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CurrentAmbetter NevadaPolicy CP.MP.38

Ultrasound in Pregnancy

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Medical necessity criteria and coding guidance for obstetric ultrasound exams during pregnancy for members of Ambetter Nevada (Centene-affiliated health plans). Applies to providers ordering and billing ultrasound services in pregnancy.

Policy Summary

PayerAmbetter Nevada

PolicyUltrasound in Pregnancy

Policy CodePolicy CP.MP.38

Change TypeNo material changes

Effective Date

Next Review Date

Key ActionBill covered ultrasound CPT codes only when supported by an appropriate diagnosis from the policy's ICD-10 lists and document clinical indications to demonstrate medical necessity.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

1standard first trimester ultrasound allowed per pregnancy (76801)

1standard second/third trimester ultrasound allowed per pregnancy (76805)

1+detailed anatomic ultrasound allowed per pregnancy (76811) with supporting high-risk diagnosis

up to 13transvaginal ultrasounds allowed per pregnancy for indicated cervical/placental assessment

3D/4Dconsidered not medically necessary

Table 4 updatedDiagnosis codes supporting first detailed fetal ultrasound updated Oct 2023

Coverage Criteria for Ultrasound in Pregnancy

First Trimester Ultrasound

Standard first trimester ultrasound (76801) coverage rule

First Trimester Standard Ultrasound: One standard first trimester ultrasound (76801) is allowed per pregnancy before 14 weeks 0 days; subsequent standard first trimester ultrasounds are considered not medically necessary unless the exam is billed as a limited or follow-up assessment (CPT 76815 or 76816).1 per pregnancy

When performed transvaginally, use CPT 76817 (see TVU rules).

Second/Third Trimester Ultrasound

Standard second/third trimester ultrasound (76805) coverage rule

Second/Third Trimester Standard Ultrasound: One standard second or third trimester ultrasound (76805) is allowed per pregnancy after 14 weeks 0 days; subsequent standard second/third trimester ultrasounds are considered not medically necessary when a limited or follow-up ultrasound (CPT 76815 or 76816) would suffice.

Policy Summary

PayerAmbetter Nevada

PolicyUltrasound in Pregnancy

Policy CodePolicy CP.MP.38

Change TypeNo material changes

Effective Date

Next Review Date

Key ActionBill covered ultrasound CPT codes only when supported by an appropriate diagnosis from the policy's ICD-10 lists and document clinical indications to demonstrate medical necessity.

SourceLink

On This Page

Used for fetal presentation, biometry, amniotic fluid, placental position, and anatomic survey.

Detailed Anatomic Ultrasound

Detailed anatomic ultrasound (76811) coverage rule

Indications for 76811: One detailed anatomic ultrasound (76811) is allowed per pregnancy when performed to evaluate suspected fetal anomaly based on history, laboratory abnormalities, clinical evaluation, or suspicious results from a limited or standard ultrasound; additional indications include possible fetal growth restriction and multifetal gestation. This exam must be billed with an appropriate high-risk diagnosis code from the policy's Table 4.1 per pregnancy (unless extenuating circumstances)

A second 76811 is considered medically necessary if care is transferred to a new maternal-fetal medicine practice, a second opinion is required, or the patient is referred to a tertiary center for anticipated delivery of an anomalous fetus; further repeats are not medically necessary.

Transvaginal Ultrasound

Transvaginal ultrasound (76817) coverage rule

Transvaginal Ultrasound Indications: Transvaginal ultrasound (76817) is medically necessary in the first trimester for the same indications as the standard first trimester exam, and later in pregnancy to assess cervical length, evaluate placenta location in placenta previa, or after an inconclusive transabdominal ultrasound. Cervical length screening frequency follows the Berghella approach for women with prior preterm birth or a shortened cervix.Up to 13 per pregnancy as indicated

When performed transvaginally, report CPT 76817; Table 1 specifies start/end weeks, frequency, and maximum allowed TVUs (e.g., maximum # TVU revised to 11 for certain prior preterm birth categories and total allowed TVUs per pregnancy changed to 13).

