Accurate obstetric coding depends on more than identifying that fetal monitoring took place. Billing teams need to understand why fetal surveillance was ordered, what type of test was performed, how many fetuses were evaluated, and whether another fetal surveillance service already includes the nonstress test.
CPT code 59025 is used to report a fetal nonstress test, commonly called an NST. The test evaluates fetal heart rate in relation to fetal movement and is commonly used as part of antepartum fetal surveillance when additional assessment of fetal well-being is clinically appropriate.
The American Medical Association lists CPT 59025 as a fetal nonstress test within its antepartum procedure section.
Although the code appears straightforward, billing can become more complicated when the patient is carrying twins, testing is repeated on the same day, a biophysical profile is also performed, or the professional and technical components are provided by different entities.
Coding and payer requirements may also change. For a broader look at current coding developments, MedIntelHub provides an overview of annual CPT changes, documentation requirements, and payer considerations. 2026 CPT Code Changes: What Providers Need to Know
What Is CPT Code 59025?
CPT 59025 represents a fetal nonstress test performed during the antepartum period.
During an NST, fetal heart rate is monitored over time while fetal movement is observed. The purpose is to determine how the fetal heart rate responds to movement without intentionally creating uterine contractions or otherwise placing stress on the fetus.
ACOG explains that a nonstress test measures fetal heart rate in response to fetal movement. The test is generally performed while the patient is reclining or lying down, with a sensor placed around the abdomen to record fetal heart activity. Testing usually lasts at least 20 minutes.
This differs from a contraction stress test, which evaluates fetal heart rate while uterine contractions occur.
CPT 59025 Description and Purpose
The CPT 59025 description refers to fetal nonstress testing.
Its purpose is to provide information about fetal well-being during pregnancy. The term “nonstress” refers to the fact that nothing is intentionally done during the test to place stress on the fetus.
During the monitoring period, the healthcare professional evaluates fetal heart rate patterns and their relationship to fetal movement.
A reactive, or reassuring, result generally means that appropriate fetal heart rate accelerations were observed.
A nonreactive result means that enough expected accelerations were not detected during the testing period. A nonreactive NST does not automatically mean that the fetus is unhealthy. Depending on the circumstances, monitoring may continue or another fetal assessment may be performed.
The CPT code describes the service performed. It does not, by itself, establish medical necessity or guarantee insurance reimbursement.
When Is Procedure Code 59025 Used?
Procedure code 59025 may be used when an antepartum nonstress test is performed to assess fetal well-being.
ACOG notes that special fetal surveillance may be considered when there is an increased risk of pregnancy complications or stillbirth. Circumstances may include:
- Decreased fetal movement
- Fetal growth concerns
- Maternal high blood pressure
- Certain cases of diabetes
- Some pre-existing maternal medical conditions
- Rh sensitization
- Certain complicated multiple pregnancies
- Postterm pregnancy
- Other maternal or fetal conditions associated with increased risk
ACOG emphasizes that surveillance decisions should be individualized according to the patient’s condition and risk rather than automatically applied to every pregnancy.
The diagnosis reported with CPT 59025 should accurately reflect the documented clinical reason for surveillance.
When Is a Fetal Nonstress Test Performed?
There is no single gestational age that applies to every patient.
ACOG’s patient guidance states that special fetal testing commonly begins between 32 and 34 weeks, although it may begin earlier when problems are particularly serious or when multiple risk factors are present. More detailed ACOG guidance also recommends individualizing the timing according to the specific maternal or fetal condition.
Testing frequency also varies.
Some patients may undergo surveillance weekly, while others may require testing twice weekly or at another interval based on their condition, previous results, and changes in clinical status. ACOG notes that the optimal frequency has not been established for every condition.
Billing teams should therefore avoid assuming that one diagnosis automatically supports a fixed number of NSTs.
How Does a Nonstress Test Work?
During a typical NST, an external sensor is placed around the patient’s abdomen to monitor fetal heart rate.
The fetal heart rate is recorded over time and evaluated in relation to fetal movement.
