Z33.1Pregnant state, incidental

Z33.1 is the ICD-10-CM diagnosis code for Pregnant state, incidental. It belongs to category Z33 (Pregnant state), block Z30-Z39 (persons encountering health services in circumstances related to reproduction) and chapter 21 (factors influencing health status and contact with health services). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within Z33 (Pregnant state), Z33.1 is specifically for Pregnant state, incidental. Related codes cover encounter for elective termination of pregnancy (Z33.2) and gestational carrier (Z33.3).

Don't report Z33.1 together with the conditions in its Excludes1 note: complications of pregnancy (O00-O9A) and pregnant state, gestational carrier (Z33.3).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 951 (Other Factors Influencing Health Status, relative weight 0.5577), in MDC 23 (Factors Influencing Health Status and Other Contacts with Health Services), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

The Medicare Code Editor treats this as a maternity diagnosis, expected only for patients age 9 through 64.

It is not acceptable as the principal diagnosis for an inpatient stay; it may be reported as a secondary diagnosis.

It is on the CMS list of diagnoses consistent only with female patients (the sex-conflict edit itself was retired in FY2025).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as V22.2 (Pregnant state, incidental).