O60.02 Preterm labor without delivery, second trimester

Billable ICD-10-CM code, FY2026. Acts as a Major Complication or Comorbidity (MCC) as a secondary diagnosis.

Applies from O60 Preterm labor

Includes

• onset (spontaneous) of labor before 37 completed weeks of gestation

Excludes1 (never code together)

• false labor (O47.0-)
• threatened labor NOS (O47.0-)

MS-DRG index

Defines the logic of DRG(s) 817-819 in MDC 14.

Approximate ICD-9-CM (GEMs)

• 644.03 Threatened premature labor, antepartum condition or complication (approximate)

Medicare Code Edits (MCE v43.1 (April 2026))

• Maternity diagnoses (age 9 through 64): Age conflict edit. These diagnoses are clinically expected only in patients age 9 through 64.

Code annotations containing back-references to O60.02

Back-references to O60

• Type 1 Excludes: O47 False labor ("preterm labor (O60.-)")
• Code First: Z3A Weeks of gestation ("obstetric condition or encounter for delivery (O09-O60, O80-O82, O94-O9A)")

Diagnosis Index entries for O60.02

• Pregnancy (single) (uterine) › complicated by (care of) (management affected by) › preterm labor › second trimester › without delivery
• Pregnancy (single) (uterine) › complicated by (care of) (management affected by) › preterm labor › without delivery › second trimester

Nearby codes

• O60 Preterm labor
• O60.0 Preterm labor without delivery
• O60.00 Preterm labor without delivery, unspecified trimester
• O60.02 Preterm labor without delivery, second trimester (this code)
• O60.03 Preterm labor without delivery, third trimester
• O60.1 Preterm labor with preterm delivery
• O60.10 Preterm labor with preterm delivery, unspecified trimester
• O60.10X0 Preterm labor with preterm delivery, unspecified trimester, not applicable or unspecified
• O60.10X1 Preterm labor with preterm delivery, unspecified trimester, fetus 1