ICD-10-CM Tabular Index · Chapter 15 · FY 2026 O99

Other maternal diseases classifiable elsewhere but complicating pregnancy, childbirth and the puerperium (O99) ICD-10-CM

The O99 code range covers other maternal diseases classifiable elsewhere but complicating pregnancy, childbirth and the puerperium with 124 ICD-10-CM diagnosis codes. 96 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.

✓ Built from the official CMS FY 2026 datasetEffective Oct 1, 2025 – Sep 30, 2026
124
Diagnosis Codes
96
Billable Codes
O99
Code Range
O94–O9A
Parent Section

Includes

This note appears immediately under a three character code title to further define, or give examples of, the content of the category.

Use Additional Code

The “use additional code” indicates that a secondary code could be used to further specify the patient’s condition. This note is not mandatory and is only used if enough information is available to assign an additional code.

Type 2 Excludes

A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.

ICD-10-CM

Codes in the O99 Range 124 codes · 96 billable

124 of 124 shown
  • O99 Other maternal diseases classifiable elsewhere but complicating pregnancy, childbirth and the puerperiumNon-billable
  • O99.0 Anemia complicating pregnancy, childbirth and the puerperiumNon-billable
  • O99.01 Anemia complicating pregnancyNon-billable
  • O99.011 Anemia complicating pregnancy, first trimester
  • O99.012 Anemia complicating pregnancy, second trimester
  • O99.013 Anemia complicating pregnancy, third trimester
  • O99.019 Anemia complicating pregnancy, unspecified trimester
  • O99.02 Anemia complicating childbirth
  • O99.03 Anemia complicating the puerperium
  • O99.1 Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating pregnancy, childbirth and the puerperiumNon-billable
  • O99.11 Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating pregnancyNon-billable
  • O99.111 Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating pregnancy, first trimester
  • O99.112 Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating pregnancy, second trimester
  • O99.113 Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating pregnancy, third trimester
  • O99.119 Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating pregnancy, unspecified trimester
  • O99.12 Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating childbirth
  • O99.13 Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating the puerperium
  • O99.2 Endocrine, nutritional and metabolic diseases complicating pregnancy, childbirth and the puerperiumNon-billable
  • O99.21 Obesity complicating pregnancy, childbirth, and the puerperiumNon-billable
  • O99.210 Obesity complicating pregnancy, unspecified trimester
  • O99.211 Obesity complicating pregnancy, first trimester
  • O99.212 Obesity complicating pregnancy, second trimester
  • O99.213 Obesity complicating pregnancy, third trimester
  • O99.214 Obesity complicating childbirth
  • O99.215 Obesity complicating the puerperium
  • O99.28 Other endocrine, nutritional and metabolic diseases complicating pregnancy, childbirth and the puerperiumNon-billable
  • O99.280 Endocrine, nutritional and metabolic diseases complicating pregnancy, unspecified trimester
  • O99.281 Endocrine, nutritional and metabolic diseases complicating pregnancy, first trimester
  • O99.282 Endocrine, nutritional and metabolic diseases complicating pregnancy, second trimester
  • O99.283 Endocrine, nutritional and metabolic diseases complicating pregnancy, third trimester
  • O99.284 Endocrine, nutritional and metabolic diseases complicating childbirth
  • O99.285 Endocrine, nutritional and metabolic diseases complicating the puerperium
  • O99.3 Mental disorders and diseases of the nervous system complicating pregnancy, childbirth and the puerperiumNon-billable
  • O99.31 Alcohol use complicating pregnancy, childbirth, and the puerperiumNon-billable
  • O99.310 Alcohol use complicating pregnancy, unspecified trimester
  • O99.311 Alcohol use complicating pregnancy, first trimester
  • O99.312 Alcohol use complicating pregnancy, second trimester
  • O99.313 Alcohol use complicating pregnancy, third trimester
  • O99.314 Alcohol use complicating childbirth
  • O99.315 Alcohol use complicating the puerperium
  • O99.32 Drug use complicating pregnancy, childbirth, and the puerperiumNon-billable
  • O99.320 Drug use complicating pregnancy, unspecified trimester
  • O99.321 Drug use complicating pregnancy, first trimester
  • O99.322 Drug use complicating pregnancy, second trimester
  • O99.323 Drug use complicating pregnancy, third trimester
  • O99.324 Drug use complicating childbirth
  • O99.325 Drug use complicating the puerperium
  • O99.33 Tobacco use disorder complicating pregnancy, childbirth, and the puerperiumNon-billable
  • O99.330 Smoking (tobacco) complicating pregnancy, unspecified trimester
  • O99.331 Smoking (tobacco) complicating pregnancy, first trimester
  • O99.332 Smoking (tobacco) complicating pregnancy, second trimester
  • O99.333 Smoking (tobacco) complicating pregnancy, third trimester
  • O99.334 Smoking (tobacco) complicating childbirth
  • O99.335 Smoking (tobacco) complicating the puerperium
  • O99.34 Other mental disorders complicating pregnancy, childbirth, and the puerperiumNon-billable