ACOG notes that testing usually lasts at least 20 minutes. If an adequate reassuring pattern is not initially observed, testing may continue longer or additional assessment may be considered.
For coding purposes, the record should support an actual nonstress test with interpretation, not merely a routine fetal heart rate check.
Billing Guidelines for CPT Code 59025
Correct billing for CPT code 59025 involves more than entering the code on a claim.
Before submitting the service, the billing team should determine:
- Why the NST was ordered
- Whether medical necessity is documented
- Whether one fetus or multiple fetuses were evaluated
- Whether the NST was repeated on the same date
- Whether a biophysical profile was also performed
- Who provided the technical component
- Who interpreted and reported the test
- Whether modifiers are appropriate
- Whether the payer has specific maternity or fetal-surveillance rules
Coverage requirements can differ considerably among insurers.
For example, Aetna’s current antepartum fetal-surveillance policy lists CPT 59025 among the covered codes when its medical-necessity criteria are satisfied.
Aetna Antepartum Fetal Surveillance Policy
A valid CPT code should therefore never be treated as an automatic guarantee of payment.
CPT 59025 and Medical Necessity
A fetal nonstress test should have a documented clinical reason.
A general statement such as “pregnant patient” may not sufficiently explain why additional fetal surveillance was required.
Instead, documentation may identify a specific reason such as decreased fetal movement, hypertension, fetal growth concerns, diabetes, a complicated multiple pregnancy, or another medically supported condition.
ACOG recommends considering patient-specific factors when determining when and how often antepartum fetal surveillance should be performed.
Medical necessity, CPT coding, and payer coverage are closely related but remain separate issues.
MedIntelHub makes the same distinction in its discussion of current CPT updates: selecting a valid CPT code does not automatically establish payer coverage or reimbursement.
Read MedIntelHub’s 2026 CPT Coding Guide
Professional and Technical Components of CPT 59025
CPT 59025 may involve both a professional component and a technical component, depending on where the test is performed and which entity provides each part of the service.
The technical portion generally involves the equipment, staff, and production of the fetal heart rate tracing.
The professional component generally involves interpretation and reporting by the physician or other qualified healthcare professional.
A typical reporting arrangement may look like this:
| Billing Situation | Typical Reporting |
|---|---|
| Practice provides both testing and interpretation | 59025 |
| Physician provides only the professional interpretation | 59025-26 |
| Entity provides only the technical component | 59025-TC |
The exact approach should be verified with the payer and the applicable fee schedule.
CMS’s Physician Fee Schedule Lookup Tool provides Medicare pricing, RVUs, and payment-policy information and can be used to review whether particular modifiers and payment rules apply.
CMS Physician Fee Schedule Lookup
CPT 59025 and Twin Pregnancies
Multiple gestation creates additional billing considerations because more than one fetus may require separate monitoring and interpretation.
Documentation should clearly establish which fetuses were evaluated.
However, the method used to report the additional fetus can vary by payer.
For example, UnitedHealthcare’s 2026 commercial obstetrical reimbursement policy instructs providers to report CPT 59025 for the first fetus and a separate CPT 59025 with modifier 59 for the initial NST of the second fetus in a twin pregnancy.
UnitedHealthcare Obstetrical Reimbursement Policy
This should not be interpreted as a universal rule for every insurer.
Other payers may use different claim-formatting or units-of-service requirements. Practices should verify the patient’s specific plan before billing multiple fetal NSTs.
What If the NST Is Repeated on the Same Day?
An NST may occasionally need to be repeated later on the same date.
When a genuinely separate repeat test is performed, a repeat-procedure modifier may be appropriate.
For example, UnitedHealthcare’s current commercial policy instructs providers to use:
- Modifier 76 when the same physician repeats the NST
- Modifier 77 when another physician repeats the NST
The policy also provides additional instructions when repeat testing involves twin gestations.
These are payer-specific billing instructions and should not automatically be applied to every insurer.
Documentation should clearly demonstrate that a separate repeat NST was actually performed.
