OB/GYN Medical Coding Audits

Why OB/GYN practices need regular coding audits

OB/GYN is one of the hardest specialties to code consistently. A single provider might, in one day, see prenatal visits that fall inside a global package, a problem-oriented visit during pregnancy that doesn't, a well-woman exam with a separately billable problem, an IUD insertion, and a hysteroscopy — each with its own rules.

Without regular review, coding drifts. Providers settle into habits. A biller learns a workaround that gets claims paid but isn't quite right. A payer changes a policy and nobody notices. Over time that drift shows up in two places:

• Revenue you never billed — E/M levels lower than the documentation supports, add-on codes and modifiers that were never reported, separately billable services absorbed into a global.
• Compliance exposure — codes or modifiers that the documentation doesn't support, which can lead to payer recoupments or worse.

An audit gives you a clear, documented picture of both. After more than eight years reviewing OB/GYN claims, we've found that most practices have a handful of repeatable patterns that, once fixed, make a lasting difference.

What we audit

Evaluation and management (E/M) coding

Since the 2021 office E/M changes (and the 2023 expansion to other settings), visit levels are selected by medical decision making (MDM) or total time on the date of the encounter. We check whether the level billed matches the documentation under the method used, whether prolonged services were captured, and whether modifier 25 was used appropriately for a significant, separately identifiable E/M on the same day as a procedure or preventive visit.

Preventive and well-woman visits

Preventive visit codes (99381–99397), the Medicare screening pelvic and breast exam (G0101) and Pap collection (Q0091), and — since 2024 — the pelvic exam add-on 99459 all have specific rules. When a problem is addressed at a preventive visit, both may be billable with the right documentation and modifier.

Global maternity coding

We check package vs. component code selection, antepartum visit counts behind 59425 and 59426, delivery type (including VBAC and trial of labor), multiple-gestation billing, and the diagnosis set on delivery claims. See global maternity billing.

Gynecologic surgery

Approach, uterine weight, adnexal procedures, bundled vs. distinct procedures, NCCI edits, modifier 22, 59 and X-modifier support, and assistant-surgeon billing. See GYN surgery coding.

Diagnosis coding

ICD-10-CM specificity, Chapter 15 sequencing rules for pregnancy, Z37 and Z3A on delivery claims, and diagnosis-to-procedure linkage that supports medical necessity. Our ICD-10 O codes guide covers the sequencing rules.

Charge capture

Are the services performed actually making it onto claims? We commonly look at ultrasounds, non-stress tests, LARC devices and their HCPCS J-codes, in-office procedures, injections and supplies.

Types of audits we offer

Our audit process

1. Scope. We agree on the audit type, time period, providers and sample size.
2. Sample. Claims are selected randomly or by focus area, with the documentation for each.
3. Review. Each claim is coded independently from the record and compared to what was billed.
4. Findings. Every variance is categorized — undercoded, overcoded, unsupported modifier, missed charge, diagnosis issue — with the specific documentation reference.
5. Report. A clear summary with the patterns that matter most, provider-level results, and recommended fixes.
6. Education. We walk providers and staff through the findings, with practical documentation tips.
7. Follow-up. An optional re-audit to confirm the fixes took hold.

The most common findings in OB/GYN audits

These patterns come up again and again:

• E/M levels that don't reflect the MDM documented — more often too low than too high, especially for complex prenatal problem visits.
• Modifier 25 missing or overused on same-day preventive and problem visits or visit-plus-procedure encounters.
• Separately billable services missed during pregnancy — complication visits, ultrasounds, non-stress tests.
• LARC devices billed without the supply code or with the wrong device code.
• Hysterectomy coded without the correct weight tier because the claim was billed before the pathology report.
• Unsupported modifier 59 used to bypass NCCI edits without a distinct site or session documented.
• O80 used with other Chapter 15 codes, or delivery claims missing Z37.

Compliance matters as much as revenue

An audit isn't a license to code higher. Our job is to code accurately. When we find overcoding, we tell you clearly, explain the risk, and recommend how to correct it. When an audit identifies overpayments, there are legal obligations about reporting and returning them; we recommend involving your compliance officer or healthcare attorney in those decisions.

Who performs the audit

Audits are performed by our OB/GYN coding team, drawing on more than eight years of specialty billing and coding experience. We don't outsource audit work, and we don't use automated tools to make coding judgments — each claim is reviewed by a person reading the record.

What a good audit report looks like

A useful audit report is short at the top and detailed underneath. Ours includes:

• Executive summary. The handful of patterns that matter most, in plain language, with the estimated direction of impact (missed revenue or compliance risk).
• Accuracy by category. E/M, procedures, modifiers, diagnoses and charge capture, so you can see where problems cluster.
• Provider-level results. Each provider's findings with specific documentation examples — useful for education and fair to providers who are coding accurately.
• Claim-level detail. Every reviewed claim, what was billed, what the documentation supports, and why.
• Recommendations. What to change in coding rules, templates, charge forms or workflows, ranked by impact.
• Correction list. Claims that can still be corrected within payer filing limits, and any that may need a refund.

Preparing your practice for an audit

You don't need to do much. We'll ask for system access or exported records for the sample period, a list of providers, your current fee schedule, and any recent payer audit letters or denial trends you're worried about. If you have specific concerns — a payer questioning modifier 25, a new provider, a recent jump in CO-97 denials — tell us up front and we'll weight the sample toward those areas.

Request a free sample audit

Message us on WhatsApp. We'll review a small sample of your claims at no cost and show you the kinds of findings a full audit would produce. If you'd like ongoing coding support after the audit, our revenue cycle management service includes continuous pre-bill review.