2027 ICD-10-CM Diagnosis Code O02.81Inappropriate change in quantitative human chorionic gonadotropin (hCG) in early pregnancy

ICD-10-CM Codes›O00-O9A›O00-O08›O02

ICD-10-CM O02.81
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

O02.81 is a billable ICD-10-CM diagnosis code for inappropriate change in quantitative human chorionic gonadotropin (hCG) in early pregnancy. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) 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 abnormal hormone secretion. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Molar pregnancy and other abnormal products of conception.

Code Identity

ICD-10-CM Code
O02.81
Billable Status
Yes — Valid for Submission
Code Describes
Inappropriate change in quantitative human chorionic gonadotropin (hCG) in early pregnancy
Short Description
Inapprop chg quantitav hCG in early pregnancy
Parent Code
O02.8
Other specified abnormal products of conception

Code Classification

ChapterO00-O9APregnancy, childbirth and the puerperium
SectionO00-O08Pregnancy with abortive outcome
CategoryO02Other abnormal products of conception
This CodeO02.81Inappropriate change in quantitative human chorionic gonadotropin (hCG) in early pregnancy

Code EditsBilling

Medicare Code Editor checks that affect claim validity for O02.81.

Maternity diagnoses
The Medicare Code Editor detects inconsistencies in maternity cases by checking a patient's age and any diagnosis on the patient's record. The maternity code edits apply to patients age ange is 9–64 years inclusive (e.g., diabetes in pregnancy, antepartum pulmonary complication).

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Abnormal hormone secretion
  • Abnormal placental secretion of chorionic gonadotropin
  • Absence of placental secretion of chorionic gonadotropin
  • Biochemical pregnancy
  • Finding related to placental secretion of chorionic gonadotropin

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to O02.81: its own notes plus those printed at O02.8, O02, block O00-O08, and Chapter 15. A note printed at a category, block or chapter applies to every code under it.

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • Biochemical pregnancy
  • Chemical pregnancy
  • Inappropriate level of quantitative human chorionic gonadotropin (hCG) for gestational age in early pregnancy

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From O02.8 Other specified abnormal products of conception applies to 2 codes
  • abnormal products of conception with blighted ovum (O02.0)
  • abnormal products of conception with hydatidiform mole (O01.-)
  • abnormal products of conception with nonhydatidiform mole (O02.0)
From O02 Other abnormal products of conception applies to 5 codes
From Block O00-O08 Pregnancy with abortive outcome applies to 110 codes
  • continuing pregnancy in multiple gestation after abortion of one fetus or more (O31.1-, O31.3-)
From Chapter 15 (O00-O9A) Pregnancy, childbirth and the puerperium applies to 2,481 codes
  • supervision of normal pregnancy (Z34.-)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 15 (O00-O9A) Pregnancy, childbirth and the puerperium applies to 2,481 codes
  • 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 Code

Add a second code, after this one, to fully describe the condition.

From O02 Other abnormal products of conception applies to 5 codes
  • code from category O08 to identify any associated complication.
From Chapter 15 (O00-O9A) Pregnancy, childbirth and the puerperium applies to 2,481 codes
  • code, if applicable, from category Z3A, Weeks of gestation, to identify the specific week of the pregnancy, if known.

Notes

General instructions on how these codes are used.

From Chapter 15 (O00-O9A) Pregnancy, childbirth and the puerperium applies to 2,481 codes
  • 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

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name O02.81, its category, or a range that includes it.

Applicable To 1

These notes mention O02.81.

  • O08 Complications following ectopic and molar pregnancy
    This category is for use with categories O00-O02 to identify any associated complications names O00-O02, which includes this code

Excludes1 12

These codes carry an Excludes1 note naming O02.81: they are not reported together with it, unless the two conditions are unrelated.