Not Medically Necessary

Not medically necessary conditions

Not Medically Necessary: 3D and 4D ultrasounds; ultrasounds performed solely to determine fetal sex or to provide parental photographs; growth scans performed less than two weeks apart; ultrasound to confirm pregnancy in the absence of other indications; and first trimester follow-up ultrasound in the absence of pain or bleeding are considered not medically necessary.

Further detailed anatomic ultrasounds beyond the limited permitted circumstances lack evidence of clinical utility and are considered not medically necessary.

Diagnosis-supported ultrasound and TVU frequency rules

Policy links specific ICD-10 diagnoses to medical necessity for detailed fetal ultrasound and defines frequency limits for transvaginal ultrasound surveillance.

Diagnosis-supported detailed fetal ultrasound: A detailed fetal ultrasound (76811) is supported when an appropriate diagnosis from Table 4 (Diagnosis Codes that Support Medical Necessity for First Detailed Fetal Ultrasound) is present; Table 4 was updated (Oct 2023) to include specific ICD-10 codes and ranges such as A92.5, D56.0-D56.9, D57.00-D57.819, M32.0-M32.9, N18.9, and multiple obstetric code ranges.Diagnosis in Table 4

Providers should bill with one of the listed high-risk diagnosis codes to demonstrate medical necessity for 76811 (see updated Table 4 entries).

TVU frequency rules: Transvaginal ultrasound frequency limits and surveillance rules apply as specified in Table 1 and the revision history; total allowed TVUs per pregnancy was revised to 13. For women with TVU cervical length 25–29 mm the frequency may be increased to weekly per the revision note; specific maximum numbers by prior preterm birth category are enumerated (e.g., max 11 TVUs for prior preterm birth 14–27 weeks).Total TVUs per pregnancy = 13 (as revised)

Revision history documents changes to cervical length thresholds and frequency (e.g., <= 25 mm before 24 weeks; increase to weekly for 26–29 mm in certain revisions).

The policy explicitly excludes certain ultrasound services as not medically necessary. This includes 3D and 4D ultrasounds, which the policy states lack sufficient evidence of clinical utility compared with two-dimensional ultrasound, and ultrasound exams performed solely to determine fetal sex or to provide parental photographs. The policy also lists related scenarios considered not medically necessary such as growth scans performed less than two weeks apart, ultrasound to confirm pregnancy in the absence of other indications, and first-trimester follow-up ultrasound without pain or bleeding.

Revision history notes indicate that the document text was edited to remove the term 'experimental' from Section V; however, the available chunks do not include a separate explicit exclusion list beyond the not medically necessary items already described. The change documented in the revision log clarifies wording in Section III and removes the 'experimental' label from Section V without adding new explicit exclusions in these excerpts.

Where state Medicaid coverage provisions conflict with this clinical policy, the state Medicaid provisions take precedence. Providers should consult the applicable state Medicaid manual for any differing coverage rules and follow those provisions for Medicaid members; similarly, Medicare NCDs/LCDs should be reviewed and followed for Medicare members.

The policy limits additional detailed anatomic ultrasounds: a single detailed anatomic ultrasound (76811) is allowed per pregnancy when supported by appropriate high-risk indications, and further detailed repeats are considered not medically necessary except in defined circumstances (for example, change in provider, second opinion, or tertiary transfer). The policy also identifies situations that render additional imaging not medically necessary, reiterating that scans done too frequently (e.g., growth scans less than two weeks apart) and non-diagnostic or convenience exams (sex-only, photo-only, pregnancy confirmation without other indications) are not medically necessary. Revision edits added the term 'detailed' to clarify that multiple detailed anatomic examinations generally lack evidence of benefit.

Background updates and minor rewording noted in the revision log are described as having no impact on the criteria. The revision history indicates background text was updated and coding tables adjusted, but these changes did not alter the policy’s medical necessity criteria in the provided excerpts.

