F40.220 ICD-10-CM Code: Fear of thunderstorms
F40.220 is not a CMS-HCC payment code. MEAT criteria · RAF calculator · HCC coding software
HCC Buddy Code Card
Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.
FY 2026 Apr update / Mental, Behavioral and Neurodevelopmental disorders (F01-F99) / Anxiety, dissociative, stress-related, somatoform and other nonpsychotic mental disorders (F40-F48)
F40.220
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceFear of thunderstorms
An intense fear of thunderstorms that causes significant anxiety and avoidance of outdoor activities during storms.
Buddy Insight
Fear of thunderstorms (astraphobia) is a specific phobia in the natural environment subtype involving intense fear or anxiety related to thunderstorms, lightning, or severe weather events.
CMS-HCC V28
N/A—
Not mapped
CMS-HCC V24
N/A—
Not mapped
ACA/HHS
N/A—
Not mapped
ESRD/PACE
N/A—
Not mapped
RXHCC
MappedHCC 133
RAF 0.035
Code Book Path
Inclusion Terms
OfficialICD-10-CM does not list inclusion terms for F40.220 in this effective period.
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for F40.220 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for F40.220 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for F40.220 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for F40.220 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for F40.220 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for F40.220 in this effective period.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
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 F40.220 an HCC code?
F40.220 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
- F40.220
- Description
- Fear of thunderstorms
- HCC (V28)
- No CMS-HCC V28 mapping
- RAF
- —
- Billable
- Yes
- Payment year
- 2026
HCC Category Mapping
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.
Work F40.220 in the Code Book — tabular path, V28 RAF, and MEAT checklist →
MEAT Criteria for F40.220
For F40.220 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 F40.220 during that encounter, not just copy-forwarded from a problem list.
Coder workflow notes
Get the V28 RAF + MEAT cheat sheet
One printable page: confirm a code's V28 HCC status, its RAF weight, and the MEAT your note needs to make it stick. Free, no card.
Free PDF. No card. Unsubscribe anytime.
What This Code Means
F40.220 is the ICD-10-CM diagnosis code for fear of thunderstorms. An intense fear of thunderstorms that causes significant anxiety and avoidance of outdoor activities during storms. F40.220 sits in the ICD-10-CM chapter for mental, behavioral and neurodevelopmental disorders (f01-f99), within the section covering anxiety, dissociative, stress-related, somatoform and other nonpsychotic mental disorders (f40-f48).
F40.220 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 F40.220 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 F40.220 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This falls under natural environment type phobias
- •Document whether fear is of the storm itself, lightning, or loud noises associated with storms
Clinical Significance
Fear of thunderstorms (astraphobia) is a specific phobia in the natural environment subtype involving intense fear or anxiety related to thunderstorms, lightning, or severe weather events. This can be clinically significant when it leads to severe avoidance behaviors during storm seasons. It does not map to any HCC and is not risk-adjusting.
Documentation Requirements
- ✓Marked fear or anxiety specifically about thunderstorms or severe weather
- ✓Disproportionate fear response relative to actual danger
- ✓Consistent anxiety response triggered by storms or storm forecasts
- ✓Avoidance behaviors (e.g., refusing to leave shelter, excessive weather monitoring)
- ✓Duration of 6+ months
- ✓Clinically significant distress or functional impairment
Commonly Confused Codes
- •F40.228 (Other natural environment type phobia): Use F40.220 specifically for thunderstorm phobia; F40.228 covers other natural environment fears like water or darkness
- •F40.241 (Acrophobia): Fear of heights is a separate natural environment phobia with its own code
- •F41.1 (Generalized anxiety disorder): GAD involves chronic worry across many domains; astraphobia is situation-specific