  • O99.340 Other mental disorders complicating pregnancy, unspecified trimester
  • O99.341 Other mental disorders complicating pregnancy, first trimester
  • O99.342 Other mental disorders complicating pregnancy, second trimester
  • O99.343 Other mental disorders complicating pregnancy, third trimester
  • O99.344 Other mental disorders complicating childbirth
  • O99.345 Other mental disorders complicating the puerperium
  • O99.35 Diseases of the nervous system complicating pregnancy, childbirth, and the puerperiumNon-billable
  • 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
  • O99.4 Diseases of the circulatory system complicating pregnancy, childbirth and the puerperiumNon-billable
  • O99.41 Diseases of the circulatory system complicating pregnancyNon-billable
  • O99.411 Diseases of the circulatory system complicating pregnancy, first trimester
  • O99.412 Diseases of the circulatory system complicating pregnancy, second trimester
  • O99.413 Diseases of the circulatory system complicating pregnancy, third trimester
  • O99.419 Diseases of the circulatory system complicating pregnancy, unspecified trimester
  • O99.42 Diseases of the circulatory system complicating childbirth
  • O99.43 Diseases of the circulatory system complicating the puerperium
  • O99.5 Diseases of the respiratory system complicating pregnancy, childbirth and the puerperiumNon-billable
  • O99.51 Diseases of the respiratory system complicating pregnancyNon-billable
  • O99.511 Diseases of the respiratory system complicating pregnancy, first trimester
  • O99.512 Diseases of the respiratory system complicating pregnancy, second trimester
  • O99.513 Diseases of the respiratory system complicating pregnancy, third trimester
  • O99.519 Diseases of the respiratory system complicating pregnancy, unspecified trimester
  • O99.52 Diseases of the respiratory system complicating childbirth
  • O99.53 Diseases of the respiratory system complicating the puerperium
  • O99.6 Diseases of the digestive system complicating pregnancy, childbirth and the puerperiumNon-billable
  • O99.61 Diseases of the digestive system complicating pregnancyNon-billable
  • O99.611 Diseases of the digestive system complicating pregnancy, first trimester
  • O99.612 Diseases of the digestive system complicating pregnancy, second trimester
  • O99.613 Diseases of the digestive system complicating pregnancy, third trimester
  • O99.619 Diseases of the digestive system complicating pregnancy, unspecified trimester
  • O99.62 Diseases of the digestive system complicating childbirth
  • O99.63 Diseases of the digestive system complicating the puerperium
  • O99.7 Diseases of the skin and subcutaneous tissue complicating pregnancy, childbirth and the puerperiumNon-billable
  • O99.71 Diseases of the skin and subcutaneous tissue complicating pregnancyNon-billable
  • O99.711 Diseases of the skin and subcutaneous tissue complicating pregnancy, first trimester
  • O99.712 Diseases of the skin and subcutaneous tissue complicating pregnancy, second trimester
  • O99.713 Diseases of the skin and subcutaneous tissue complicating pregnancy, third trimester
  • O99.719 Diseases of the skin and subcutaneous tissue complicating pregnancy, unspecified trimester
  • O99.72 Diseases of the skin and subcutaneous tissue complicating childbirth
  • O99.73 Diseases of the skin and subcutaneous tissue complicating the puerperium
  • O99.8 Other specified diseases and conditions complicating pregnancy, childbirth and the puerperiumNon-billable
  • O99.81 Abnormal glucose complicating pregnancy, childbirth and the puerperiumNon-billable
  • O99.810 Abnormal glucose complicating pregnancy
  • O99.814 Abnormal glucose complicating childbirth
  • O99.815 Abnormal glucose complicating the puerperium
  • O99.82 Streptococcus B carrier state complicating pregnancy, childbirth and the puerperiumNon-billable
  • O99.820 Streptococcus B carrier state complicating pregnancy
  • O99.824 Streptococcus B carrier state complicating childbirth
  • O99.825 Streptococcus B carrier state complicating the puerperium
  • O99.83 Other infection carrier state complicating pregnancy, childbirth and the puerperiumNon-billable
  • O99.830 Other infection carrier state complicating pregnancy
  • O99.834 Other infection carrier state complicating childbirth
  • O99.835 Other infection carrier state complicating the puerperium
  • O99.84 Bariatric surgery status complicating pregnancy, childbirth and the puerperiumNon-billable
  • O99.840 Bariatric surgery status complicating pregnancy, unspecified trimester
  • O99.841 Bariatric surgery status complicating pregnancy, first trimester
  • O99.842 Bariatric surgery status complicating pregnancy, second trimester
  • O99.843 Bariatric surgery status complicating pregnancy, third trimester
  • O99.844 Bariatric surgery status complicating childbirth
  • O99.845 Bariatric surgery status complicating the puerperium
  • O99.89 Other specified diseases and conditions complicating pregnancy, childbirth and the puerperiumNon-billable
  • O99.891 Other specified diseases and conditions complicating pregnancy
  • O99.892 Other specified diseases and conditions complicating childbirth
  • O99.893 Other specified diseases and conditions complicating puerperium