CPT and ICD-10 Coding Guidance

Covered CPT Codes (when supported by appropriate diagnosis)CPTCovered

76801	Ultrasound, pregnant uterus, real time with image documentation, fetal and maternal evaluation, first trimester (<14 weeks 0 days), transabdominal approach; single or first gestation
76805	Ultrasound, pregnant uterus, real time with image documentation, fetal and maternal evaluation, after first trimester (≥14 weeks 0 days), transabdominal approach; single or first gestation
76811	Ultrasound, pregnant uterus, real time with image documentation, fetal and maternal evaluation plus detailed fetal anatomic examination, transabdominal approach; single or first gestation
76817	Ultrasound, pregnant uterus, real time with image documentation, transvaginal

Follow-up / Limited CPT CodesCPT

76815	Ultrasound, pregnant uterus, real time with image documentation, limited (e.g., fetal heart tones, fetal position, fluid) — used as focused reassessment/follow-up
76816	Ultrasound, pregnant uterus, real time with image documentation, follow-up or detailed reexamination of specific organ/system known or suspected to be abnormal

CPT Codes considered Not Medically NecessaryCPTNot Covered

76376	3D rendering with interpretation and reporting of computed tomography, magnetic resonance imaging, ultrasound, or other tomographic modality with image postprocessing under concurrent supervision; not requiring image postprocessing on an independent workstation
76377	3D rendering with interpretation and reporting of computed tomography, magnetic resonance imaging, ultrasound, or other tomographic modality with image postprocessing under concurrent supervision; requiring image postprocessing on an independent workstation

ICD-10 Codes that support medical necessity for detailed fetal ultrasoundICD-10Covered

A92.5	Zika virus disease
B06.00-B06.9	Rubella [German measles]
B50.0-B54	Malaria
B97.6	Parvovirus as the cause of diseases classified elsewhere
D56.0-D56.9	Thalassemia
D57.00-D57.819	Sickle-cell disorders
E66.01	Morbid (severe) obesity due to excess calories [severe obesity with a BMI of 35 or >]
O09.511-O09.519	Supervision of elderly primigravida
M32.0-M32.9	Systemic lupus erythematosus (SLE)
M33.00-M33.99	Dermatopolymyositis

1–10 of 12

1/2

Diagnosis ICD-10 codes and ranges shown in documentICD-10

O14.10	Severe pre-eclampsia
O14.12-O14.13	Severe pre-eclampsia
O14.20	HELLP syndrome (HELLP)
O14.22-O14.23	HELLP syndrome (HELLP)
O14.90	Unspecified pre-eclampsia
O14.92-O14.93	Unspecified pre-eclampsia
O15.00	Eclampsia complicating pregnancy
O15.02-O15.03	Eclampsia complicating pregnancy
O15.9	Eclampsia, unspecified as to time period
O16.2-O16.3	Unspecified maternal hypertension

1–10 of 26

1/3

ICD-10 codes referencedICD-10

O31.33X0-O31.33X9	Specified obstetric codes listed in document
O31.8X20-O31.8X29	Specified obstetric codes listed in document
O31.8X30-O31.8X39	Specified obstetric codes listed in document
O31.8X90-O31.8X99	Specified obstetric codes listed in document
O32.0XX3-O32.0XX9	Specified obstetric codes listed in document
O32.1XX1	Specified obstetric code listed in document
O32.2XX1	Specified obstetric code listed in document
O32.3XX1	Specified obstetric code listed in document
O32.6XX1	Specified obstetric code listed in document
O32.8XX1	Specified obstetric code listed in document

1–10 of 36

1/4

Additional ICD-10 codes referencedICD-10

O42.012-O42.02	Specified obstetric codes listed in document
O42.10	Specified obstetric code listed in document
O42.112-O42.119	Specified obstetric codes listed in document
O42.912-O42.919	Specified obstetric codes listed in document
O43.012-O43.019	Specified obstetric codes listed in document
O43.022-O43.029	Specified obstetric codes listed in document
O43.112-O43.119	Specified obstetric codes listed in document
O43.122-O43.129	Specified obstetric codes listed in document
O43.212-O43.219	Specified obstetric codes listed in document
O43.222-O43.229	Specified obstetric codes listed in document

1–10 of 22

1/3

Additional ICD-10 and public health codesICD-10

O46.029	Specified obstetric code listed in document
O46.092-O46.099	Specified obstetric codes listed in document
O46.8X2-O46.8X9	Specified obstetric codes listed in document
O46.90	Specified obstetric code listed in document
O46.92-O46.93	Specified obstetric codes listed in document
O48.0-O48.1	Specified obstetric codes listed in document
O60.00-O60.03	Specified obstetric codes listed in document
O60.10X0-O60.14X9	Specified obstetric codes listed in document
O98.012-O98.119	Specified obstetric infection-related codes listed in document
O98.919	Specified obstetric infection-related code listed in document

1–10 of 17

1/2

TVU cervical length threshold and frequency rules

TVU cervical length thresholdCervical length ≤ 25 mm before 24 weeks is the threshold prompting increased surveillance; revision clarifies wording to ‘<= 25 mm’.

