Q28.1 — Other malformations of precerebral vessels
Is Q28.1 billable?
Yes — Q28.1 is billable for FY2027. Q28.1 is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. Q28.1 may be submitted for encounters from October 1, 2026 through September 30, 2027.
Q28.1 at a glance
| Code | Q28.1 |
|---|---|
| Description | Other malformations of precerebral vessels |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does Q28.1 group to?
Q28.1 sits in MDC 05 and helps define the logic of 3 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 299Peripheral Vascular Disorders with MCCmedical
- 300Peripheral Vascular Disorders with CCmedical
- 301Peripheral Vascular Disorders without CC/MCCmedical
As a secondary diagnosis, Q28.1 is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.
How is Q28.1 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to Q28.1. They show the wording a clinician may have documented, which often differs from the Tabular description.
- Anomaly, anomalous › precerebral vessel (congenital) (unspecified type)
- Dissection › precerebral artery, congenital
- Distribution vessel, atypical › precerebral
- Malformation › precerebral vessels (congenital)
- Aberrant › artery › basilar NEC (congenital)
- Aberrant › artery › precerebral (congenital)
- Aberrant › artery › vertebral (congenital)
- Aberrant › veinNEC › precerebral (congenital)
- Absence › veincongenital NEC › precerebral (of) (organ or part) (complete or partial)
- Aneurysm › precerebral › congenital (anastomotic) (artery) (cirsoid) (diffuse) (false) (fusiform) (multiple) (saccular)
- Anomaly, anomalous › artery › basilar NEC (congenital) (unspecified type)
- Anomaly, anomalous › artery › vertebral NEC (congenital) (unspecified type)
Inclusion terms
Alternative wording in documentation that is classified to Q28.1.
- Congenital malformation of precerebral vessels NOS
- Congenital precerebral aneurysm (nonruptured)
Excludes1 — never code together — inherited from Q28
The conditions below can never be reported together with Q28.1 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
Excludes2 — not included here — inherited from Chapter 17
The conditions below are not part of Q28.1, but a patient may have both at the same time. When documentation supports it, Q28.1 and the excluded code may both be reported.
- inborn errors of metabolism (E70-E88)
Excludes2 — not included here — inherited from Q28
The conditions below are not part of Q28.1, but a patient may have both at the same time. When documentation supports it, Q28.1 and the excluded code may both be reported.
How long has Q28.1 existed?
Q28.1 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.