The Global OB Package Ends in 2027: What OB/GYN Practices Must Do

What is changing with global OB billing in 2027?

As of August 2026, the global obstetric package, the bundled CPT codes 59400, 59510, 59610, and 59618 that have covered maternity care since the 1990s, is scheduled for deletion on January 1, 2027. In its place, maternity care will be reported in four separate phases: antepartum, labor management, delivery, and postpartum. CMS has also proposed competing G-codes that would keep the old bundled structure for Medicare, which is where the confusion starts.

What replaces it. Antepartum and postpartum care shift to E/M codes, while new stand-alone codes report the labor management and delivery phases.

The CMS wrinkle. The July 2026 proposed rule floats 15 new HCPCS G-codes that preserve bundling, which ACOG warns creates a confusing dual billing system.

What to do now. ACOG advises starting the E/M transition for antepartum visits by September 1, 2026, using modifier TH to flag maternity care.

What Changed in Obstetric Coding

For more than 30 years, maternity care has been billed with the global obstetric package: one bundled code covering antepartum visits, delivery, and postpartum care. The four global codes are 59400 for a vaginal delivery, 59510 for a cesarean, 59610 for a vaginal birth after cesarean, and 59618 for a cesarean after attempted VBAC. Effective January 1, 2027, the AMA is deleting those global codes and replacing them with phase-specific reporting.

The AMA CPT Editorial Panel approved the change to reflect modern, team-based obstetric care, where multiple unaffiliated providers often deliver different phases of a pregnancy. According to the AMA’s CPT 2027 maternity update, the restructuring deletes 17 codes, adds 12, and revises 6 in this subsection of the code set. The four phases of maternity care, antepartum, labor management, delivery, and postpartum, are each reported separately from January 1, 2027.

The mechanics matter for every OB practice. Antepartum and postpartum visits move to standard evaluation and management (E/M) codes, while new codes report labor management and the delivery itself. The antepartum-only codes 59425 and 59426, along with the delivery-and-care globals, are being retired in the same transition. This is the largest change to maternity billing in a generation.

Does the 2027 change apply to my practice?

Yes, for almost any practice that bills maternity care. The global package retirement is a CPT code-set change, so it reaches obstetric billing across commercial payers, Medicaid, and Medicare alike. Gynecology codes are not affected; the restructuring applies only to maternity care services.

The most common question we hear from practice managers right now is whether the global codes still work for a delivery that happens in early 2027 when prenatal care started in 2026. The answer is that once the global codes are deleted, retroactive bundling will not be possible, which is why ACOG recommends beginning the E/M transition for antepartum visits during 2026. Several Medicaid programs have already unbundled and use E/M codes for prenatal visits, so many practices are part of the way there. The one group that can relax is gynecology-only billing, which the 2027 restructure leaves untouched. If your denials already cluster around maternity claims, this transition is where they will either shrink or explode, the same way they do around OB claim denials today.

Why the Global Package Is Ending

The global obstetric package was built in the 1990s, when a single physician typically managed a patient’s entire pregnancy from the first prenatal visit through the postpartum check. It paid one bundled fee regardless of how many visits a patient needed or how complex her care was.

That model no longer matches how maternity care is delivered. Pregnancies are increasingly managed by multidisciplinary teams, including OB/GYNs, certified nurse midwives, laborists, and maternal-fetal medicine specialists, often across different facilities. High-risk patients transfer between sites, and bundled codes cannot track who did what. ACOG, whose Committee on Health Economics and Coding drove the change with the AMA, has described the global payment as a longstanding pain point that paid the same whether a patient was seen 4 times or 20.

The signal for practice owners is that maternity reimbursement is moving from predictable and bundled to itemized and documentation-driven. That rewards practices that capture every phase accurately and penalizes those that treat prenatal care as an afterthought to the delivery code.

How will the new maternity codes change reimbursement?

The AMA designed the new code set to be budget-neutral in aggregate, so total maternity spending is not meant to rise or fall on the switch alone. What changes is distribution. High-touch, high-risk, and maternal-fetal medicine practices are best positioned to capture more, because they can now report the extra visits and complexity the global fee erased. Routine, standard-volume practices may see roughly stable revenue but higher administrative cost.

