ICD-10-CM · Mental, behavioral, neurodevelopmental
ICD-10-CM · Mental, behavioral, neurodevelopmentalF33.9: Major depressive disorder, recurrent, unspecified
F33.9 is the ICD-10-CM code for Major depressive disorder, recurrent, unspecified. Billable on U.S. claims with supporting documentation. Chapter: Mental, behavioral, neurodevelopmental. Category: F33.
About this code
Major depressive disorder, recurrent, unspecified.
F33.9 is an ICD-10-CM diagnosis code for major depressive disorder, recurrent, unspecified. It sits in the 5. Mental, behavioral, neurodevelopmental chapter of the U.S. clinical modification, under category F33.
This code is billable on U.S. healthcare claims when supported by appropriate clinical documentation. The patient chart must establish the diagnosis, capture any clinical detail encoded in the code (severity, laterality, encounter type, complications where applicable), and demonstrate medical necessity for the billed services.
Payer-specific coverage rules vary. Always cross-check against the current Local Coverage Determinations (LCDs) and National Coverage Determinations (NCDs) for the payer adjudicating the claim, plus any specialty-specific CMS Medicare Administrative Contractor guidance.
Billing context
What practitioners watch for on F33.9.
Chapter-level billing guidance for mental, behavioral, neurodevelopmental codes. Code-specific notes ship as the dataset matures.
Documentation
Document specific diagnosis per DSM-5/ICD-10 criteria, severity (mild, moderate, severe), episode (single, recurrent), and remission status. Behavioral health denials cluster around specificity and parity-law eligibility.
Common denial categories
- CO-16: Information missing or incorrect on the claim or in supporting documentation. Add documentation specificity that supports the coded detail; resubmit with corrected information.
- CO-50: Service not deemed medically necessary by the payer. Confirm the diagnosis-procedure relationship matches LCD/NCD coverage, attach clinical justification, appeal with documentation.
- CO-11: Diagnosis is inconsistent with the procedure performed. Verify the diagnosis-to-procedure pairing per payer policy; correct the linked diagnosis pointer or the procedure code.
Coverage signal
Mental health parity laws (MHPAEA) require commercial plans to cover behavioral health on terms no more restrictive than medical/surgical benefits. Prior auth is common for IOP, PHP, and inpatient levels of care.
Common specialties
Mental Health & Psychiatry · Behavioral Health
Companion CPT codes
Procedures commonly billed alongside F33.9 based on Medonix client production data and CMS coding guidance.
- 90791Psychiatric diagnostic evaluation
- 90834Psychotherapy, 45 minutes
- 90837Psychotherapy, 60 minutes
- 99213Office visit, established (medical management)
- 90833Psychotherapy 30 min add-on with E/M
CPT is a registered trademark of the American Medical Association. Codes shown for educational reference only.
Related codes
Other codes in category F33.
- F33.0
Major depressive disorder, recurrent, mild
Open - F33.1
Major depressive disorder, recurrent, moderate
Open - F33.2
Major depressive disorder, recurrent severe without psychotic features
Open - F33.3
Major depressive disorder, recurrent, severe with psychotic symptoms
Open - F33.40
Major depressive disorder, recurrent, in remission, unspecified
Open - F33.41
Major depressive disorder, recurrent, in partial remission
Open - F33.42
Major depressive disorder, recurrent, in full remission
Open - F33.8
Other recurrent depressive disorders
Open
Sources
Where this entry comes from.
- NLM Clinical Tables Search Service: the official U.S. National Library of Medicine API for ICD-10-CM lookup.
- CDC National Center for Health Statistics: annual ICD-10-CM Tabular List release with effective date October 1.
- CMS Medicare Coverage Database: Local Coverage Determinations and National Coverage Determinations for payer-specific rules.
Frequently asked
About ICD-10 code F33.9.
Talk to RCM
Ready to recover every dollar your practice earns?
See your projected revenue lift in 60 seconds, or talk to a senior RCM strategist now. No commitment. Same-day slots available.
- 30-day parallel-run guarantee
- Targets written into the contract
- HIPAA · SOC 2 Type II · HITRUST