O99.351 — Diseases of the nervous system complicating pregnancy, first trimester
Is O99.351 billable?
Yes — O99.351 is billable for FY2027. O99.351 is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. O99.351 may be submitted for encounters from October 1, 2026 through September 30, 2027.
O99.351 at a glance
| Code | O99.351 |
|---|---|
| Description | Diseases of the nervous system complicating pregnancy, first trimester |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does O99.351 group to?
O99.351 sits in MDC 14 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.
- 817Other Antepartum Diagnoses with O.R. Procedures with MCCsurgical
- 818Other Antepartum Diagnoses with O.R. Procedures with CCsurgical
- 819Other Antepartum Diagnoses with O.R. Procedures without CC/MCCsurgical
How is O99.351 listed in the Alphabetic Index?
The Alphabetic Index lists these routes under O99.35, the nearest indexed parent of O99.351. Use them to find the family, then select the specific code.
- Pregnancy › complicated by › nervous system condition (single) (uterine)
Excludes1 — never code together — inherited from Chapter 15
The conditions below can never be reported together with O99.351 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- supervision of normal pregnancy (Z34.-)
Use additional code — inherited from Chapter 15
Report an additional code alongside O99.351 to fully describe the condition. O99.351 is sequenced first.
- code, if applicable, from category Z3A, Weeks of gestation, to identify the specific week of the pregnancy, if known.
Use additional code — inherited from O99
Report an additional code alongside O99.351 to fully describe the condition. O99.351 is sequenced first.
- code to identify specific condition
Excludes2 — not included here — inherited from Chapter 15
The conditions below are not part of O99.351, but a patient may have both at the same time. When documentation supports it, O99.351 and the excluded code may both be reported.
Excludes2 — not included here — inherited from O99
The conditions below are not part of O99.351, but a patient may have both at the same time. When documentation supports it, O99.351 and the excluded code may both be reported.
- when the reason for maternal care is that the condition is known or suspected to have affected the fetus (O35-O36)
Excludes2 — not included here — inherited from O99.35
The conditions below are not part of O99.351, but a patient may have both at the same time. When documentation supports it, O99.351 and the excluded code may both be reported.
- pregnancy related peripheral neuritis (O26.8-)
How long has O99.351 existed?
O99.351 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.
What other codes are in the O99.35 family? (5)
- O99.350Diseases of the nervous system complicating pregnancy, unspecified trimester
- O99.352Diseases of the nervous system complicating pregnancy, second trimester
- O99.353Diseases of the nervous system complicating pregnancy, third trimester
- O99.354Diseases of the nervous system complicating childbirth
- O99.355Diseases of the nervous system complicating the puerperium