Blue Cross NC Maternity Billing Update: Modifier TH Required Now for Deliveries Expected in 2027

Blue Cross and Blue Shield of North Carolina (Blue Cross NC) sent the provider notice regarding maternity billing changes in May of 2026, which was updated on September 16, 2026. Maternity billing is changing dramatically before the 1st of January 2027, as maternity services make the transition from bundled reporting to service-level reporting.

In addition to changes in the new 2027 CPT® structure, there are also interim billing requirements that take effect on September 1, 2026 for some deliveries expected in 2027 that must also be accounted for in the transition.

Understanding these changes early can help practices update workflows, strengthen documentation, and reduce coding or claim submission issues during the transition.

What Is Changing in Global Maternity Billing?

Beginning January 1, 2027, the global maternity care and delivery codes will be deleted and replaced with new CPT® codes. The updated structure divides maternity care into four distinct phases:

• Antepartum care: 
• Labor management: 
• Delivery care: 
• Postpartum care: 

This change enables maternity services to be reported more precisely by the services offered, instead of mostly in the form of a single universal service. 

Interim Billing Guidance for Deliveries Expected in 2027

Blue Cross NC's interim rule took effect before the new codes do.For dates of service on or after September 1, 2026, when the delivery is anticipated to occur in 2027, the first prenatal visit after pregnancy confirmation and subsequent antepartum visits should be reported using the applicable E/M service rather than the existing global antepartum codes.

E/M Codes and Modifier TH

Applicable E/M codes are 99202–99205 and 99211–99215. These services should be reported with Modifier TH to identify the visits as maternity-related services.

The claim should also include an appropriate ICD-10-CM diagnosis code, such as:

• Z34.XX when applicable for pregnancy supervision and gestational status
• O09.XX when an applicable high-risk pregnancy diagnosis is documented

Documentation and E/M Coding Requirements

The reported E/M level must follow current CPT E/M coding requirements. Medical records should support the level of service through the applicable medical decision-making or time-based requirements. Providers and coding teams should therefore ensure that the documentation supports both the reported E/M service and the pregnancy-related diagnosis.

Billing for Dates of Service Through August 31, 2026

Prenatal services with dates of service on or before August 31, 2026 should continue to follow the applicable existing antepartum billing structure:

• 59425: 4–6 antepartum visits
• 59426: 7 or more antepartum visits

Preparing for the 2027 Maternity Billing Transition

With the shift from global maternity billing to service-level reporting, OBGYN practices should begin reviewing their workflows. Updating coding systems, strengthening provider documentation, training billing teams, and reviewing E/M, Modifier TH, and diagnosis reporting can help practices adapt to the new requirements. 

As maternity coding continues to evolve, BillingFreedom supports OBGYN practices with experienced medical billing and coding expertise to help keep workflows aligned with current CPT guidance and payer requirements.

What This Means for Your Practice

• Include all Blue Cross NC clients due on or after January 1, 2027. Since September 1, their antepartum visits will be reported out as E/M + TH + Z34/O09. For those who have been holding over the visits for 59425/59426 or the global claim, submit the visits now. 
• Each visit now has to stand on its own as an E/M level. Flowsheet-style prenatal notes will not support a 99213 or 99214; document medical decision-making or time at every visit.
• The notice covers antepartum visits only. Blue Cross NC has not yet said how to bill labor management, delivery or postpartum care in 2027, or what to do if a delivery expected in 2027 arrives early in December. Watch for the next update and ask your provider representative before year-end.
• Pregnancies delivering in 2026 are not affected by this notice. Continue billing them as you do today.
• For the code changes themselves, Blue Cross NC points to the AMA's CPT 2027 Maternity Care Services page and code guidelines PDF.