OB/GYN billing has run on the same bundled framework for decades: one CPT code covering antepartum care, delivery, and postpartum care as a single global package. That framework is being dismantled.
Effective January 1, 2027, the AMA CPT Editorial Panel’s restructuring of the global obstetric codes takes effect — replacing much of the current bundled structure with a more granular, itemized coding model. ACOG recommends practices begin transitioning no later than September 1, 2026. If your practice bills any global maternity codes, this transition needs to be on your radar now, not in December.
This guide covers the current global OB package rules for 2026, the denial trends practices are already seeing, and exactly what to do to prepare for the 2027 changeover.
OB/GYN Billing
The global obstetric package that’s defined maternity billing for decades is being restructured January 1, 2027. ACOG recommends transitioning antepartum billing by September 1, 2026.
ACOG recommends billing antepartum visits with standard E/M codes (99202–99499) + modifier TH starting no later than 9/1/2026 — before the global codes 59425/59426 are deleted January 1, 2027. Patients spanning both years need this transition now.
Part 1: The Global Obstetric Package — How It Works Today
The Global Obstetrical Package bundles routine antepartum care, delivery, and postpartum care into a single reimbursement for uncomplicated pregnancies.
The four primary global codes:
| Code | Description |
|---|---|
| 59400 | Vaginal delivery — global package (antepartum + delivery + postpartum) |
| 59510 | Cesarean delivery — global package |
| 59610 | VBAC — global package |
| 59618 | Attempted VBAC converting to cesarean — global package |
What’s included in the global package:
- Approximately 13 routine antepartum visits (monthly through 28 weeks, biweekly through 36 weeks, weekly from 36 weeks to delivery)
- Initial and subsequent history and physical exams
- Routine weight, blood pressure, fundal height, and fetal heart tone monitoring
- Admission history and physical, labor management, and the delivery itself
- Postpartum hospital visits plus the standard ~6-week postpartum office visit
What’s excluded and separately billable:
- Medically necessary ultrasounds beyond routine prenatal monitoring
- Laboratory tests
- Unrelated medical services (e.g., a patient presenting with flu during a prenatal visit — bill separately with the appropriate E/M code)
- Long-acting reversible contraception provided at or near delivery
- Surgical complications, billed separately with appropriate documentation
⚠️ CMS explicitly exempted the four global maternity codes from the 2026 RVU efficiency reduction — the fee schedule protection is holding for 2026. But payer-level claim edits on the components underneath the global rate are increasing regardless, which is where most of this year’s denial growth is actually happening.
Part 2: When to Split the Global Package
The global package must be split — rather than billed as a single bundled code — in several common scenarios:
- Care transferred mid-pregnancy — the referring provider bills antepartum-only codes (59425 for 4–6 visits, 59426 for 7+ visits), and the delivering provider bills the delivery code plus any antepartum visits they personally provided
- Fewer than 13 antepartum visits by a single physician — use the partial antepartum codes rather than forcing a global claim
- Delivery-only scenarios — use 59409 (vaginal) or 59514 (cesarean) when another provider managed antepartum care
- Postpartum-only care — use 59430 when a different provider handled the delivery
Do not report antepartum E/M visit codes alongside the corresponding global or partial antepartum code — this double-counts the same encounter and is a common cause of payer audit flags.
Part 3: Where OB/GYN Denials Are Actually Coming From in 2026
The 2026 RVU exemption protects the allowable rate for global maternity codes — it does nothing to protect what your practice actually collects. Payer-level claim edits targeting the documentation underneath the global package are driving denial growth this year:
Pattern 1 — Incomplete transfer-of-care documentation: A global claim submitted without itemizing antepartum visits performed by a prior provider gets downcoded by the payer to the partial antepartum code — a real revenue loss per delivery when this happens.
Pattern 2 — Co-management modifier omission: When an attending OB and a maternal-fetal medicine specialist share care, missing Modifier 54/55 splits (surgical care only / postoperative care only) causes payer confusion about who is billing what.
Pattern 3 — VBAC conversion documentation gaps: CPT 59618 carries one of the highest denial rates in the maternity category. Without explicit documentation of the conversion from attempted VBAC to cesarean, payers reclassify the claim to 59510 at a lower contracted rate — a difference that can run into the hundreds of dollars per delivery.
Pattern 4 — Modifier 25 overlap: Medicare Advantage plans are applying algorithmic claim review to maternity codes at meaningfully higher rates than just a few years ago, specifically flagging Modifier 25 claims where the E/M documentation shares language with a same-day procedure note.
