Internal Coding Audit Checklist for OB/GYN Practices

An internal coding audit is the single most effective way to find out whether your OB/GYN coding is accurate — before a payer does. You don't need a large compliance department to run one. You need a sample, a checklist, the documentation, and the discipline to act on what you find.

This checklist covers the highest-risk areas in OB/GYN coding and how to turn findings into improvement.

Before you start

• Define the purpose. General accuracy check, a focused topic (for example modifier 25), or a new-provider review?
• Choose the period. Usually the last three to six months.
• Choose the reviewer. Someone who didn't code the claims originally, with OB/GYN coding knowledge.
• Gather references. Current CPT and ICD-10-CM, NCCI edits, payer policies for your top payers.
• Decide how you'll record findings — a simple spreadsheet works.

Step 1: Pull a representative sample

• Include every provider (physicians, midwives, NPs).
• Mix visit types: new and established E/M, preventive, prenatal problem visits, procedures, deliveries, surgery.
• Mix payers.
• Select randomly within each group — not just the easiest or most recent charts.
• Add targeted claims for known risk areas (high-dollar surgery, frequent modifiers).

Step 2: Global vs. itemized maternity

For each delivery and each pregnancy that ended without delivery at your practice:

• Was the global code used only when your group provided all antepartum, delivery and postpartum care?
• Were antepartum components billed correctly by visit count (E/M for 1–3, 59425, 59426)?
• Is the delivery family correct (vaginal, cesarean, VBAC, cesarean after attempted VBAC)?
• Were insurance changes handled with split billing?
• Were transfers out billed at all?

See itemized vs. global maternity billing.

Step 3: High-dollar surgical codes

• Approach matches the operative note, including conversions
• Hysterectomy and myomectomy weight/number tiers match pathology
• Adnexal procedures captured in the right code
• No separately billed bundled services (diagnostic laparoscopy, lysis of adhesions, routine cystoscopy)
• Modifiers 22, 59/X, 50, 62, 80/82 supported by documentation and payer rules

See GYN surgery coding mistakes.

Step 4: Diagnosis coding

• O codes sequenced correctly; trimester characters match gestational age on the date of service
• Z34 not used with O codes; O09 used for high-risk supervision
• Z3A and Z37 on delivery claims
• O80 used only for uncomplicated vaginal deliveries, alone
• Surgical diagnoses match pathology

Step 5: E/M levels

• Level supported by medical decision making or total time
• Time documented when used
• New vs. established patient status correct
• Modifier 25 used only for significant, separately identifiable E/M

Look for patterns by provider: a provider who bills almost every visit at the same level, or whose distribution differs sharply from peers, deserves a closer look in either direction.

Step 6: Modifier usage

• 25 with preventive visits and minor procedures — documentation supports separate work
• 59/X — distinct services documented
• 24, 58, 78, 79 — global period situations correct
• 95/93 — telehealth modality matches documentation and payer rules
• TH — used where payers require it

Step 7: Charge capture

• Ultrasounds billed with the right code for gestational age and exam type, with reports and images
• LARC device J-codes billed when the practice purchased the device
• 99459 pelvic exam add-on used appropriately
• Non-stress tests and complication visits during pregnancy captured

Step 8: Record and score findings

For each claim, record: what was billed, what the documentation supports, the variance type (undercoded, overcoded, unsupported modifier, missed charge, diagnosis error) and the reference. Calculate accuracy by provider and by category.

Step 9: Act on the findings

1. Correct claims still within filing limits where undercoding is clear.
2. Address overpayments with your compliance officer or attorney.
3. Educate providers with specific examples from their own notes.
4. Fix systems — templates, charge forms, scrubber rules.
5. Re-audit in three to six months to confirm improvement.

Common findings

• E/M levels inconsistent between providers
• Hysterectomy claims billed before pathology
• LARC device codes missing
• Modifier 25 used by habit
• Transfers out never billed

Sample audit worksheet columns

A simple spreadsheet is enough to run a credible internal audit. Use columns such as:

Keep the worksheet with the audit report so you can show what was reviewed and how conclusions were reached.

How to talk to providers about findings

• Share findings privately and promptly
• Lead with patterns, not individual mistakes
• Use the provider's own notes as examples
• Show what documentation would support the intended code
• Agree on one or two changes, then re-audit

When to bring in an outside auditor

Internal audits are valuable, but an independent review adds objectivity — especially for new providers, high-risk areas, payer audit responses or when the internal team coded the claims. Our coding audits provide provider-level findings and education. Send us a WhatsApp message for a free sample audit.