F51.5 is the authoritative medical code for Nightmare disorder. This classification is used in medical billing and clinical recording to specify the clinical criteria for nightmare disorder (ICD-10-CM F51.5), ensuring healthcare documentation aligns with 2026 federal coding standards.
Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.
Official Registry Overview & Definition
Nightmare disorder is a billable ICD-10-CM diagnosis code F51.5. Inclusion terms: Dream anxiety disorder. Excludes2 (not included here): organic sleep disorders G47.-.
Official Tabular Instructional Notes
Sequencing, inclusion, and exclusion notes published for F51.5 in the official ICD-10-CM tabular list.
Inclusion Terms
Alternative terms the tabular list files under this code.
Excludes2 — Not Included Here
Conditions not covered by this code, but which may be reported alongside it when both are present.
- organic sleep disorders G47.-
Frequently Asked Questions (FAQ) & Clinical Guidance
Can F51.5 be reported alongside related conditions?
Per Excludes2 instructions, F51.5 and the following may both be reported when both are present: organic sleep disorders (G47.-).
What conditions are included under F51.5?
Nightmare disorder includes: Dream anxiety disorder.
Codes in This Family (17)
Official ICD-10-CM classifications in the same code family as F51.5, with their registry titles.
- F51 — Sleep disorders not due to a substance or known physiological condition
- F51.0 — Insomnia not due to a substance or known physiological condition
- F51.01 — Primary insomnia
- F51.02 — Adjustment insomnia
- F51.03 — Paradoxical insomnia
- F51.04 — Psychophysiologic insomnia
- F51.05 — Insomnia due to other mental disorder
- F51.09 — Other insomnia not due to a substance or known physiological condition
- F51.1 — Hypersomnia not due to a substance or known physiological condition
- F51.11 — Primary hypersomnia
- F51.12 — Insufficient sleep syndrome
- F51.13 — Hypersomnia due to other mental disorder
- F51.19 — Other hypersomnia not due to a substance or known physiological condition
- F51.3 — Sleepwalking [somnambulism]
- F51.4 — Sleep terrors [night terrors]
- F51.8 — Other sleep disorders not due to a substance or known physiological condition
- F51.9 — Sleep disorder not due to a substance or known physiological condition, unspecified
Indexed Clinical Terms (4)
Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code.
- Disorder (of), dream anxiety
- Disorder (of), nightmare
- Disorder (of), sleep, nightmares
- Nightmares (REM sleep type)
Related Codes & Numerical Sequence (Crawl Map)
Search engines and indexers are advised to traverse adjacent medical codes in this sub-chapter range to find correlated diagnoses or therapeutic procedures:
ICD Code F52.5
Vaginismus not due to a substance or known physiological condition