OB-GYN Billing Denials: Where Practices Lose Revenue (and How to Stop It)

Initial denial rates rose again in 2025, to an average of 11.6% (Kodiak Solutions), with prior-authorization and medical-necessity denials accounting for most of the increase. OB-GYN is exposed because so much of its revenue runs through global packages, preventive-plus-problem visits and bundled imaging, all places where a small coding choice decides whether the claim pays.

1. Global maternity billed when care was split

CPT 59400, 59510, 59610 and 59618 assume one practice managed the pregnancy from the first prenatal visit through the postpartum visit. When care transfers, a patient moves practices mid-pregnancy, or delivers with a different group, the global code is wrong for everyone involved. Antepartum-only care uses 59425 (4-6 visits) or 59426 (7+); delivery-only and postpartum-only (59430) codes exist for a reason. Billing the full global code when you only saw part of the pregnancy denies almost every time, because the payer sees overlapping claims.

2. Modifier 25 on well-woman plus problem visits

A preventive well-woman exam and a separately identifiable problem addressed the same day are both billable, but only with modifier 25 on the problem-focused E/M and documentation that clearly separates the two services. Without it, the E/M bundles into the preventive visit and that revenue is gone.

3. Ultrasounds and labs folded into the global fee

Obstetric ultrasounds, glucose tolerance testing and diagnostic workup outside routine prenatal monitoring are never part of the global maternity fee. They are billed separately regardless of how routine the pregnancy is. Folding them into 59400 to "keep it simple" just leaves that revenue unbilled.

4. Global surgical periods (modifiers 24, 58, 78, 79)

Laparoscopy, hysterectomy, LEEP and other gynecologic procedures carry global periods. An office visit or a second procedure inside that window needs the right modifier, 24 for an unrelated visit, 58 for a staged procedure, 78 for a related return to the OR, 79 for an unrelated one, or it bundles.

5. Prior authorization

Advanced imaging, infertility workups, some surgical procedures and certain drugs are gated behind prior authorization for most commercial plans. In the AMA's 2025 survey, 95% of physicians said prior authorization delays necessary care. For OB-GYN the practical cost is a service delivered but not billable clean until the authorization is documented.

How a dedicated RCM partner reduces them

A billing partner scrubs each claim against payer-specific rules before submission, so global-package, modifier-25 and separately-billable-service issues are caught while they can still be fixed. Authorization is tracked as its own workflow step. Denials are root-caused by category and payer, and the fix is written back into the scrub rules so the same denial doesn't repeat. AR is worked by recovery probability rather than oldest-first. It all happens inside your existing EHR and clearinghouse. Our OB-GYN billing page covers the specialty workflow in more detail.

Sources

Kodiak Solutions, 2025 Revenue Cycle Benchmarking analysis, kodiaksolutions.com.
American Medical Association, 2025 Prior Authorization Physician Survey, ama-assn.org.
American College of Obstetricians and Gynecologists (ACOG) coding resources, acog.org.
Centers for Medicare & Medicaid Services, Physician Fee Schedule and NCCI Policy Manual, cms.gov.