CPT 59025 vs. Biophysical Profile Codes
One of the most important areas of fetal-surveillance coding is distinguishing a nonstress test from a biophysical profile, commonly called a BPP.
A BPP assesses several measures of fetal well-being and combines fetal heart-rate assessment with ultrasound evaluation.
| Code | General Service |
|---|---|
| 59020 | Fetal contraction stress test |
| 59025 | Fetal nonstress test |
| 76818 | Fetal biophysical profile with NST |
| 76819 | Fetal biophysical profile without NST |
| 76815 | Limited obstetric ultrasound |
CMS materials distinguish CPT 76818 as a fetal biophysical profile with NST and CPT 76819 as a fetal biophysical profile without NST.
These descriptions are simplified for educational comparison. Final coding decisions should be made using the current licensed CPT codebook.
Can CPT 59025 Be Billed With 76818?
Generally, CPT 59025 should not be separately reported for the same fetal biophysical profile represented by CPT 76818.
CPT 76818 already incorporates the nonstress-test component into the biophysical profile. AMA materials describing the development of the BPP code also identify the NST as part of the 76818 service.
Reporting CPT 59025 separately for the same NST already represented by 76818 could result in duplicate billing.
Can CPT 59025 Be Billed With 76819?
CPT 76819 represents a fetal biophysical profile without a nonstress test.
The coding relationship is therefore different from CPT 76818.
When a separately performed, medically necessary NST is documented in addition to a BPP that does not include the NST, CPT 59025 may potentially be reportable, subject to current CPT instructions, NCCI edits, and payer policy.
Documentation should clearly establish which services were actually performed.
CPT 59025 vs. Contraction Stress Test
CPT 59025 should not be confused with CPT 59020, which represents a fetal contraction stress test.
A nonstress test evaluates fetal heart rate in relation to fetal movement without intentionally producing uterine contractions.
A contraction stress test evaluates how the fetal heart rate responds while uterine contractions occur.
ACOG identifies the NST and contraction stress test as separate fetal-surveillance procedures.
The actual test performed—not merely the reason for fetal surveillance—should determine the procedure code.
Is CPT 59025 Used for Routine Labor Monitoring?
CPT 59025 is an antepartum fetal nonstress-test code. AMA guidance lists it within the antepartum procedures section.
It should not automatically be assigned to routine fetal heart-rate monitoring performed as part of labor management.
Antepartum NST testing and fetal monitoring during labor occur in different clinical contexts.
Coders should review the patient’s status, reason for monitoring, and provider documentation rather than assigning 59025 whenever a fetal heart tracing appears in the medical record.
Documentation Requirements for CPT 59025
Strong documentation supports both the service performed and its medical necessity.
A complete NST record should generally identify:
- Reason the test was ordered
- Gestational age
- Number of fetuses evaluated
- Relevant maternal or fetal condition
- Duration of monitoring
- Fetal heart-rate findings
- Fetal movement when applicable
- Important tracing findings
- Whether the test was reactive or nonreactive
- Professional interpretation
- Follow-up plan when appropriate
- Identity of the healthcare professional interpreting the study
For twins or other multifetal pregnancies, documentation should allow the findings for each fetus to be distinguished.
The record should support an actual NST with interpretation rather than simply documenting that the patient was connected to a fetal monitor.
Common CPT 59025 Billing Mistakes
1. Billing 59025 Without a Documented Clinical Indication
The medical record should explain why fetal surveillance was necessary.
The diagnosis should match the actual condition or clinical concern documented by the healthcare professional.
2. Reporting 59025 With CPT 76818 for the Same NST
CPT 76818 already includes the nonstress-test component.
Separately reporting 59025 for the same BPP can create duplicate billing.
3. Applying One Twin-Billing Method to Every Payer
UnitedHealthcare, for example, provides specific instructions involving modifier 59 for the second fetus, but other insurers may have different rules.
Always verify the applicable payer policy.
4. Automatically Billing Multiple Units
A longer monitoring period or multiple fetal tracings does not automatically justify multiple units of CPT 59025.