Clinical Terms in This Code Range

Definitions from the National Library of Medicine for conditions coded in the O99 range.

Bicornuate Uterus

A congenital uterine anomaly in which the UTERUS is divided into two uterine horns with a significant cleft at the uterine fundus due to partial fusion of the MULLERIAN DUCTS. Bicornuate uterus is sometimes associated with a longitudinal vaginal septum and abnormal development of renal tracts.

Chorea Gravidarum

A rare movement disorder developed during PREGNANCY, characterized by involuntary jerky motion (CHOREA) and inability to maintain stable position of body parts (ATHETOSIS). RHEUMATIC FEVER and collagen vascular disorders are frequently associated with this disease. Chorea may vary from mild to severe and occurs in approximately 1 per 2,000 to 3,000 pregnancies. (From Md Med J 1997 Sep;46(8):436-9)

Hemoglobinuria

The presence of free HEMOGLOBIN in the URINE, indicating hemolysis of ERYTHROCYTES within the vascular system. After saturating the hemoglobin-binding proteins (HAPTOGLOBINS), free hemoglobin begins to appear in the urine.

Hemoglobinuria, Paroxysmal

A condition characterized by the recurrence of HEMOGLOBINURIA caused by intravascular HEMOLYSIS. In cases occurring upon cold exposure (paroxysmal cold hemoglobinuria), usually after infections, there is a circulating antibody which is also a cold hemolysin. In cases occurring during or after sleep (paroxysmal nocturnal hemoglobinuria), the clonal hematopoietic stem cells exhibit a global deficiency of cell membrane proteins.

Restless Legs Syndrome

A disorder characterized by aching or burning sensations in the lower and rarely the upper extremities that occur prior to sleep or may awaken the patient from sleep.

Sickle Cell Trait

The condition of being heterozygous for hemoglobin S.

About the O99 Code Range

The O99 ICD-10 codes cover a range of maternal diseases and conditions that are classified in other categories but specifically complicate pregnancy, childbirth, and the puerperium. These codes are used when a maternal illness from another system affects the mother's pregnancy or delivery experience.

The section includes specific codes for various conditions such as anemia (O99.0), blood and immune disorders (O99.1), endocrine and metabolic diseases like obesity (O99.2), mental and nervous system disorders (O99.3 and O99.35), circulatory (O99.4), respiratory (O99.5), digestive (O99.6), skin diseases (O99.7), and other specified conditions complicating maternal care. For example, anemia related to pregnancy (sometimes referred to as "nutritional anemia of pregnancy" or "iron deficiency anemia of pregnancy") is coded under O99.019 if the trimester is unspecified. Similarly, “Group B streptococcus carrier state” complicating pregnancy is classified under O99.820. These codes help healthcare providers and coders document how pre-existing or concurrent diseases impact maternal health during pregnancy, labor, or postpartum.

By distinguishing trimester and timing (pregnancy, childbirth, puerperium), these codes allow precise tracking of complications like drug use (O99.32), tobacco use (O99.33), mental disorders (O99.34), or abnormal glucose tolerance (O99.81) affecting maternal and fetal outcomes. This detailed coding enables targeted treatment planning and better clinical communication for complex maternal cases.

Questions About This Page

How many billable codes are in the O99 range?

Of the 124 codes in this range, 96 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.

What does the O99 range classify?

The range classifies other maternal diseases classifiable elsewhere but complicating pregnancy, childbirth and the puerperium. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.

Related References

All ICD-10-CM ChaptersAll of Chapter 15ICD-10-CM Code LookupMS-DRG ReferenceMedicare Code EditsPOA Exempt Codes

Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.