2026 ICD-10-CM Diagnosis Code O01.9Hydatidiform mole, unspecified
ICD-10-CM Codes›O00-O9A›O00-O08›O01
- Billable — Valid for Submission
- Not Chronic
O01.9 is a billable ICD-10-CM diagnosis code for hydatidiform mole, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 817 through 819, 831 through 833. The code is restricted by the Medicare Code Editor to maternity cases (age 9 through 64). Coders also document this condition as gestational trophoblastic disease. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Molar pregnancy and other abnormal products of conception.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for O01.9.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Gestational trophoblastic disease
- Hydatidiform mole, benign
- Hyperthyroidism due to hydatidiform mole with thyrotoxic crisis
- Hyperthyroidism due to molar thyrotropin
- Placental site nodule
- Residual trophoblastic disease
- Thyrotoxic crisis
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Trophoblastic disease NOS
- Vesicular mole NOS
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
- Mole (pigmented) - See Also: Nevus;
- Pregnancy (single) (uterine) - See Also: Delivery and Puerperal; - Z33.1
- complicated by (care of) (management affected by)
- hydatidiform mole - See Also: Mole, hydatidiform; - O01.9
- hydatidiform - See Also: Mole, hydatidiform; - O01.9
- Trophoblastic disease - See Also: Mole, hydatidiform; - O01.9
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Hydatidiform mole(benign) (complicating pregnancy) (delivered) (undelivered)
- Mole(pigmented)
- hydatid, hydatidiform (benign) (complicating pregnancy) (delivered) (undelivered)
- Pregnancy(single) (uterine)
- complicated by (care of) (management affected by)
- hydatidiform mole
- Pregnancy(single) (uterine)
- molar NEC
- hydatidiform
- Trophoblastic disease
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Hydatidiform Mole
trophoblastic hyperplasia associated with normal gestation, or molar pregnancy. it is characterized by the swelling of the chorionic villi and elevated human chorionic gonadotropin. hydatidiform moles or molar pregnancy may be categorized as complete or partial based on their gross morphology, histopathology, and karyotype.Hydatidiform Mole, Invasive
a uterine tumor derived from persistent gestational trophoblasts, most likely after a molar pregnancy (hydatidiform mole). invasive hyadatiform mole develops in about 15% of patients after evacuation of a complete mole and less frequently after other types of gestation. it may perforate the myometrium and erode uterine vessels causing hemorrhage.Gestational Trophoblastic Disease
a group of diseases arising from pregnancy that are commonly associated with hyperplasia of trophoblasts (trophoblast) and markedly elevated human chorionic gonadotropin. they include hydatidiform mole, invasive mole (hydatidiform mole, invasive), placental-site trophoblastic tumor (trophoblastic tumor, placental site), and choriocarcinoma. these neoplasms have varying propensities for invasion and spread.
Patient EducationClinical
Tumors and Pregnancy
Tumors during pregnancy are rare, but they can happen. Tumors can be either benign (not cancer) or malignant (cancer). The most common cancers in pregnancy include breast cancer, thyroid cancer, cervical cancer, lymphoma, and melanoma. Cancer itself rarely harms the fetus, and some cancer treatments are safe during pregnancy.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert O01.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About O01.9Overview
Is O01.9 (Hydatidiform mole) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report hydatidiform mole, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does O01.9 group to?
When hydatidiform mole, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 817, 818, 819, 831, 832, 833, with relative weights from 0.5229 to 1.6880 depending on complications. Higher weights mean higher Medicare reimbursement.
Who can O01.9 be reported for?
The Medicare Code Editor checks hydatidiform mole, unspecified against patient demographics: this code is intended for maternity cases (age 9 through 64). Claims outside these limits are flagged as inconsistent.
What is the ICD-9 equivalent of O01.9?
Under the General Equivalence Mappings, hydatidiform mole, unspecified converts to ICD-9-CM 630 (hydatidiform mole). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