A separately reportable repeat service should be supported by the medical record and payer requirements.
5. Misusing Modifier 59
Modifier 59 should not be added simply to bypass an edit.
If a payer specifically instructs its use for an additional fetus, the claim and documentation should satisfy that payer’s policy.
6. Incorrect Professional and Technical Component Billing
When one entity provides the equipment and another healthcare professional provides only the interpretation, global billing may not be appropriate.
The billing arrangement should reflect the actual services provided.
7. Confusing NST With Routine Labor Monitoring
CPT 59025 should represent a true antepartum fetal nonstress test, not routine fetal monitoring associated with ordinary labor management.
8. Assuming Correct Coding Guarantees Payment
A valid CPT code does not guarantee reimbursement.
Payers may separately apply medical-necessity criteria, diagnosis requirements, frequency limits, authorization rules, benefit restrictions, and other claim edits.
Tips for Accurate CPT 59025 Billing
Before submitting a claim involving CPT 59025:
- Confirm that a true fetal nonstress test was performed.
- Review the documented clinical indication.
- Confirm gestational age when relevant.
- Determine how many fetuses were evaluated.
- Check whether testing was repeated on the same date.
- Determine whether another reported service already includes the NST.
- Pay particular attention to CPT 76818.
- Determine who provided the technical and professional components.
- Use modifiers only when supported.
- Review payer requirements for twin or multifetal pregnancies.
- Verify coverage and frequency requirements.
- Use the current CPT code set and current payer guidance.
A consistent review process can reduce duplicate billing, modifier errors, medical-necessity denials, and incorrect fetal-surveillance claims.
2027 Maternity Coding Changes: What Practices Should Know
Obstetric practices should also be preparing for a major change to maternity-care coding.
The AMA has approved a substantial restructuring of maternity-care CPT reporting that will become effective January 1, 2027. The current global maternity framework will move toward more granular reporting of antepartum care, labor management, delivery, and postpartum care.
The change does not take effect during 2026, so practices should not apply the new maternity-care framework prematurely.
Importantly, the AMA’s early 2027 maternity guidance continues to list 59025 as the fetal nonstress-test code.
AMA: CPT 2027 Maternity Care Services Code Changes
Organizations should use the final 2027 CPT codebook and applicable payer guidance when those changes become effective.
Frequently Asked Questions
What does CPT code 59025 mean?
CPT code 59025 represents a fetal nonstress test performed as part of antepartum fetal assessment.
The test monitors fetal heart rate in relation to fetal movement.
What is CPT 59025 used for?
CPT 59025 is used to report a fetal nonstress test when additional assessment of fetal well-being is clinically appropriate.
Is CPT 59025 an ultrasound?
No.
A nonstress test primarily uses fetal heart-rate monitoring. Ultrasound may be performed separately or as part of a fetal biophysical profile.
How long does a fetal nonstress test take?
ACOG states that an NST usually lasts at least 20 minutes. Monitoring can continue longer when an adequate result is not initially obtained.
What does a reactive NST mean?
A reactive NST generally means that appropriate fetal heart-rate accelerations occurred during the monitoring period and is considered reassuring at that time.
What does a nonreactive NST mean?
A nonreactive NST means that enough expected fetal heart-rate accelerations were not observed.
It does not automatically mean that the fetus is unhealthy. Additional monitoring or testing may be required.
Can CPT 59025 be billed with CPT 76818?
Generally not for the same BPP because CPT 76818 already includes the NST component.
Can CPT 59025 be billed with CPT 76819?
Potentially.
CPT 76819 represents a BPP without an NST. A separately performed and medically necessary NST may potentially be reportable when documentation, CPT instructions, coding edits, and payer policy support it.
Can CPT 59025 be reported for twins?
Yes, separate fetal testing may require additional reporting when each fetus is independently monitored.
The billing method is payer-specific. UnitedHealthcare’s 2026 commercial policy, for example, instructs providers to use 59025 for the first fetus and 59025 with modifier 59 for the second fetus.
