Coding and coverage · ICD-10-CM

O99 › O99.3

O99.35 Diseases of the nervous system complicating pregnancy, childbirth, and the puerperium

Not billable (header)Chapter 15

Report one of the more specific codes below.

Check coverage with this diagnosis

Codes under this one

  • O99.350 Diseases of the nervous system complicating pregnancy, unspecified trimester
  • O99.351 Diseases of the nervous system complicating pregnancy, first trimester
  • O99.352 Diseases of the nervous system complicating pregnancy, second trimester
  • O99.353 Diseases of the nervous system complicating pregnancy, third trimester
  • O99.354 Diseases of the nervous system complicating childbirth
  • O99.355 Diseases of the nervous system complicating the puerperium

Instructional notes

Chapter 15

Excludes1Not coded here: never report with this code, except when the two conditions are unrelated.
  • supervision of normal pregnancy (Z34.-)
Excludes2Not included here: the patient may have both; report both when both are present.
  • mental and behavioral disorders associated with the puerperium (F53.-)
  • obstetrical tetanus (A34)
  • postpartum necrosis of pituitary gland (E23.0)
  • puerperal osteomalacia (M83.0)
Use additional codeAdd a second code for the full picture.
  • code, if applicable, from category Z3A, Weeks of gestation, to identify the specific week of the pregnancy, if known.
Notes
  • CODES FROM THIS CHAPTER ARE FOR USE ONLY ON MATERNAL RECORDS, NEVER ON NEWBORN RECORDS
  • Codes from this chapter are for use for conditions related to or aggravated by the pregnancy, childbirth, or by the puerperium (maternal causes or obstetric causes)
  • Trimesters are counted from the first day of the last menstrual period. They are defined as follows:
  • 1st trimester- less than 14 weeks 0 days
  • 2nd trimester- 14 weeks 0 days to less than 28 weeks 0 days
  • 3rd trimester- 28 weeks 0 days until delivery

O99

Excludes2Not included here: the patient may have both; report both when both are present.
  • when the reason for maternal care is that the condition is known or suspected to have affected the fetus (O35-O36)
Use additional codeAdd a second code for the full picture.
  • code to identify specific condition
Includes
  • conditions which complicate the pregnant state, are aggravated by the pregnancy or are a main reason for obstetric care

This code

Excludes2Not included here: the patient may have both; report both when both are present.
  • pregnancy related peripheral neuritis (O26.8-)
Inclusion terms

Chapter 15: Pregnancy, childbirth and the puerperium (O00-O9A) · O94-O9A Other obstetric conditions, not elsewhere classified (O94-O9A)

Source: ICD-10-CM FY 2027 code descriptions and tabular list (CMS and CDC National Center for Health Statistics), effective 2026-10-01 through 2027-09-30 · CMS ICD-10 files. HCC mapping: CMS-HCC V28, payment year 2027. As of 2026-11-04.

Coverage and payment depend on the claim details; confirm with the Medicare Administrative Contractor.