O99
Other maternal diseases classifiable elsewhere but complicating pregnancy, childbirth and the puerperium
Not billable — category only FY2026 2025-10-01 → 2026-09-30
Exclusions 6 never code together
Instructional notes 9
O99code
Includes
- conditions which complicate the pregnant state, are aggravated by the pregnancy or are a main reason for obstetric care
Use additional code
- code to identify specific condition
O00-O9Achapter
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
Use additional code
- code, if applicable, from category Z3A, Weeks of gestation, to identify the specific week of the pregnancy, if known.Z3A
Index entries leading here filed at null
No alphabetic index entry points at this code.
Subordinate codes 9
O99.0 Anemia complicating pregnancy, childbirth and the puerperium O99.1 Other dis blood/immune compl preg/childbrth O99.2 Endo, nutritional and metabolic diseases compl preg/chldbrth O99.3 Mental disord and dis of the nervous sys compl preg/chldbrth O99.4 Diseases of the circulatory system compl preg/chldbrth O99.5 Diseases of the respiratory system compl preg/chldbrth O99.6 Diseases of the digestive system compl preg/chldbrth O99.7 Diseases of the skin, subcu compl preg/chldbrth O99.8 Oth diseases and conditions compl preg/chldbrth
Additional references
AHA Coding Clinic® Licence required
Official coding advice for this code. Published by the American Hospital Association. Not included in this installation.