Increased-frequency bandFor cervical length in the 26–29 mm range, increase surveillance to weekly (revision changed wording from ‘25–29 mm’ to ‘26–29 mm’ in one note).

Maximum TVU allowance per pregnancyTotal allowed transvaginal ultrasounds (TVUs) per pregnancy updated to 13 in the revision history.

Prior preterm birth TVU maximumsMaximum number of TVUs edited to up to 11 for prior preterm birth at 14–27 weeks, and up to 9 for prior preterm birth at 28–36 weeks.

Documentation of changeRevision log documents removal of ‘experimental’ designation from Section V and updates to header wording and references; changes to TVU frequency appear in Section IV, Table 1.

Provider Actions, Billing and Documentation

Prior Authorization

Bill CPT only with supporting diagnosis from Table 4

CPT codes listed in the policy (e.g., 76801, 76805, 76811, 76817, 76815, 76816, 76376, 76377) are covered only when billed with an appropriate supporting diagnosis from the policy's ICD‑10 lists (Table 4); inclusion in the code list does not guarantee payment — providers should verify coding and medical necessity prior to claim submission.

Use the CPT that reflects the procedure performed (e.g., 76817 for transvaginal exams per chunk 5).
Bill detailed anatomic ultrasound (76811) only with an appropriate high‑risk diagnosis from Table 4 (chunks 12, 34–36).
Inclusion of a CPT in the policy is not a guarantee of coverage; documentation must support medical necessity (chunk 47).

Note

No active prior authorization stated in this document

The policy text and revision history show prior authorization language was removed in past updates; no active prior authorization requirement is specified in the cited chunks.

Revision history notes: 'Removed prior authorization language' (chunk 28).
Providers should still follow any plan‑level authorization procedures if separately required by the payer (see contract/plan documents) (chunk 28).

Prior Authorization

Follow state Medicaid and Medicare coverage/prior authorization rules

When state Medicaid rules or Medicare NCDs/LCDs differ from this clinical policy, those state or Medicare coverage provisions supersede — providers must follow state/Medicare prior authorization and coverage rules where applicable.

For Medicaid members, state Medicaid coverage provisions take precedence (chunk 49).
Review applicable Medicare NCDs/LCDs and Coverage Articles before applying this policy (chunk 49).

Step Therapy

Use focused follow‑up codes (e.g., 76816) after 76811

When follow‑up imaging is needed after a detailed anatomic exam (76811) for a suspected anomaly, use focused/follow‑up codes (for example, 76816) rather than repeating another full 76811 except in defined circumstances such as change in provider, second opinion, or tertiary transfer.

Use 76816 for focused reassessment of specific measurements or a detailed reexamination of a known/suspected abnormal organ/system (chunk 12).
A second full 76811 is appropriate only for extenuating circumstances (new provider, second opinion, tertiary referral) (chunk 12).

Billing Rule

Adhere to TVU frequency limits and increased surveillance rules

Transvaginal ultrasound (TVU, 76817) frequency is limited by the policy: total TVUs allowed per pregnancy are defined (changed to 13 in revisions) and increased surveillance frequencies apply for shortened cervical length per the Berghella‑style schedules.

Total allowed TVUs per pregnancy: up to 13 (chunk 3; revision note in chunk 31).
Cervical length screening schedules and maximums (e.g., up to 11 TVUs for prior preterm birth 14–27 weeks) and increased frequency to weekly for TVU cervical length 25–29 mm are specified (chunks 3, 31).
Use CPT 76817 when exam is transvaginal (chunk 5).

Note

Revision history: prior authorization removed; coding and frequency clarified

Historical revision note: prior authorization language was removed and coding/diagnosis/frequency requirements were clarified in multiple updates; providers should be aware of these historical changes when interpreting current criteria.

