OB Ultrasound Billing Guide: CPT 76801, 76805, 76811, 76815, 76816 and 76817

Ultrasound is one of the few services during pregnancy that's billed outside the global maternity package, which makes it an important — and frequently mishandled — revenue line. Choosing between 76801, 76805, 76811, 76815, 76816 and 76817 depends on gestational age, the scope of the exam, the approach and the number of fetuses. Payers add frequency limits and diagnosis requirements on top.

This guide covers code selection, multiple gestations, combinations, diagnosis coding and the documentation that supports payment.

Obstetric ultrasound codes at a glance

Choosing the right code

Complete vs. limited vs. follow-up

• Complete (76801, 76805): the full set of elements described in CPT for the trimester — for example, at 14 weeks or later, fetal number, presentation, cardiac activity, amniotic fluid, placental location, fetal biometry and an anatomic survey.
• Limited (76815): a focused exam answering a specific question — is there a heartbeat, where's the placenta, what's the presentation, how much fluid.
• Follow-up (76816): re-evaluation of something already assessed — fetal growth, fluid, or an abnormality identified on a prior scan.

If the report doesn't document all the elements of a complete exam, the complete code isn't supported. That's one of the most common audit findings for OB ultrasound.

Gestational age

76801 vs. 76805 turns on 14 weeks 0 days. Use the gestational age on the date of the exam, from the best obstetric estimate in the record.

Detailed anatomic exam

76811 describes a more extensive evaluation than 76805, generally performed for a known or suspected fetal anomaly or a high-risk maternal or fetal condition. Payers often limit it to one per pregnancy per practice and expect a high-risk indication — commonly performed by maternal-fetal medicine specialists. Don't report 76805 and 76811 for the same fetus on the same date.

Transvaginal exams

76817 is a transvaginal obstetric ultrasound. When both a transabdominal (76801 or 76805) and a transvaginal exam are medically necessary on the same date — for example to evaluate the cervix or an early pregnancy that's hard to see transabdominally — many payers allow both with documentation of why both were needed. Some require a modifier. Check the payer's policy before billing both.

Multiple gestations

Professional and technical components

When the practice owns the equipment and performs and interprets the exam, bill the global service (no modifier). When the exam is performed at a hospital or imaging center and the physician only interprets it, bill the professional component with modifier 26. A facility or entity that only performs the technical portion bills with TC.

Diagnosis coding for OB ultrasound

Payers decide medical necessity largely from the diagnosis:

• Routine screening: codes from category Z36 (encounter for antenatal screening of mother) — for example Z36.3 (screening for malformations), Z36.4 (screening for fetal growth retardation), Z36.87 (encounter for uncertain dates) or Z36.89 (other specified antenatal screening). Pair with Z3A and, where appropriate, Z34 or O09 codes per sequencing rules.
• Diagnostic exams: the O code for the condition being evaluated — for example O36.59- (maternal care for known or suspected poor fetal growth), O41.0- (oligohydramnios), O44.- (placenta previa), O30.- (multiple gestation) — with the seventh character for the affected fetus where required.
• Symptoms: when the exam is driven by symptoms such as bleeding in pregnancy, use the appropriate O code (for example O20.- for hemorrhage in early pregnancy).

The diagnosis linked to each ultrasound should match the indication documented in the order and report.

Frequency limits

Many payers limit routine obstetric ultrasounds in low-risk pregnancies — for example, one or two complete exams per pregnancy — while allowing additional exams with documented high-risk indications. Limits differ by payer and are often published in a medical policy on obstetric ultrasound. Practical steps:

• Track how many ultrasounds each patient has had and with which codes.
• Check the payer's policy before scheduling repeat or follow-up exams in low-risk pregnancies.
• Make sure the indication for each additional exam is documented and coded.

Documentation requirements

For an ultrasound to be billable, the record should include:

• A signed, final interpretation and report by the physician
• Permanently recorded images, retained in the record
• The indication for the exam
• The elements examined — sufficient to support a complete, limited, follow-up or detailed code
• For multiple gestations, findings for each fetus

A bedside "quick look" without a report and stored images generally isn't separately billable.

Common OB ultrasound billing errors

1. Billing 76805 when the report documents only limited elements (should be 76815)
2. Billing 76801 after 14 weeks 0 days (or 76805 before)
3. Reporting 76815 once per fetus (it's once per exam)
4. Reporting 76816 once for twins (it's per fetus)
5. Billing 76805 and 76811 for the same fetus on the same date
6. Missing modifier 26 for hospital-performed exams the physician interprets
7. Using a screening diagnosis for an exam driven by a complication — or vice versa
8. Exceeding payer frequency limits without documented indications

Ultrasound after the 2027 maternity changes

Obstetric ultrasound remains separately reportable under the CPT 2027 maternity structure. What changes is the context: prenatal visits themselves will be billed per encounter starting January 1, 2027, so the visit E/M, any ultrasound and any other procedures on the same day will all be on the claim together — making consistent diagnosis coding across them more important. See our 2027 maternity transition guide.

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