2027 ICD-10-CM Diagnosis Code O22.33Deep phlebothrombosis in pregnancy, third trimester
ICD-10-CM Codes›O00-O9A›O20-O29›O22
- Billable — Valid for Submission
- MCC — Major Complication or Comorbidity
- Not Chronic
O22.33 is a billable ICD-10-CM diagnosis code for deep phlebothrombosis in pregnancy, third trimester. 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. As a secondary diagnosis, it counts as a major complication or comorbidity (MCC) and places an inpatient stay in the highest severity level of its MS-DRG family. It does not count, however, when the principal diagnosis is one of 250 closely related codes. The code is restricted by the Medicare Code Editor to maternity cases (age 9 through 64). In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Acute phlebitis; thrombophlebitis and thromboembolism and Other specified complications in pregnancy.
This medical diagnosis code is frequently used in OB/GYN medical specialties to designate conditions such maternal disorders related to pregnancy.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for O22.33.
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to O22.33: its own notes plus those printed at O22.3, O22, block O20-O29, and Chapter 15. A note printed at a category, block or chapter applies to every code under it.
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
- 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.
Use Additional Code
Add a second code, after this one, to fully describe the condition.
- 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.
- 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 O22.33, its category, or a range that includes it.
Excludes2 2
These codes carry an Excludes2 note naming O22.33: its condition is not part of those codes, and both may be reported when the patient has both.
- O87 Venous complications and hemorrhoids in the puerperiumvenous complications in pregnancy (O22.-) names O22.-, which includes this code
- O99.4 Diseases of the circulatory system complicating pregnancy, childbirth and the puerperiumvenous complications and cerebrovenous sinus thrombosis in pregnancy (O22.-) names O22.-, which includes this code
Code First 2
These codes say to code first a condition named in the note, and O22.33 is one of the conditions named.
- I80 Phlebitis and thrombophlebitisphlebitis and thrombophlebitis complicating pregnancy, childbirth and the puerperium (O22.-, O87.-) names O22.-, which includes this code
- I82 Other venous embolism and thrombosispregnancy, childbirth and the puerperium (O22.-, O87.-) names O22.-, which includes this code
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Deep Vein Thrombosis
Deep vein thrombosis, or DVT, is a blood clot that forms in a vein deep in the body. Most deep vein clots occur in the lower leg or thigh. If the vein swells, the condition is called thrombophlebitis. A deep vein thrombosis can break loose and cause a serious problem in the lung, called a pulmonary embolism.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert O22.33 to ICD-9-CMHistory
Code HistoryHistory
Questions About O22.33Overview
What is the ICD-10 code for deep phlebothrombosis in pregnancy, third trimester?
The ICD-10-CM code for deep phlebothrombosis in pregnancy, third trimester is O22.33 (sometimes written as O2233). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is O22.33 (Deep phlebothrombosis in pregnancy) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report deep phlebothrombosis in pregnancy, third trimester on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does O22.33 group to?
When deep phlebothrombosis in pregnancy, third trimester 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.
Is O22.33 a CC or MCC?
CMS lists O22.33 as an MCC (major complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it places the inpatient stay in the highest-weighted DRG of its severity family. It does not count when the principal diagnosis is one of the 250 closely related codes in its exclusion list.
Who can O22.33 be reported for?
The Medicare Code Editor checks deep phlebothrombosis in pregnancy, third trimester against patient demographics: this code is intended for maternity cases (age 9 through 64). Claims outside these limits are flagged as inconsistent.