Part 4: The 2027 Transition — What’s Changing and What to Do Now
The AMA CPT Editorial Panel has approved a full restructuring of the 16 global OB codes, replacing them with a new granular code set (in the 59XX1–59X12 range) effective January 1, 2027. The change addresses a long-standing complaint from OB/GYN providers: the global package treats an uncomplicated pregnancy and a pregnancy with extensive antepartum complications identically, despite vastly different clinical effort.
Key transition guidance from ACOG:
- Begin billing antepartum visits using standard E/M codes (99202–99499) rather than global antepartum codes, starting no later than September 1, 2026 — this ensures a smoother transition for patients whose pregnancies span the 2026–2027 boundary
- Append HCPCS modifier TH to E/M codes used for maternity-related visits, to help payers distinguish maternity E/M encounters from standard E/M visits
- For OB coding purposes only, ACOG recommends treating pregnancy as “one or more chronic illnesses with exacerbation, progression, or side effects of treatment” when selecting E/M complexity level — since “pregnancy” itself is not classified as a problem in standard E/M frameworks
- Codes 59425 and 59426 (partial antepartum codes) remain available through 2026 but will be deleted in 2027
Practical timeline for your practice:
| Milestone | Timing |
|---|---|
| Begin using E/M + modifier TH for antepartum visits | No later than September 1, 2026 |
| Test TH modifier acceptance with top payers | Q4 2026 |
| New restructured codes take effect | January 1, 2027 |
| Global codes 59425/59426 deleted | January 1, 2027 |
⚠️ Why this matters right now: A patient who begins antepartum care in late 2026 and delivers in 2027 will fall across both coding systems. Practices that wait until January 2027 to adjust their workflow risk weeks of claim rejections during the exact period when patient volume doesn’t pause for a coding transition.
Part 5: Documentation Priorities for 2026
Beyond the 2027 transition, a few documentation habits meaningfully reduce denial exposure this year:
- Always report the weeks-of-gestation code (Z3A.xx) as a secondary diagnosis on every obstetric claim
- Use laterality and specificity on pelvic pain diagnoses — the 2026 ICD-10 update requires this, and unspecified codes (like R10.2) increase medical necessity denial risk
- Document Modifier 22 use with an operative report clearly describing why a delivery required substantially more work than typical — adhesions or other significant intraoperative findings
- Code an uncomplicated delivery as O80 (normal delivery) even if the antepartum period carried a high-risk designation — the high-risk supervision code does not automatically carry over to an uncomplicated delivery
What OB/GYN Practices Should Do Right Now
For 2026 billing:
- Audit your last 20 global maternity claims for complete antepartum visit documentation before submission, not after a denial
- Confirm Modifier 54/55 usage is correct on every co-managed pregnancy involving MFM referral
- Require explicit VBAC-to-cesarean conversion language in operative notes to protect CPT 59618 reimbursement
For the 2027 transition:
- Start transitioning antepartum billing to E/M codes with modifier TH no later than September 1, 2026
- Test modifier TH claim acceptance with your top 3–5 payers in Q4 2026, before volume ramps into January
- Train front-desk and billing staff now — this is a workflow change, not just a code change
For denial prevention broadly:
- Treat global maternity denials as a revenue integrity issue, not a standard denial management issue — the documentation gaps causing today’s denials often can’t be recreated retroactively once the visit record is incomplete
Final Thoughts
2026 is a bridge year for OB/GYN billing. The current global package structure holds for now, protected from the broader RVU efficiency cuts — but the documentation standards underneath it are tightening, and the entire coding framework changes in January 2027. Practices that treat this as a Q3 2026 project, testing new workflows well before the deadline, will avoid the claim rejection wave that’s likely to hit practices still running 2026 habits into a 2027 coding world.
At ClaimsXperts, we help OB/GYN practices navigate global maternity billing, co-management modifier structures, and the upcoming 2027 CPT transition — building revenue cycle workflows around what payers actually require, not what worked last year.
Contact us today at https://www.rcmmasters.com/#contactus to learn how ClaimsXperts can support your OB/GYN practice through this transition.
ClaimsXperts is a Revenue Cycle Management company based in Frisco, TX, serving medical practices across the United States. We specialize in medical billing, coding, and insurance credentialing for solo practitioners, group practices, and specialty clinics.