Revision history documents removal of prior authorization language and updates to TVU limits and ICD‑10 code tables (chunks 28, 31).
Table 4 (diagnosis codes supporting first detailed fetal ultrasound) was updated Oct 2023 (chunk 34).

Documentation Required

Document clinical question(s) and relevant ultrasound findings

Document all ultrasound exams with the clinical question(s) being answered and relevant findings (e.g., gestational age, fetal number, viability, placental location) to demonstrate medical necessity.

Exams should be conducted only when indicated and must be appropriately documented (chunk 1).
Standard first trimester exam elements and when to code as transvaginal (76817) are described and should be reflected in documentation (chunk 5).

Documentation Required

Document and bill with ICD‑10 diagnosis codes from Table 4 when billing 76811

When billing for a detailed fetal ultrasound (76811), include an appropriate ICD‑10 diagnosis code from the policy's listed ranges (Table 4) to support medical necessity.

Table 4 lists diagnosis codes and ranges that support a first detailed fetal ultrasound; updated codes were added in Oct 2023 (chunks 12, 34).
Providers should select the ICD‑10 code that best matches the clinical indication and include it on the claim to justify 76811 (chunks 12, 34–36).

Documentation Required

Claims must follow contract, state, and Medicare rules and be supported by documentation

Providers submitting claims must adhere to their contract terms and applicable state/Medicare coverage provisions; complete documentation must be available to support medical necessity and coverage determinations.

Coverage decisions remain subject to contract terms, state and federal requirements, and plan administrative policies (chunk 47).
State Medicaid and Medicare NCD/LCD provisions may supersede this policy; review those sources as applicable (chunk 49).

Denial Risk

Avoid billing for 3D/4D, sex‑only, photo‑only, or too‑frequent growth scans

Do not bill for 3D/4D rendering codes or exams performed solely to determine fetal sex, provide photographs, or for growth scans done less than two weeks apart — these services are considered not medically necessary and may be denied.

3D/4D ultrasounds and CPTs 76376/76377 are listed as not medically necessary (chunk 14).
Ultrasounds solely for fetal sex determination or parental photographs are explicitly not medically necessary (chunk 4).
Growth scans performed <2 weeks apart and routine first‑trimester follow‑up without pain/bleeding are also not medically necessary (chunks 4, 3).

Note

Policy now focuses on coding, diagnosis support, and frequency limits (historical prior‑auth removed)

Prior authorization language was removed historically; the policy now emphasizes coding, diagnosis linkage, and frequency limits (e.g., TVU limits) as determinants of coverage decisions.

Revision log documents removal of prior authorization language and subsequent focus on coding and frequency rules (chunks 28, 31).
Providers should ensure claims meet the policy's coding/diagnosis/frequency criteria to avoid denials (chunks 12, 31).

Denial Risk

Follow applicable state Medicaid or Medicare NCD/LCD guidance when it conflicts with this policy

Coding in the policy has been reviewed; if state Medicaid or Medicare NCD/LCDs conflict with this policy, those external coverage determinations take precedence and failing to follow them may trigger claim denial.

Coding reviewed and references updated per the revision notes (chunk 40).
State Medicaid provisions and Medicare NCDs/LCDs may supersede this policy — review them before billing (chunk 49).

Definitions and Exam Descriptions

Standard First Trimester Ultrasound (76801)

Definition (CPT 76801)Standard first trimester ultrasound performed before 14 weeks 0 days; may be transabdominal, transvaginal, or transperineal and assesses presence, size, location, and number of gestational sac(s).

Appropriate approach codingWhen performed transvaginally, use CPT code 76817 per policy instructions.

Permitted frequencyOne standard first trimester ultrasound (76801) is allowed per pregnancy before 14 weeks 0 days; additional first-trimester imaging should be billed as limited/follow-up (76815/76816) when appropriate.

Standard Second/Third Trimester Ultrasound (76805)

Definition (CPT 76805)Standard second/third trimester ultrasound performed after 14 weeks 0 days evaluating fetal presentation and number, amniotic fluid, cardiac activity, placental position, fetal biometry, and an anatomic survey.