  • O02.1 Missed abortion
    missed abortion with other abnormal products of conception (O02.8-) names O02.8-, which includes this code
  • G08 Intracranial and intraspinal phlebitis and thrombophlebitis
    abortion, ectopic or molar pregnancy (O00-O07, O08.7) names O00-O07, which includes this code
  • K65 Peritonitis
    peritonitis with or following abortion or ectopic or molar pregnancy (O00-O07, O08.0) names O00-O07, which includes this code
  • Block N70-N77 Inflammatory diseases of female pelvic organs
    abortion or ectopic or molar pregnancy (O00-O07, O08.0) names O00-O07, which includes this code
  • R34 Anuria and oliguria
    anuria and oliguria complicating abortion or ectopic or molar pregnancy (O00-O07, O08.4) names O00-O07, which includes this code
  • R55 Syncope and collapse
    shock complicating or following abortion or ectopic or molar pregnancy (O00-O07, O08.3) names O00-O07, which includes this code
  • R57 Shock, not elsewhere classified
    shock complicating or following ectopic or molar pregnancy (O00-O07, O08.3) names O00-O07, which includes this code
  • T79.0 Air embolism (traumatic)
    air embolism complicating abortion or ectopic or molar pregnancy (O00-O07, O08.2) names O00-O07, which includes this code
  • T79.1 Fat embolism (traumatic)
    abortion or ectopic or molar pregnancy (O00-O07, O08.2) names O00-O07, which includes this code
  • T79.4 Traumatic shock
    shock complicating abortion or ectopic or molar pregnancy (O00-O07, O08.3) names O00-O07, which includes this code
  • T81.1 Postprocedural shock
    shock following abortion or ectopic or molar pregnancy (O00-O07, O08.3) names O00-O07, which includes this code
  • T81.7 Vascular complications following a procedure, not elsewhere classified
    embolism complicating abortion or ectopic or molar pregnancy (O00-O07, O08.2) names O00-O07, which includes this code

Excludes2 6

These codes carry an Excludes2 note naming O02.81: its condition is not part of those codes, and both may be reported when the patient has both.

  • D65 Disseminated intravascular coagulation [defibrination syndrome]
    abortion or ectopic or molar pregnancy (O00-O07, O08.1) names O00-O07, which includes this code
  • D68 Other coagulation defects
    coagulation defects complicating abortion or ectopic or molar pregnancy (O00-O07, O08.1) names O00-O07, which includes this code
  • I26 Pulmonary embolism
    pulmonary embolism complicating abortion, ectopic or molar pregnancy (O00-O07, O08.2) names O00-O07, which includes this code
  • K72 Hepatic failure, not elsewhere classified
    hepatic failure complicating abortion or ectopic or molar pregnancy (O00-O07, O08.8) names O00-O07, which includes this code
  • Block N17-N19 Acute kidney failure and chronic kidney disease
    renal failure complicating abortion or ectopic or molar pregnancy (O00-O07, O08.4) names O00-O07, which includes this code
  • Block N30-N39 Other diseases of the urinary system
    abortion or ectopic or molar pregnancy (O00-O07, O08.8) names O00-O07, which includes this code

Code First 6

These codes say to code first a condition named in the note, and O02.81 is one of the conditions named.

  • I47 Paroxysmal tachycardia
    abortion or ectopic or molar pregnancy (O00-O07, O08.8) names O00-O07, which includes this code
  • I49 Other cardiac arrhythmias
    abortion or ectopic or molar pregnancy (O00-O07, O08.8) names O00-O07, which includes this code
  • I50 Heart failure
    heart failure complicating abortion or ectopic or molar pregnancy (O00-O07, O08.8) names O00-O07, which includes this code
  • I74 Arterial embolism and thrombosis
    embolism and thrombosis complicating abortion or ectopic or molar pregnancy (O00-O07, O08.2) names O00-O07, which includes this code
  • I80 Phlebitis and thrombophlebitis
    if applicable: phlebitis and thrombophlebitis complicating abortion, ectopic or molar pregnancy (O00-O07, O08.7) names O00-O07, which includes this code
  • I82 Other venous embolism and thrombosis
    abortion, ectopic or molar pregnancy (O00-O07, O08.7) names O00-O07, which includes this code

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR PRG006
Molar pregnancy and other abnormal products of conception
Default principal diagnosis: inpatient Yes · outpatient Yes

Convert O02.81 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
631.0 Inapp chg hCG early preg
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About O02.81Overview

Is O02.81 (Other specified abnormal products of conception) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report inappropriate change in quantitative human chorionic gonadotropin (hCG) in early pregnancy on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does O02.81 group to?

When inappropriate change in quantitative human chorionic gonadotropin (hCG) in early pregnancy is the principal diagnosis on an inpatient stay, it groups to MS-DRG 833, 832, 831, 819, 818, 817, with relative weights from 0.5000 to 1.7586 depending on complications. Higher weights mean higher Medicare reimbursement.

Who can O02.81 be reported for?

The Medicare Code Editor checks inappropriate change in quantitative human chorionic gonadotropin (hCG) in early pregnancy against patient demographics: this code is intended for maternity cases (age 9 through 64). Claims outside these limits are flagged as inconsistent.

Can O02.81 be reported with O02.0?

Not as a rule. The Excludes1 note at O02.8, which applies to O02.81, lists "abnormal products of conception with blighted ovum (O02.0)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

Does O02.81 need an additional code?

When the condition applies, yes. The Use Additional Code note at O02, which applies to O02.81, reads: code from category O08 to identify any associated complication.. The additional code is reported after O02.81.