ICD-10-CM 2026 · Effective October 1, 2025

ICD-10 R40.4

Billable / Specific

Transient alteration of awareness

R40
Block
0
Synonyms
346
LCDs
23
Payer Policies
0
Linked CPTs

About ICD-10-CM R40.4

ICD-10-CM code R40.4 represents Transient alteration of awareness. This is a billable/specific code in the Symptoms, Signs, and Abnormal Findings chapter (block R40). The 2026 edition of ICD-10-CM R40.4 became effective on October 1, 2025.

Medicare LCD Coverage for R40.4

Local Coverage Determinations (LCDs) from CMS MACs that list R40.4 as a covered diagnosis.

346 LCDs

Showing top 10 of 346 total . Click a CPT for full coverage scope.

CMS LCD: Billing and Coding: Ambulatory Electrocardiograph (AECG) Monitoring
Article ID: 59270, Effective: 2025-01-01 00:00:00, 153 covered, 0 non-covered
CPT 93270 →
CMS LCD: Billing and Coding: Ambulatory Electrocardiograph (AECG) Monitoring
Article ID: 59270, Effective: 2025-01-01 00:00:00, 153 covered, 0 non-covered
CPT 93298 →
CMS LCD: Billing and Coding: Ambulatory Electrocardiograph (AECG) Monitoring
Article ID: 59270, Effective: 2025-01-01 00:00:00, 153 covered, 0 non-covered
CPT 93225 →
CMS LCD: Billing and Coding: Ambulatory Electrocardiograph (AECG) Monitoring
Article ID: 59270, Effective: 2025-01-01 00:00:00, 153 covered, 0 non-covered
CPT 93271 →
CMS LCD: Billing and Coding: Ambulatory Electrocardiograph (AECG) Monitoring
Article ID: 59270, Effective: 2025-01-01 00:00:00, 153 covered, 0 non-covered
CPT 93246 →
CMS LCD: Billing and Coding: Ambulatory Electrocardiograph (AECG) Monitoring
Article ID: 59270, Effective: 2025-01-01 00:00:00, 153 covered, 0 non-covered
CPT 93272 →
CMS LCD: Billing and Coding: Ambulatory Electrocardiograph (AECG) Monitoring
Article ID: 59270, Effective: 2025-01-01 00:00:00, 153 covered, 0 non-covered
CPT 93242 →
CMS LCD: Billing and Coding: Ambulatory Electrocardiograph (AECG) Monitoring
Article ID: 59270, Effective: 2025-01-01 00:00:00, 153 covered, 0 non-covered
CPT 93228 →
CMS LCD: Billing and Coding: Ambulatory Electrocardiograph (AECG) Monitoring
Article ID: 59270, Effective: 2025-01-01 00:00:00, 153 covered, 0 non-covered
CPT 0938T →
CMS LCD: Billing and Coding: Ambulatory Electrocardiograph (AECG) Monitoring
Article ID: 59270, Effective: 2025-01-01 00:00:00, 153 covered, 0 non-covered
CPT 0937T →

Commercial Payer Coverage

Coverage policies from major commercial payers referencing R40.4.

23 policies

1 Cigna

Duplex Scan of Extracranial Arteries - (0542)
Policy ID: MM_0542

5 Medicare

Billing and Coding: Transesophageal Echocardiography (TEE)
Policy ID: ART-56505
Billing and Coding: CT of the Head
Policy ID: ART-56612
Billing and Coding: Nerve Conduction Studies and Electromyography
Policy ID: ART-56619
Billing and Coding: Echocardiography
Policy ID: ART-56625
Billing and Coding: Special Electroencephalography
Policy ID: ART-56771

1 Aetna

Transcranial Doppler Ultrasonography
Policy ID: CPB-0353

CPT Codes Commonly Billed with R40.4

Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.

No procedure linkages on file for R40.4

We don't have CPT pairings indexed for this specific code yet. Use the CPT search above to find common procedures, or check your payer's published medical policy for code-specific guidance.

Convert R40.4 to ICD-9-CM

Per CMS General Equivalence Mappings (GEMs), useful for legacy data review and historical claim analysis.

ICD-10ICD-9Mapping Flags
R40.4 78002 00000

Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).

ICD-10 R40.4, Billing FAQ

Is ICD-10 code R40.4 billable? +

Yes, R40.4 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.

What ICD-9 codes does R40.4 map to? +

Per CMS GEMs, R40.4 maps to ICD-9 codes: 78002. Useful for legacy data review and historical claim analysis.

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Reviewed by the PayerReady Medical Coding Team

Verified against the CMS 2026 code set on May 31, 2026.

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