Medicare is a different story. In its CY2027 Physician Fee Schedule proposed rule, CMS estimates obstetrics and gynecology services will decrease by about 2 percent in the facility setting and 1 percent in the office setting, driven largely by the conversion factor cut as the temporary 2026 payment increase expires. Here is how the reporting model changes phase by phase:

Maternity phase	Global package (through 2026)	New model (from January 1, 2027)
Antepartum care	Bundled into 59400, 59510, 59610, 59618	Reported with E/M codes, flagged with modifier TH
Labor management	Bundled into the global code	New stand-alone labor management codes
Delivery	Bundled into the global code	New delivery codes for vaginal and cesarean
Postpartum care	Bundled into the global code	Reported with E/M codes
How it is reported	One global code per pregnancy	Four phases reported separately

Source: AMA CPT 2027 maternity care update and ACOG transition guidance. Medicare impact estimates are from CMS’s CY2027 Physician Fee Schedule proposed rule, which remains open to comment.

What should OB practices do before January 1, 2027?

The window to prepare is now, not December. Work these steps before the deletion takes effect:

• Start reporting antepartum visits with E/M codes during 2026 for any pregnancy that will deliver in 2027, since retroactive bundling will not be possible.
• Append modifier TH to those E/M visits to flag them as maternity care, as ACOG recommends.
• Confirm each payer’s transition policy, because commercial plans, Medicaid, and Medicare are moving at different speeds.
• Train coders and front-office staff on phase-based reporting before the codes go live, not after the first denials.
• Map your delivering providers so labor management and delivery are attributed correctly when care is split across a team.
• Submit a comment to CMS before September 14, 2026, if the proposed G-codes would burden your practice.
• Audit your current global claims now, so you enter 2027 without a backlog straddling two coding systems.

In our experience matching providers with billing partners, a coding transition this large is where under-resourced billing teams fall behind fastest. The practices that come out ahead treated the last half of 2026 as a rehearsal, not a deadline.

The CMS G-Code Complication

The transition would be cleaner if every payer simply adopted the new AMA codes. CMS has proposed something else. Its CY2027 proposed rule, issued July 14, 2026, includes 15 new HCPCS G-codes that would preserve the existing global maternity payment structure for Medicare, sitting alongside the new unbundled CPT codes that also take effect January 1, 2027.

ACOG has objected directly. In a statement from ACOG President Camille A. Clare, MD, the College warned that creating G-codes that mirror the old global structure, even for a single year, would force obstetric practices to learn and operate under two separate billing systems at once, increasing administrative burden and confusion. ACOG also argues the G-codes would divide patients by insurer, undermine price transparency, and risk worsening obstetric care disparities. Its recommendation to CMS is to make a clean break and adopt the new obstetric codes rather than the G-codes. For billing teams, the practical takeaway is to build for the unbundled CPT system while watching the final rule, expected this fall, to see whether Medicare adds a parallel G-code track.

Common Mistakes in the Transition

A change this size creates predictable failure points, and most are avoidable with planning.

The first is billing E/M visits alongside a global code in 2026, which payers still deny as unbundling until the globals are actually retired. The second is assuming the delivery date, not the care dates, controls which system applies; a pregnancy spanning the January 1 boundary needs a clear rule for each phase. The third is treating this as a delivery-code swap and forgetting that antepartum and postpartum move to E/M with modifier TH. The fourth is assuming gynecology is affected and needlessly reworking gyn workflows. Providers often come to us mid-transition, after a payer rejects a claim that mixed old and new codes, which is exactly the scenario a rehearsal period is meant to prevent.

In-House vs Outsourced Billing

Across the billing companies we vet, the OB specialists that are ready for 2027 already moved antepartum visits to E/M coding during 2026 and built payer-by-payer transition matrices. That is the level of preparation this change demands, and it is hard to reach with an overstretched in-house team learning phase-based coding for the first time under deadline. A billing partner fluent in maternity care, not one that handles OB as one specialty among dozens, makes the difference between a smooth switch and a first-quarter cash-flow gap.

That is where OB/GYN Bill Co fits. Every request is reviewed by a real person on the Billing Service Quotes team and matched to billing companies with direct OB/GYN experience, weighed against your practice size, location, EHR system, and payer mix. Many partners are software agnostic and work inside Athenahealth, AdvancedMD, Tebra, Greenway Intergy, or CareCloud without a migration, so a coding transition does not have to become a platform transition too.

Frequently Asked Questions

Next Steps

Still billing the current globals? Review CPT 59400 for vaginal delivery and CPT 59510 for cesarean before they retire.

Fighting maternity denials? See handling claim denials for your OB/GYN practice.

Want help before 2027? Get matched with an OB/GYN billing company that codes maternity phases separately today.