O99.304 ICD-10-CA code: Mental disorders and diseases of the nervous system complicating pregnancy, childbirth and the puerperium, postpartum condition or complication
O99.304 is the ICD-10-CA code for “Mental disorders and diseases of the nervous system complicating pregnancy, childbirth and the puerperium, postpartum condition or complication” in CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026.
Official description
O99.304Mental disorders and diseases of the nervous system complicating pregnancy, childbirth and the puerperium, postpartum condition or complication
Short description: Ment disrd nerv sys preg birth/postpart
ICD-10-CA · Canada · Also written O99304
Notes for O99.304
As CIHI prints them, with any note O99.304 takes from the headings above it.
Includes
- • Conditions in F00-F52, F54-F99 and G00-G99From O99.3 Mental disorders and diseases of the nervous system complicating pregnancy, childbirth and the puerperium
Use additional code
Add a code for this detail when the note documents it.
- Use additional code to identify specific condition.From O99 Other maternal diseases classifiable elsewhere but complicating pregnancy, childbirth and the puerperium
Excludes
Conditions classified elsewhere.
- • cerebral venous sinus thrombosis in pregnancy (O22.5-)• cerebral venous sinus thrombosis in the puerperium (O87.3-)• postnatal depression (F53.0)• pregnancy-related peripheral neuritis (O26.8-)• puerperal psychosis (F53.1)From O99.3 Mental disorders and diseases of the nervous system complicating pregnancy, childbirth and the puerperium
- Infectious and parasitic diseases (O98.-)injury, poisoning and certain other consequences of external causes (S00-T98)when the reason for maternal care is that the condition is known or suspected to have affected the fetus (O35-O36)From O99 Other maternal diseases classifiable elsewhere but complicating pregnancy, childbirth and the puerperium
- Certain diseases or injuries complicating pregnancy, childbirth, and the puerperium classified elsewhere:external causes (for mortality) (V,W,X,Y)injury, poisoning and certain other consequences of external causes (S00-T88.1, T88.6-T98)mental and behavioural disorders associated with the puerperium (F53.-)obstetrical tetanus (A34)postpartum necrosis of pituitary gland (E23.0)puerperal osteomalacia (M83.0)supervision of:• high-risk pregnancy (Z35.-)• normal pregnancy (Z34.-)From Chapter 15: Pregnancy, childbirth and the puerperium (O00-O99)
Note
- This category includes conditions which complicate the pregnant state, are aggravated by the pregnancy or are a main reason for obstetric care and for which the Alphabetical Index does not indicate a specific rubric in Chapter XV.From O99 Other maternal diseases classifiable elsewhere but complicating pregnancy, childbirth and the puerperium
- For use of categories O95-O97 reference should be made to the mortality coding rules and guidelines.From O94-O99 Other obstetric conditions, not elsewhere classified
- The codes included in this chapter are to be used for conditions related to or aggravated by the pregnancy, childbirth or by the puerperium (maternal causes or obstetric causes)From Chapter 15: Pregnancy, childbirth and the puerperium (O00-O99)
Where O99.304 sits
- 1ChapterChapter 15: Pregnancy, childbirth and the puerperium (O00-O99)
- 2Block O94-O99Other obstetric conditions, not elsewhere classified
- 3Category O99Other maternal diseases classifiable elsewhere but complicating pregnancy, childbirth and the puerperium
- 4Subcategory O99.3Mental disorders and diseases of the nervous system complicating pregnancy, childbirth and the puerperium
- 5Valid code O99.304Mental disorders and diseases of the nervous system complicating pregnancy, childbirth and the puerperium, postpartum condition or complication
Source and release
- Data release
- ICD-10-CA · FY 2026–2027
- Effective date
- Apr 1, 2026
- Publisher
- CIHI
This page is built from the ICD-10-CA catalog that Vero Codes reads when it suggests codes: Canadian Institute for Health Information’s FY 2026–2027 release, imported from the publisher’s file and checked against it. The description, notes and structured data come from the same record.
Frequently asked questions
What does ICD-10-CA code O99.304 mean?
O99.304 is the ICD-10-CA code for “Mental disorders and diseases of the nervous system complicating pregnancy, childbirth and the puerperium, postpartum condition or complication” in CIHI’s ICD-10-CA FY 2026–2027 release.
Where is O99.304 in ICD-10-CA?
O99.304 sits under O99.3 Mental disorders and diseases of the nervous system complicating pregnancy, childbirth and the puerperium, within O99 Other maternal diseases classifiable elsewhere but complicating pregnancy, childbirth and the puerperium, within O94-O99 Other obstetric conditions, not elsewhere classified, within Chapter 15: Pregnancy, childbirth and the puerperium (O00-O99).
What coding notes apply to O99.304?
ICD-10-CA lists Includes, Excludes, Note, Use additional code notes for O99.304, including those from the headings it sits under. They are listed on this page with where each one comes from.
Which ICD-10-CA release does this page use?
It uses CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026 to Mar 31, 2027. It is a reference: confirm the code against the current list and the payer’s rules before you submit it.
Codes beside O99.304
View O99.3O99.301Mental disorders and diseases of the nervous system complicating pregnancy, childbirth and the puerperium, delivered, with or without mention of antepartum conditionO99.302Mental disorders and diseases of the nervous system complicating pregnancy, childbirth and the puerperium, delivered, with mention of postpartum complicationO99.303Mental disorders and diseases of the nervous system complicating pregnancy, childbirth and the puerperium, antepartum condition or complicationO99.309Mental disorders and diseases of the nervous system complicating pregnancy, childbirth and the puerperium, unspecified as to episode of care, or not applicable