2027 ICD-10-CM Diagnosis Code Q07.9Congenital malformation of nervous system, unspecified
ICD-10-CM Codes›Q00-Q99›Q00-Q07›Q07
- Billable — Valid for Submission
- Risk Adjusts — HCC 182
- POA Exempt
- Chronic Condition
Q07.9 is a billable ICD-10-CM diagnosis code for congenital malformation of nervous system, unspecified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 91 through 93, 791, 793. The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nervous system congenital anomalies.
For Medicare Advantage risk adjustment, Q07.9 maps to CMS-HCC Category 182 (Spinal Cord Disorders/Injuries) under the V28 model, adding a risk factor of about 0.478 for a community, non-dual, aged beneficiary in payment year 2027.
Code Identity
Code Classification
Present on Admission (POA)Billing
Q07.9 is exempt from POA reporting on inpatient claims to general acute care hospitals. Review the other POA exempt codes in Congenital malformations of the nervous system (Q00-Q07).
Medicare Risk Adjustment (HCC)Billing
Q07.9 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.
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.
- Cerebrofacial dysplasia
- Coenzyme Q10 deficiency
- Combined malformation of central nervous system and skeletal muscle
- Congenital anomaly of central nervous system
- Congenital anomaly of nervous system
- Congenital anomaly of nervous system of head/neck
- Congenital anomaly of neural structure of trunk
- Congenital anomaly of peripheral nerve
- Congenital anomaly of the peripheral nervous system
- Congenital hepatic fibrosis
- Congenital malformation of autonomic nervous system
- Congenital malformation of the meninges
- Congenital polyneuropathy
- Cortical dysgenesis with pontocerebellar hypoplasia due to TUBB3 mutation
- Crome syndrome
- Cyprus facial neuromusculoskeletal syndrome
- Ectodermal dysplasia, intellectual disability, central nervous system malformation syndrome
- Encephalopathy, hypertrophic cardiomyopathy, renal tubular disease syndrome
- FBLN1-related developmental delay, central nervous system anomaly, syndactyly syndrome
- Global developmental delay, neuro-ophthalmological abnormalities, seizures, intellectual disability syndrome
- HIVEP2-related intellectual disability
- Hypertrophic mitochondrial cardiomyopathy
- Hypoplasia of optic nerve due to central nervous system malformation
- Immature autonomic system
- Male emopamil-binding protein disorder with neurological defect
- Muscle eye brain disease
- Muscle-eye-brain disease, congenital muscular dystrophy
- Navajo neurohepatopathy
- Neural tube defect
- Neurofaciodigitorenal syndrome
- NPHP3-related Meckel-like syndrome
- Pili torti
- Pili torti with developmental delay and neurological abnormality syndrome
- SCALP syndrome
- Sebaceous nevus
- Vascular malformation of the nervous system
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to Q07.9: its own notes plus those printed at Q07 and Chapter 17. A note printed at a category, block or chapter applies to every code under it.
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.
- Congenital anomaly NOS of nervous system
- Congenital deformity NOS of nervous system
- Congenital disease or lesion NOS of nervous system
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.
Notes
General instructions on how these codes are used.
- Codes from this chapter are not for use on maternal records
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name Q07.9, its category, or a range that includes it.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Abnormal, abnormality, abnormalities See Also: Anomaly;
Anomaly, anomalous (congenital) (unspecified type) Q89.9
gyri Q07.9
meningeal bands or folds Q07.9
meninges Q07.9
nerve Q07.9
nervous system (central) Q07.9
spinal See: Dorsopathy, deforming;
nerve root (congenital) Q07.9
Disease, diseased See Also: Syndrome;
congenital Q07.9
Maldevelopment See Also: Anomaly;
brain Q07.9
Malformation (congenital) See Also: Anomaly;
dura Q07.9
nervous system (central) Q07.9
sense organs NEC Q07.9
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Brain Malformations
Most brain malformations begin long before a baby is born. Something damages the developing nervous system or causes it to develop abnormally. Sometimes it's a genetic problem. In other cases, exposure to certain medicines, infections, or radiation during pregnancy interferes with brain development.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert Q07.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About Q07.9Overview
What is the ICD-10 code for congenital malformation of nervous system, unspecified?
The ICD-10-CM code for congenital malformation of nervous system, unspecified is Q07.9 (sometimes written as Q079). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is Q07.9 (Other congenital malformations of nervous system) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report congenital malformation of nervous system, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does Q07.9 group to?
When congenital malformation of nervous system, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 793, 791, 91, 92, 93, with relative weights from 0.7783 to 4.2192 depending on complications. Higher weights mean higher Medicare reimbursement.
Is Q07.9 exempt from POA reporting?
Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for congenital malformation of nervous system, unspecified on inpatient claims. The code appears in the Congenital malformations of the nervous system (Q00-Q07) range of the CMS exempt list.
What is the ICD-9 equivalent of Q07.9?
Under the General Equivalence Mappings, congenital malformation of nervous system, unspecified converts to ICD-9-CM 742.9 (nervous system anom NOS). The mapping is approximate, so confirm the match fits the documentation.
What HCC is Q07.9?
Q07.9 (congenital malformation of nervous system, unspecified) maps to CMS-HCC Category 182 (Spinal Cord Disorders/Injuries), commonly written as HCC 182, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 72 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 155.
Does Q07.9 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, Q07.9 adds a risk adjustment factor of about 0.478 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.270 to 0.478 depending on the payment segment). A more severe related category (HCC 180, HCC 181, HCC 191, and HCC 192) supersedes it when both are reported. See the full factor table on the HCC 182 category page.