Can modifier 26 be used with CPT 59025?
Modifier 26 may be appropriate when only the professional component—the interpretation and report—is being billed.
Providers should verify component billing and modifier requirements with the applicable payer and current fee schedule.
Is CPT 59025 always covered by insurance?
No.
Coverage depends on the patient’s condition, medical necessity, benefits, frequency requirements, documentation, and individual payer policy.
Conclusion
Understanding CPT code 59025 involves more than knowing that it represents a fetal nonstress test.
The medical record should establish why antepartum fetal surveillance was needed, how many fetuses were evaluated, what the test showed, and who provided and interpreted the service.
Billing teams also need to distinguish CPT 59025 from related fetal-surveillance procedures. In particular, CPT 76818 already includes an NST, while CPT 76819 represents a biophysical profile without the NST.
Twin pregnancies and repeat testing introduce additional billing considerations. Modifiers such as 59, 76, or 77 may be appropriate under certain payer policies, but they should not be applied universally without reviewing the applicable insurer’s instructions.
Accurate reimbursement begins with clear documentation, correct code selection, appropriate professional and technical component billing, and verification of payer-specific coverage requirements.
Resources
American College of Obstetricians and Gynecologists — Special Tests for Monitoring Fetal Well-Being
ACOG explains nonstress testing, biophysical profiles, contraction stress testing, timing, and general interpretation of fetal-surveillance results.
ACOG: Special Tests for Monitoring Fetal Well-Being
ACOG — Indications for Outpatient Antenatal Fetal Surveillance
This guidance discusses maternal and fetal risk factors, timing, and frequency considerations for outpatient antenatal fetal surveillance.
ACOG: Indications for Outpatient Antenatal Fetal Surveillance
Centers for Medicare & Medicaid Services — Physician Fee Schedule
CMS provides Medicare pricing, RVUs, modifier information, and other payment-policy data.
CMS Physician Fee Schedule Lookup
Aetna — Antepartum Fetal Surveillance
Aetna’s current medical policy includes CPT 59025 among fetal-surveillance services covered when applicable selection criteria are met.
Aetna Antepartum Fetal Surveillance Policy
UnitedHealthcare — Obstetrical Reimbursement Policy
UnitedHealthcare’s current commercial policy includes specific instructions for repeat NSTs and NST reporting in twin gestations.
UnitedHealthcare Obstetrical Policy
American Medical Association — 2027 Maternity Care Coding Changes
The AMA explains the maternity-care CPT restructuring scheduled to take effect January 1, 2027.
AMA: CPT 2027 Maternity Care Services Code Changes
MedIntelHub — 2026 CPT Code Changes
For additional information about current CPT revisions, documentation, payer policies, and reimbursement considerations:
2026 CPT Code Changes: What Providers Need to Know
MedIntelHub — Editorial Policy
Readers can review MedIntelHub’s standards for healthcare sourcing, accuracy, transparency, updates, and editorial limitations.
Editorial Disclaimer
This article is provided for educational and informational purposes only. CPT coding requirements, clinical guidelines, CMS policies, payer rules, modifier requirements, reimbursement policies, and documentation standards can change and may vary by payer, jurisdiction, provider type, place of service, and individual circumstances.
CPT is a registered trademark of the American Medical Association.
This article does not replace the current licensed CPT codebook, official CPT instructions, ACOG clinical guidance, CMS requirements, Medicare Administrative Contractor policies, commercial payer guidance, or advice from a qualified medical coding, compliance, or healthcare professional.
Healthcare organizations should verify current coding, billing, documentation, and coverage requirements before submitting claims.
David Bennett
David Bennett is an author at MedIntelHub, where he creates clear, practical, and well-researched content about healthcare, medical billing, insurance, and patient education. His goal is to make complex healthcare topics easier for readers to understand and use in everyday situations. David emphasizes accuracy, transparency, and reliable sourcing, using information from trusted organizations and official healthcare resources whenever possible. Content published by David is intended for educational purposes and should not replace advice from qualified medical, legal, or healthcare professionals.