What is ICD-10 code F98.21?

F98.21 is the ICD-10-CM diagnosis code for Rumination disorder of infancy and childhood. A feeding disorder in infants and young children characterized by repeated regurgitation and rechewing of food that has already been swallowed, without nausea or gastrointestinal disease. F98.21 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. F98.21 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. F98.21 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. F98.21 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

What is the V28 vs V24 difference for F98.21?

F98.21 does not map to a payment HCC under either the CMS-HCC V28 risk adjustment model or the older V24 model. V28 reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition. Because neither model rewards F98.21 with a risk adjustment factor, it contributes zero to a Medicare Advantage beneficiary's RAF score in either version. Coders should check whether provider documentation supports a more specific child code that does map to a payment HCC.

What should coders know when reporting F98.21?

This diagnosis requires documentation that the behavior is not due to GERD, pyloric stenosis, or other medical conditions Typically diagnosed in children ages 3 months to 2 years; document the child's age and developmental context

F98.21: Rumination disorder of infancy and childhood — ICD-10

ICD-10-CM Code View

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Code lookupF98.21Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Mental, Behavioral and Neurodevelopmental disorders (F01-F99) / Behavioral and emotional disorders with onset usually occurring in childhood and adolescence (F90-F98)

F98.21

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

Rumination disorder of infancy and childhood

A feeding disorder in infants and young children characterized by repeated regurgitation and rechewing of food that has already been swallowed, without nausea or gastrointestinal disease.

Buddy Insight

Rumination disorder of infancy and childhood involves repeated regurgitation and re-chewing of food that is not attributable to gastrointestinal or other medical conditions.

CMS-HCC V28

Not risk-adjusted for this model/period.

RAF 0

CMS-HCC V24

Not risk-adjusted for this model/period.

RAF 0

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Not risk-adjusted for this model/period.

RAF 0

RXHCC

Mapped

HCC 133

Personality Disorders, Anxiet...

RAF 0.0

Code Trumping

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Code Book Path

Official

F98Other behavioral and emotional disorders with onset usually occurring in childhood and adolescence

F98.2Other feeding disorders of infancy and childhood

F98.21Rumination disorder of infancy and childhood

Inclusion Terms

Official

Rumination disorder in infancy or childhood, in remission

Excludes 2

Official

anorexia nervosa and other eating disorders (F50.-)
feeding difficulties (R63.3-)
feeding problems of newborn (P92.-)
pica of infancy or childhood (F98.3)

Related Child Codes

Official

F98.29Other feeding disorders of infancy and early childhood

Includes

Official

ICD-10-CM does not list Includes notes for F98.21 in this effective period.

Excludes 1

Official

rumination disorder in adults (F50.84)

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for F98.21 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for F98.21 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for F98.21 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Provider documentation of rumination disorder diagnosis

Evidence of repeated regurgitation of food over at least one month

Documentation that the behavior is not due to a gastrointestinal condition (e.g., GERD, pyloric stenosis)

Documentation that the behavior does not occur exclusively during an eating disorder (anorexia nervosa, bulimia)

MEAT Support

HCC Buddy guidance

Provider documentation of rumination disorder diagnosis

Evidence of repeated regurgitation of food over at least one month

Documentation that the behavior is not due to a gastrointestinal condition (e.g., GERD, pyloric stenosis)

Documentation that the behavior does not occur exclusively during an eating disorder (anorexia nervosa, bulimia)

Audit Caution

HCC Buddy guidance

Coding rumination disorder when the regurgitation is caused by a GI medical condition like GERD — must exclude medical causes first

Using the 'other feeding disorders' code F98.29 when rumination disorder is specifically documented

Not evaluating nutritional status and growth parameters when rumination disorder is identified

Coding rumination disorder when it occurs exclusively within the context of an eating disorder (anorexia, bulimia)

Common Mistakes

HCC Buddy guidance

K21.0 — GERD with esophagitis; GERD is a gastrointestinal medical condition, not a behavioral disorder

F98.29 — Other feeding disorders of infancy and early childhood; use F98.21 specifically for rumination

F50.x — Eating disorders; rumination occurring exclusively within anorexia or bulimia is coded to the eating disorder

P92.x — Feeding problems of newborn; neonatal feeding difficulties are coded separately from rumination disorder

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

Is F98.21 an HCC code?

No. F98.21 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.

HCC Category Mapping

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

0.000

RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. 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.

Work F98.21 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for F98.21

For F98.21to 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 F98.21 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

F98.21 is the ICD-10-CM diagnosis code for rumination disorder of infancy and childhood. A feeding disorder in infants and young children characterized by repeated regurgitation and rechewing of food that has already been swallowed, without nausea or gastrointestinal disease. F98.21 sits in the ICD-10-CM chapter for mental, behavioral and neurodevelopmental disorders (f01-f99), within the section covering behavioral and emotional disorders with onset usually occurring in childhood and adolescence (f90-f98).

F98.21 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.

F98.21 does not map to any HCC in V28 or V24 models. RxHCC maps to 133 (0.000). No risk adjustment impact. Clinical coding is essential for tracking nutritional consequences and behavioral treatment needs. Coders reviewing F98.21 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 F98.21 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•This diagnosis requires documentation that the behavior is not due to GERD, pyloric stenosis, or other medical conditions
•Typically diagnosed in children ages 3 months to 2 years; document the child's age and developmental context

Clinical Significance

Rumination disorder of infancy and childhood involves repeated regurgitation and re-chewing of food that is not attributable to gastrointestinal or other medical conditions. In infants, it can lead to failure to thrive, malnutrition, and death if untreated. In older children, it causes significant nutritional and dental complications. This behavioral feeding disorder requires multidisciplinary management including behavioral therapy and nutritional support.

Documentation Requirements

✓Provider documentation of rumination disorder diagnosis
✓Evidence of repeated regurgitation of food over at least one month
✓Documentation that the behavior is not due to a gastrointestinal condition (e.g., GERD, pyloric stenosis)
✓Documentation that the behavior does not occur exclusively during an eating disorder (anorexia nervosa, bulimia)
✓Nutritional assessment, growth parameters, and treatment plan including behavioral intervention

Excludes 1, Do NOT code together

rumination disorder in adults (F50.84)

Commonly Confused Codes

•K21.0: GERD with esophagitis; GERD is a gastrointestinal medical condition, not a behavioral disorder
•F98.29: Other feeding disorders of infancy and early childhood; use F98.21 specifically for rumination
•F50.x: Eating disorders; rumination occurring exclusively within anorexia or bulimia is coded to the eating disorder
•P92.x: Feeding problems of newborn; neonatal feeding difficulties are coded separately from rumination disorder

Child Codes

F98.21Rumination disorder of infancy and childhood

F98.29Other feeding disorders of infancy and early childhood

Code Hierarchy

└F98Other behavioral and emotional disorders with onset usually occurring in childhood and adolescence └F98.2Other feeding disorders of infancy and childhood └F98.21Rumination disorder of infancy and childhood

└F98.21Rumination disorder of infancy and childhood

F98.21 ICD-10-CM Code: Rumination disorder of infancy and childhood

HCC Buddy Code Card

F98.21

Is F98.21 an HCC code?

HCC Category Mapping

MEAT Criteria for F98.21

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What This Code Means

Coding Tips

Clinical Significance

Documentation Requirements

Excludes 1, Do NOT code together

Commonly Confused Codes

Child Codes

Code Hierarchy

Work F98.21 in HCC Buddy