2027 ICD-10-CM Diagnosis Code F44.9Dissociative and conversion disorder, unspecified
ICD-10-CM Codes›F01–F99›F40-F48›F44
- Billable — Valid for Submission
- Not Chronic
F44.9 is a billable ICD-10-CM diagnosis code for dissociative and conversion disorder, unspecified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 880. Coders also document this condition as acute hysterical psychosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Trauma- and stressor-related disorders.
F44.9 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 133 for payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
F44.9 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model, but it maps to payment categories in the other CMS models shown below.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Acute hysterical psychosis
- Conversion disorder, single episode
- Dissociation - mental defense mechanism
- Dissociative disorder
- Dissociative disorder in remission
- Dissociative neurological symptom disorder co-occurrent with chorea
- Dissociative neurological symptom disorder co-occurrent with myoclonus
- Recurrent conversion disorder
- Secondary dissociative disorder
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to F44.9: its own notes plus those printed at F44 and Chapter 5. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- conversion hysteria
- conversion reaction
- hysteria
- hysterical psychosis
- disorders of psychological development
Applicable To
Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.
- Dissociative disorder NOS
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- malingering [conscious simulation] (Z76.5)
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name F44.9, its category, or a range that includes it.
Excludes1 1
These codes carry an Excludes1 note naming F44.9: they are not reported together with it, unless the two conditions are unrelated.
Excludes2 2
These codes carry an Excludes2 note naming F44.9: its condition is not part of those codes, and both may be reported when the patient has both.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
hysterical F44.9
Disorder (of) See Also: Disease;
dissociative F44.9
conversion F44.9
hysterical F44.9
Psychoneurosis, psychoneurotic See Also: Neurosis;
hysteria F44.9
Reaction See Also: Disorder;
conversion F44.9
dissociative F44.9
hysterical F44.9
dissociative F44.9
Substitution disorder F44.9
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Conversion Disorder
a disorder whose predominant feature is a loss or alteration in physical functioning that suggests a physical disorder but that is actually a direct expression of a psychological conflict or need.Dissociative Disorders
sudden temporary alterations in the normally integrative functions of consciousness.Hysteria
historical term for a chronic, but fluctuating, disorder beginning in early life and characterized by recurrent and multiple somatic complaints not apparently due to physical illness. this diagnosis is not used in contemporary practice.
Patient EducationClinical
Mental Disorders
Mental disorders (or mental illnesses) are conditions that affect your thinking, feeling, mood, and behavior. They may happen over a short period of time or come and go. Some can be chronic (long-lasting). They can affect your ability to relate to others and function each day..
The full article covers:
- What are mental disorders?
- What are some types of mental disorders?
- What causes mental disorders?
- Who is at risk for mental disorders?
- How are mental disorders diagnosed?
- What are the treatments for mental disorders?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert F44.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About F44.9Overview
What is the ICD-10 code for dissociative and conversion disorder, unspecified?
The ICD-10-CM code for dissociative and conversion disorder, unspecified is F44.9 (sometimes written as F449). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is F44.9 (Dissociative and conversion disorders) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report dissociative and conversion disorder, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does F44.9 group to?
When dissociative and conversion disorder, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 880 (acute Adjustment Reaction and Psychosocial Dysfunction), which carries a relative weight of 0.9306. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of F44.9?
Under the General Equivalence Mappings, dissociative and conversion disorder, unspecified converts to ICD-9-CM 300.15 (dissociative react NOS). The mapping is approximate, so confirm the match fits the documentation.
Does F44.9 risk-adjust for Medicare Advantage payment?
Not for Medicare Advantage: F44.9 maps to no category in the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 133 (Anxiety and Other Psychiatric Disorders).