Common indicationsIncludes screening for fetal anomalies, estimation of gestational age, evaluation of growth, vaginal bleeding, suspected multiple gestation, and assessment prior to procedures (e.g., amniocentesis).

Permitted frequencyOne standard second/third trimester ultrasound (76805) is allowed per pregnancy after 14 weeks 0 days; subsequent exams should use limited/follow-up codes (76815/76816) when appropriate.

Detailed Anatomic Ultrasound (76811)

Definition (CPT 76811)Detailed anatomic ultrasound: a comprehensive fetal anatomic examination performed when there is increased risk or suspicion of fetal anomaly based on history, laboratory abnormalities, or prior imaging findings.

Frequency and limitsTypically limited to one medically indicated 76811 per pregnancy; a second 76811 may be allowed for change in provider, second opinion, or tertiary transfer; further repeats are not medically necessary except in extenuating circumstances.

Follow-up codingWhen follow-up imaging is needed after 76811 for focused reassessment or detailed re-examination of a specific organ/system, use CPT 76816 rather than repeating 76811 in most cases.

Transvaginal Ultrasound (76817)

Definition (CPT 76817)Transvaginal ultrasound of a pregnant uterus used in the first trimester for the same indications as the standard first trimester exam and later in pregnancy to evaluate cervical length and placental position relative to the internal os.

Indications across gestationTVU is medically necessary in first trimester for standard indications, and later for cervical length assessment, placenta previa evaluation, or after inconclusive transabdominal ultrasound.

Coding noteUse CPT 76817 when the exam is performed transvaginally; frequency limits for TVU are specified elsewhere in the policy (up to 13 per pregnancy as indicated).

TVU: Definition and Frequency Notes

TVU definition and scopeTransvaginal ultrasound (TVU) is defined as the transvaginal approach used for first trimester evaluation and later for cervical/placental assessment; policy specifies indications and frequency limits (total allowed per pregnancy).

Frequency limits revised over timeRevision history documents evolving TVU frequency limits, including allowance up to 13 TVUs per pregnancy and special rules for increased surveillance with shortened cervix.

Policy updates affect practiceRevisions include clarified wording (e.g., '<= 25 mm' threshold) and adjustments to schedules (weekly surveillance for 26–29 mm), demonstrating the policy's evolving approach to TVU indications and frequency.

First Detailed Fetal Ultrasound — Diagnosis Codes (Table 4, updated Oct 2023)

First detailed fetal ultrasound—diagnosis supportTable 4 lists diagnosis codes and code ranges that support medical necessity for the first detailed fetal ultrasound; Table 4 was updated in Oct 2023 to add multiple codes and ranges.

Updated code examplesRevision 10/23 added codes and ranges such as A92.5; D56.0–D56.9; D57.00–D57.819; M32.0–M32.9; N18.9; and multiple O00/O35 ranges to Table 4.

Usage requirement76811 must be billed with an appropriate high-risk diagnosis code from Table 4 to demonstrate medical necessity for the first detailed fetal ultrasound.

Detailed Obstetric Ultrasound — Practice Parameters and References

Practice parameter referencesDetailed obstetric ultrasound practice parameters referenced include AIUM, ACR, and ACOG guidance (AIUM-ACR-ACOG practice parameters and related ACOG practice bulletins).

Key guideline citationsPolicy references AIUM Practice Parameter for Detailed Second- and Third-Trimester Diagnostic Obstetric Ultrasound Examinations (2019) and ACOG practice bulletins addressing fetal growth and anomaly screening.

Clinical intentThe policy aligns the performance and expected components of detailed obstetric ultrasound with published society practice parameters to define appropriate indications and scope.

Background and Purpose

Ultrasound is the primary imaging tool in pregnancy to determine gestational age, fetal number, viability, and placental location. The policy references evidence that routine screening ultrasound in low-risk populations has not demonstrated improved perinatal outcomes, and therefore ultrasound use is most appropriate when targeted to specific clinical questions such as dating, growth assessment, anomaly evaluation, or evaluation of complications (for example placenta previa or cervical length assessment). Transvaginal ultrasound is identified for first-trimester indications and later for cervical length and placenta assessment, with explicit frequency guidance where indicated.