O26.851 Spotting complicating pregnancy, first trimester

Billable ICD-10-CM code, FY2026.

MS-DRG index

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

Approximate ICD-9-CM (GEMs)

• 649.51 Spotting complicating pregnancy, delivered, with or without mention of antepartum condition (approximate)
• 649.53 Spotting complicating pregnancy, 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 O26.851

Back-references to O26.8

• Type 2 Excludes: O99.35 Diseases of the nervous system complicating pregnancy, childbirth, and the puerperium ("pregnancy related peripheral neuritis (O26.8-)")
• Type 1 Excludes: R53.8 Other malaise and fatigue ("exhaustion and fatigue due to pregnancy (O26.8-)")

Back-references to O26

• Type 1 Excludes: Z03.7 Encounter for suspected maternal and fetal conditions ruled out ("known or suspected fetal anomalies affecting management of mother, not ruled out (O26.-, O35.-, O36.-, O40.-, O41.-)")

Nearby codes

• O26.841 Uterine size-date discrepancy, first trimester
• O26.842 Uterine size-date discrepancy, second trimester
• O26.843 Uterine size-date discrepancy, third trimester
• O26.849 Uterine size-date discrepancy, unspecified trimester
• O26.85 Spotting complicating pregnancy
• O26.851 Spotting complicating pregnancy, first trimester (this code)
• O26.852 Spotting complicating pregnancy, second trimester
• O26.853 Spotting complicating pregnancy, third trimester
• O26.859 Spotting complicating pregnancy, unspecified trimester
• O26.86 Pruritic urticarial papules and plaques of pregnancy (PUPPP)
• O26.87 Cervical shortening