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AMS Solutions provides OB/GYN medical billing services for obstetrics and gynecology practices nationwide. Physician-founded in 1992 and serving practices in all 50 states, we manage the full revenue cycle with AAPC-certified coders and a dedicated account manager.
“We take care of you, so you can take care of your patients.”
Since 1992, AMS Solutions has handled medical billing for OB/GYN and women’s health practices across the United States. We’re in-house, AAPC-certified, with a signed BAA — and we know OB/GYN coding inside and out, from the global obstetric package to well-woman visits to the upcoming 2027 transition away from bundled maternity codes.
This page walks through how AMS handles OB/GYN billing, the codes and modifiers we work with daily, and what to expect when you partner with us.
Every AMS client is assigned a dedicated billing team led by an Account Manager you can reach directly — no overseas call centers, no phone trees, no handoffs between strangers. Your team is built specifically for OB/GYN coding nuances and the EMR/EHR you already use (Epic, eClinicalWorks, athenahealth, Practice Fusion, and others).
OB/GYN is one of the most complex specialties in medical billing because it bundles months of care into single global codes, requires careful split-billing when care transfers between providers, and is subject to a major 2027 coding overhaul. We’ve built specific operational depth in every part of it.
When a single provider or group manages a complete pregnancy, billing rolls up into one global code:
Each global code bundles approximately 13 prenatal visits, the delivery, and routine postpartum follow-up through 6 weeks.
The global package only applies when a single provider or group manages the entire pregnancy. Real life rarely cooperates. We routinely handle split billing for transfer of care mid-pregnancy, late prenatal entry, insurance change mid-pregnancy, and deliveries performed by a different provider than antepartum care. The codes:
Services that should always be billed separately — and that practices often forget to capture:
Annual gynecological exams, Pap smears, breast exams, and contraceptive management each have specific coding rules under preventive vs. problem-focused E&M. Modifier -25 is required when a problem-focused E&M is performed at the same visit as a preventive service. Our team tracks these distinctions on every claim.
IUD placement (CPT 58300), IUD removal (CPT 58301), Implanon and Nexplanon insertion and removal, and contraceptive counseling each have payer-specific rules and modifier requirements. We bill the device and the procedure separately when the payer requires it.
In 2027, CMS and AMA are phasing out the bundled global-OB codes in favor of discrete service-based codes — meaning each prenatal visit, delivery component, and postpartum service will be billed individually. This is the biggest OB/GYN coding shift in decades, and practices that aren’t ready will see revenue disruption in Q1 2027. We’re already preparing client workflows for the transition.
The AMA releases CPT code updates each year, and 2026 brings several changes relevant to OB/GYN practices. The revised E/M guidelines continue their trajectory toward medical-decision-making (MDM) and time-based coding, including new telehealth codes for postpartum follow-up visits. Modifier 25 guidelines have been tightened — payers now require explicit documentation of a separately identifiable problem-focused service when billed with a preventive visit. MIPS has added new OB/GYN-specific quality measures around prenatal HIV screening, postpartum depression follow-up, and cervical cancer screening timeliness. AMS tracks every coding change through our AAPC-certified coders and adjusts your charge capture workflows proactively, so your practice never falls behind on compliance or reimbursement.
Preventive service billing in OB/GYN is a persistent denial trigger because the distinction between preventive and problem-focused visits is nuanced. Well-woman visits using the preventive medicine evaluation and management codes for new and established patients, selected by age, cover the annual exam, Pap smear, and breast exam — but if the same visit addresses a separate complaint like pelvic pain or abnormal bleeding, modifier 25 is required on the problem-focused E/M code. Medicare’s initial preventive physical exam (IPPE or “Welcome to Medicare”) has different coverage rules than a standard annual visit, and many commercial plans define their own preventive benefit. HPV vaccination administration coding varies significantly by payer; some require the vaccine code alongside a separate administration fee code. Your practice can reduce these denials with specialty-specific workflows. AMS’s credentialing team ensures your payer contracts accurately reflect your preventive service codes.
Even experienced OB/GYN billers leave revenue on the table under the global package. Each global code bundles approximately 13 antepartum visits, the delivery, and 6 weeks of postpartum care — but documentation gaps in visit counting are the most common reason for payer takebacks. Separately billable services during the global period include amniocentesis (CPT 59000), chorionic villus sampling (CVS, CPT 59015), external cephalic version (ECV, CPT 59412), cervical cerclage (CPT 59320), and third- or fourth-degree laceration repair. Payer-specific global definitions vary: Medicare follows the surgical package concept, while many commercial plans define global by the CPT code book. Using modifier 59 appropriately during the global period prevents denied bundles on legitimate separate services. Full RCM services from AMS ensure every billable event is captured.
To maximize reimbursement under the global package, document every antepartum encounter with date, duration, and medical necessity. Track your visit count against the 13-visit standard — if a patient requires more than 13 visits, the additional visits may be separately billable with modifier 25 and the appropriate E/M code. The 2027 unbundling of global maternity codes will fundamentally change this landscape: every component will be billed individually, which means practices that already have strong visit-level documentation will transition smoothly. AMS runs monthly documentation audits to identify missed billables before claims go out.
