2027 Maternity Coding Changes: What Practices Should Watch

Medically reviewed by Sina Haeri, MD, MHSA, maternal-fetal medicine physician.

Maternity coding is changing on 1 January 2027, and the change is larger than the annual code refresh most practices plan around. The bundled global obstetric codes are being deleted and replaced with reporting across four separate phases of care. That part is decided. What is not decided is whether Medicare will actually use the new structure, and what commercial payers and state Medicaid programs will do.

What is decided

The AMA CPT Editorial Panel accepted the restructuring of maternity care services at its September 2025 meeting, effective 1 January 2027. Seventeen codes are deleted, including the global obstetric codes that most obstetric practices bill today, and twelve new codes are added with revised guidelines.

Under the new structure, maternity care is reported across four phases rather than as a single bundled episode: antepartum care, labor management, delivery, and postpartum care. Antepartum care is no longer a bundled block. It is reported per encounter using standard evaluation and management codes. Labor management gets a new set of codes split by initial and subsequent day and by complexity, reported once per calendar date per patient regardless of the number of fetuses. Immediate postpartum care on the day of delivery stays inside the delivery code, and postpartum care on later dates is reported as evaluation and management.

AMA CPT Editorial Panel, Summary of Panel Actions, September 2025 meeting, Tab 30. The May 2026 and February 2026 panel meetings contain no further maternity actions.

What is not decided

On 14 July 2026 CMS released the CY2027 Physician Fee Schedule proposed rule. It proposes to recognize the new CPT maternity codes and, at the same time, to create a set of new HCPCS G-codes that would reproduce the current global maternity structure for Medicare. CMS gave its reasoning plainly: it is concerned that adopting the new codes outright would be disruptive given how the existing structure is built into current practice patterns.

ACOG and the Ob Hospitalist Group have both publicly opposed that approach and urged CMS to adopt the new codes without the parallel G-code set. The comment period closes 14 September 2026 and the final rule is expected in early November, so nothing about the Medicare side is settled yet.

Two other things are open. The descriptor wording for the new codes is still in copyediting, and the AMA directs users to the CPT 2027 Professional Edition for final language, which had not been published as of this writing. And no payer outside Medicare is obliged to follow either path. Commercial payers and state Medicaid programs each set their own adoption timing, which for most obstetric practices is the larger share of the book.

CMS-1848-P, CY2027 Medicare Physician Fee Schedule proposed rule, released 14 July 2026 and published in the Federal Register 16 July 2026. ACOG and OBHG positions as reported by Contemporary OB/GYN, 24 July 2026, and the Ob Hospitalist Group, 29 July 2026.

Why it matters to an obstetric practice

A bundled code and a set of per-encounter codes produce revenue on different schedules. Under the global package, a practice submits after delivery and receives one payment for the episode. Under per-encounter antepartum reporting, the practice bills as care is delivered. That changes cash timing, claim volume, and the amount of documentation supporting each claim.

It also changes what happens when care transfers. Today, a patient who moves between practices partway through a pregnancy triggers an unbundling exercise. Under per-encounter reporting, each practice reports the visits it provided and the question largely resolves itself. Practices that refer high-risk patients out will see the effect of that decision on the claim rather than at the end of the episode.

The operational risk is the transition itself. A practice will be working two structures at once for some period, because payers will not move on the same date, and pregnancies in progress on 1 January will span both.

What to do now, and what to wait on

Worth waiting on: the CY2027 final rule in early November, which settles the Medicare G-code question, and the CPT 2027 Professional Edition, which settles the descriptor language. Building billing rules or staff training against either one before it publishes is work you will do twice.

A note on ICD-10-CM

Separately from the CPT change, the FY2027 ICD-10-CM code set takes effect on 1 October 2026, ahead of the coding change above. It includes a new obstetric subcategory for continuing pregnancy after vanishing twin syndrome, stratified by trimester and by fetus, which previously had no dedicated way to be documented.

CMS, ICD-10-CM FY2027 files, effective 1 October 2026 through 30 September 2027. The FY2027 Official Coding Guidelines had not been published as of 18 August 2026.

Where Ouma fits

Ouma is a physician-led maternal-fetal medicine practice, not a billing company, so this page is context rather than advice. Where it touches what we do is the referral decision: under either structure, a practice that keeps a high-risk patient and brings subspecialty input in remotely keeps the work.

Related: The global OB package and referrals · Billing obstetric telehealth visits · Ouma for clinics

CPT is a registered trademark of the American Medical Association. Descriptions here are written by Ouma Health and are not the official CPT descriptors. This is general information, not coding or billing advice. Verify current codes and payer policy before submitting claims.