotypal disorder

Inclusion Terms

Official
  • Borderline schizophrenia
  • Latent schizophrenia
  • Latent schizophrenic reaction
  • Prepsychotic schizophrenia
  • Prodromal schizophrenia
  • Pseudoneurotic schizophrenia
  • Pseudopsychopathic schizophrenia
  • Schizotypal personality disorder

Excludes 2

Official
  • Asperger's syndrome (F84.5)
  • schizoid personality disorder (F60.1)
  • symptoms, signs and abnormal clinical laboratory findings, not elsewhere classified (R00-R99)Inherited from F01-F99

Related Codes

Official

No related codes are included in this display for F21. Check the Code Book for the complete code path.

Includes

Official
  • disorders of psychological developmentInherited from F01-F99

Excludes 1

Official

No Excludes 1 notes are included in this display for F21. Check the code and parent instructions in the Code Book.

Code First

Official

No Code First sequencing instructions are included in this display for F21. Check the code and parent instructions in the Code Book.

Use Additional

Official

No Use Additional Code instructions are included in this display for F21. Check the code and parent instructions in the Code Book.

Code Also

Official

No Code Also instructions are included in this display for F21. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance
Documented diagnosis by a qualified mental health professional
Description of characteristic features (odd beliefs, magical thinking, ideas of reference, unusual perceptual experiences, eccentric behavior, social anxiety)
Assessment confirming absence of full psychotic episodes (which would suggest schizophrenia)
Documentation that the pattern is pervasive and longstanding (personality disorder criteria)

MEAT Support

HCC Buddy guidance
Documented diagnosis by a qualified mental health professional
Description of characteristic features (odd beliefs, magical thinking, ideas of reference, unusual perceptual experiences, eccentric behavior, social anxiety)
Assessment confirming absence of full psychotic episodes (which would suggest schizophrenia)
Documentation that the pattern is pervasive and longstanding (personality disorder criteria)

Audit Caution

HCC Buddy guidance
Confusing schizotypal disorder with schizoid personality disorder — schizotypal has odd beliefs and perceptual disturbances that schizoid lacks
Coding schizophrenia when the patient has schizotypal features but has never had a full psychotic episode
Not recognizing that schizotypal disorder is on the schizophrenia spectrum and carries significant clinical weight
Using personality disorder NOS codes when the specific schizotypal presentation is documented

Common Mistakes

HCC Buddy guidance
F20.0 — Paranoid schizophrenia involves full psychotic episodes with delusions; schizotypal disorder does not
F60.1 — Schizoid personality disorder shares social withdrawal but lacks the odd beliefs and perceptual experiences of schizotypal disorder
F20.5 — Residual schizophrenia has a history of psychotic episodes; schizotypal disorder does not
F84.0 — Autism spectrum disorder may share social deficits but has different core features

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 F21 an HCC code?

Yes. F21 (Schizotypal disorder) maps to HCC 153, Personality Disorders; Anorexia/Bulimia Nervosa under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 0.396. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes. It is billable for payment year 2026.

Coder answer: F21 is billable and maps to V28 HCC 153, Personality Disorders; Anorexia/Bulimia Nervosa. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code
F21
Description
Schizotypal disorder
HCC (V28)
HCC 153 — Personality Disorders; Anorexia/Bulimia Nervosa
RAF reference coefficient
0.396
Billable
Yes
Payment year
2026

HCC Category Mapping

V28HCC 153, Personality Disorders; Anorexia/Bulimia Nervosa
0.396
RxHCCHCC 133, Anxiety and Other Psychiatric Disorders
Not separately weighted

These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. 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 context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.

Work F21 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for F21

For F21, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.

  • 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

Coder workflow notes

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What This Code Means

F21 is the ICD-10-CM diagnosis code for schizotypal disorder. A personality disorder characterized by odd beliefs, unusual perceptual experiences, and eccentric behavior, but without the full psychotic symptoms seen in schizophrenia. F21 sits in the ICD-10-CM chapter for mental, behavioral and neurodevelopmental disorders (f01-f99), within the section covering schizophrenia, schizotypal, delusional, and other non-mood psychotic disorders (f20-f29).

Under the CMS-HCC V28 risk adjustment model, F21 maps to Personality Disorders; Anorexia/Bulimia Nervosa (HCC 153) with a source-labeled community, non-dual, aged reference coefficient of 0.396. For CY2026 non-PACE Medicare Advantage, CMS uses 100% of the 2024 CMS-HCC model (V28). PACE uses a separate model blend. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes.

Distinguish from schizophrenia by confirming the absence of full psychotic episodes. For F21, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.

HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for F21 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

  • •Distinguish from schizophrenia by confirming the absence of full psychotic episodes
  • •Document the presence of magical thinking, ideas of reference, or unusual perceptions

Clinical Significance

Schizotypal disorder is a personality disorder characterized by eccentric behavior, odd beliefs (magical thinking), unusual perceptual experiences, and social deficits without the full psychotic symptoms of schizophrenia. It is classified within the schizophrenia spectrum and represents a lifelong pattern of cognitive and interpersonal deficits. The condition requires ongoing mental health treatment and has significant implications for patient functioning and quality of life.

Documentation Requirements

  • ✓Documented diagnosis by a qualified mental health professional
  • ✓Description of characteristic features (odd beliefs, magical thinking, ideas of reference, unusual perceptual experiences, eccentric behavior, social anxiety)
  • ✓Assessment confirming absence of full psychotic episodes (which would suggest schizophrenia)
  • ✓Documentation that the pattern is pervasive and longstanding (personality disorder criteria)
  • ✓Current functional assessment and treatment plan
  • ✓Differentiation from schizophrenia, avoidant personality disorder, and autism spectrum disorders

Excludes 2, Not included here, may code separately

  • Asperger's syndrome (F84.5)
  • schizoid personality disorder (F60.1)

Commonly Confused Codes

  • •F20.0: Paranoid schizophrenia involves full psychotic episodes with delusions; schizotypal disorder does not
  • •F60.1: Schizoid personality disorder shares social withdrawal but lacks the odd beliefs and perceptual experiences of schizotypal disorder
  • •F20.5: Residual schizophrenia has a history of psychotic episodes; schizotypal disorder does not
  • •F84.0: Autism spectrum disorder may share social deficits but has different core features
  • •F60.0: Paranoid personality disorder involves distrust without the perceptual oddities of schizotypal disorder

Code Hierarchy

└F21Schizotypal disorder
└F21Schizotypal disorder

For F21, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.

F21 maps to CMS-HCC V28 category 153, Personality Disorders; Anorexia/Bulimia Nervosa. See the ICD-10 to HCC mapping hub for how the V28 crosswalk works. The mapping identifies a payment HCC category for F21. Review its source-labeled HCC coefficient above, check the RAF Calculator with complete member context for CMS-HCC V28 PY2026, and confirm the documentation the chart needs before the code is submitted. HCC Buddy shows no RAF score unless every required source and calculation check passes.

Work F21 in HCC Buddy

Open F21 in the Code Book for the full Index-to-Tabular path, MEAT checklist, and V28 HCC mapping, or in the Encoder to code from a keyword search. Pro includes 7 days to try everything, no card required.

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