A practice with $250,000 in monthly collections and an 8% denial rate is leaving roughly $20,000 on the table every month. Cut that denial rate to 4% — realistic when claims are scrubbed properly and denials are worked immediately — and you recover roughly $10,000 a month. That’s $120,000 a year in revenue that was already yours.
Example for illustration purposes only. Actual results vary by specialty, payer mix, volume, workflow, and current billing performance.
Beyond obstetric care, OB/GYN practices perform a range of gynecological procedures, each with its own billing considerations. Here are the most commonly billed categories.
Annual well-woman exams, Pap smear cytopathology, and HPV testing follow specific billing rules. The Affordable Care Act requires coverage of preventive services without patient cost-sharing, but billing them with incorrect diagnosis codes (using a problem-oriented ICD-10 instead of a screening code like Z01.419) can shift the financial responsibility to the patient and create billing complaints.
Billing gets even more layered when your OB/GYN practice also acts as a patient’s primary care provider. A routine annual exam might include a separate gynecological issue, or a prenatal visit could involve managing a non-pregnancy-related condition. Handling these situations correctly comes down to precise documentation and modifier usage. For example, if a provider addresses a significant, separate issue during a routine prenatal visit, you must append modifier -25 to the E/M code to get paid for the extra work. Without it, payers will deny the E/M service as part of the global package. An expert billing partner can manage these complexities for you, preventing costly denials that arise from unbundling errors or incorrect diagnosis codes.
A significant update for gynecological billing is CPT code +99459 for pelvic examinations. Effective since early 2024, this is an “add-on” code, which means you cannot bill it by itself. Instead, you must report it in addition to a primary evaluation and management (E/M) or other procedure code. The key to getting reimbursed for +99459 is documentation. Your provider’s notes must clearly justify why the pelvic exam was medically necessary, linking it to the patient’s history, symptoms, or a shared decision-making process. You should not use this code for routine follow-up visits after surgery, as those services are typically included in the global surgery fee (reported with 99024). Report it only once per patient, per day, even if multiple services are performed. For more detail, the AAPC publishes guidance on this expense-only code.
As women transition into perimenopause and menopause, many seek help from their gynecologist to manage symptoms. This area of care involves a mix of E/M services, diagnostic testing, and prescription management. A gynecologist will typically diagnose menopause by evaluating symptoms, checking hormone levels through lab work, and ruling out other potential health issues. Each of these steps must be coded accurately. Treatment options, such as hormone replacement therapy or other medications to alleviate hot flashes and improve sleep, require ongoing management and follow-up visits. It is important to use the specific ICD-10 codes that reflect the patient’s status and any related conditions. Correctly documenting and coding these services ensures your practice is properly reimbursed for the support you provide during this life stage.
OB/GYN is not a one-size-fits-all specialty, and its sub-specialties introduce more layers of billing complexity. Practices focused on Maternal-Fetal Medicine (MFM), Reproductive Endocrinology and Infertility (REI), or Urogynecology face their own distinct coding challenges. A biller who is proficient in routine global packages may not have the expertise to correctly code a multi-cycle infertility treatment or a complex high-risk pregnancy managed by an MFM specialist. Ensuring your billing team has the specific coding knowledge for your practice’s unique service mix is essential for capturing the full reimbursement you have earned.
Modifiers are the backbone of accurate OB/GYN billing. Using them correctly means the difference between getting paid and getting denied. Here is a breakdown of the modifiers OB/GYN practices use most often.
The four primary global codes are CPT 59400 (vaginal delivery), CPT 59510 (cesarean delivery), CPT 59610 (VBAC delivery), and CPT 59618 (cesarean after attempted VBAC). Each bundles approximately 13 prenatal visits, the delivery, and routine postpartum care through six weeks. These codes remain valid through December 31, 2026.
When prenatal, delivery, and postpartum care are split across practices, the global obstetric package should not be billed. We use split billing instead: antepartum-only, delivery-only, and postpartum-only codes are reported separately, so each provider bills only for the portion of care they actually delivered.
Under the AMA’s CPT 2027 maternity restructure, the global obstetric package codes, CPT 59400 and 16 others, are deleted effective January 1, 2027. They remain valid for dates of service through December 31, 2026. Antepartum and postpartum care move to per-encounter reporting, so practices should plan workflow and system changes before the new year.
AMS operates under signed Business Associate Agreements (BAAs) with every client practice.
We offer a free practice audit. Send us your aging A/R, three months of receivables, and three months of billables. We return a written assessment of your clean claim rate, denial breakdown, days in A/R, and where we see recoverable revenue. No commitment, no obligation.
If you’re considering switching billing partners — or moving from in-house to outsourced for the first time — we offer a free practice audit. Within two weeks you’ll receive a written report covering your clean claim rate, denial breakdown by category, days in AR by payer, and the specific revenue we believe is recoverable. The audit is yours whether you hire us or not.
AMS Solutions provides specialty-specific medical billing across women’s health and related specialty practices. Explore our other specialty billing pages:
The maternity global package, ultrasound, and the GYN procedure codes your team bills most. Save it for your team.
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