Accurate endometrial biopsy billing and coding begins with accurate physician documentation and the proper diagnosis. . Coding errors lead to claim denials, delays in payments, assessments of medical necessity and compliance issues for OB/GYN practices.
The code for the endometrial biopsy is the primary endometrial biopsy code: CPT 58100. It is used to obtain samples of the endometrium without the need of cervical dilatation. But the right code is what the supplier did and therefore coders need to look closely at the procedure note.
This 2026 CPT medical billing guide covers CPT 58100 billing standards, ICD-10-CM codes, medical necessity, documentation requirements, modifiers, pathology billing, frequent coding errors, and practical claim examples.
What Is an Endometrial Biopsy?
Endometrial biopsy — A diagnostic test in which a small sample of tissue is taken from the lining of the uterus.
Usually, the specimen is submitted for pathology to look for any abnormality in the endometrium which would explain the patient’s symptoms or clinical findings.
Common reasons for an endometrial biopsy are:
- Uterine hemorrhage, abnormal
- Heavy or irregular bleeding throughout periods Postmenopausal bleeding
- Abnormal endometrial findings on imaging
- Suspected endometrial hyperplasia
- Evaluation of an endometrial polyp
- Investigation of possible endometrial malignancy
For coders, the important point is that the clinical indication and the procedure performed are separate coding questions.
The diagnosis explains why the biopsy was performed. The CPT code explains what service the provider performed.
Endometrial Biopsy CPT Code 58100
The main CPT code for endometrial sample that is done without cervical dilatation is CPT 58100.
This code includes endometrial sampling by any method, and may include endocervical sample when conducted as part of this service. AAPC’s present CPT reference states that 58100 is for sampling tissue from the lining of the uterus without dilating the cervix.
When is procedure code CPT 58100 used?
Before reporting CPT 58100 endometrial biopsy, be sure that the documentation supports:
- Endometrial tissue sampling
- No cervical dilation
- A documented clinical indication
- Medical necessity
- A procedure that matches the CPT description
The sampling device itself generally does not determine a different CPT code when the service otherwise meets 58100.
A useful coding question is:
Did the provider get endometrial tissue without dilating the cervix?
If so, 58100 may be suitable.
Stop and study documentation before assigning 58100 if the cervix was dilated or another operational procedure was undertaken.
CPT 58100 vs Other Endometrial Procedure Codes
This is where many OB/GYN coding errors occur. Several procedures can produce an endometrial tissue specimen, but they are not necessarily reported with the same CPT code.
| CPT | General application |
| 58100 | Endometrial sampling without cervical dilation |
| 58110 | Add-on endometrial biopsy performed with qualifying colposcopy |
| 58120 | Nonobstetrical dilation and curettage |
| 58555 | Diagnostic hysteroscopy when separately reportable |
| 58558 | Surgical hysteroscopy with endometrial sampling and/or polypectomy when the complete code definition is met |
| 88305 | Applicable surgical pathology examination of a qualifying specimen |
CPT 58110 is an add-on procedure used when endometrial biopsy is performed during the same session as colposcopy; it is not simply a replacement for 58100.
CPT 58100 vs CPT 58120
The difference between 58100 and 58120 is really critical.
CPT 58100 is sampling without dilatation of the cervix.
CPT 58120 is for diagnostic and/or therapeutic nonobstetrical dilatation and curettage.
For example, if a physician seeks to do an endometrial biopsy and is unable to pass the tool due to cervical stenosis. Then the provider dilates the cervix and does a curettage to get the tissue.That is no longer a straightforward 58100 service.
Current 2026 coding guidance specifically addresses this scenario and directs reporting of 58120 when cervical stenosis obstructs passage of the sampling instrument and cervical dilation is necessary to access the uterine cavity.
Coding takeaway
Do not choose the CPT code based only on the physician’s original plan.
Code the procedure that was actually performed.
CPT 58100 vs Hysteroscopy
Hysteroscopic procedures require another coding review.
If the physician performs surgical hysteroscopy with endometrial sample or polypectomy, CPT 58558 may be applicable when the entire code definition applies.
Report 58100 only if endometrial tissue was obtained at the time of hysteroscopy.
The operative note should tell the coder whether the physician performed:
- Simple endometrial sampling
- Dilation and curettage
- Diagnostic hysteroscopy
- Surgical hysteroscopy
- Hysteroscopic sampling
- Hysteroscopic polypectomy
CMS’s 2026 NCCI policy resources should also be reviewed when multiple procedures are reported during the same encounter. CMS states that NCCI policies are intended to promote correct coding and prevent inappropriate unbundling.
ICD-10-CM Codes for Endometrial Biopsy
CPT identifies the procedure. ICD-10-CM diagnosis coding explains the condition or symptom supporting the service.
There is no single ICD-10-CM code that applies to every endometrial biopsy.
The diagnosis must come from the provider’s documentation.
Common ICD-10-CM Diagnosis Codes
| ICD-10-CM | Description | When it may apply |
| N92.0 | Excessive and frequent menstruation with regular cycle | Documented heavy/frequent regular-cycle bleeding |
| N92.1 | Excessive and frequent menstruation with irregular cycle | Documented excessive/frequent irregular-cycle bleeding |
| N92.4 | Excessive bleeding in the premenopausal period | Documented excessive premenopausal bleeding |
| N92.6 | Irregular menstruation, unspecified | Irregular menstruation without greater specificity |
| N93.8 | Other specified abnormal uterine and vaginal bleeding | Specified abnormal bleeding not better classified elsewhere |
| N93.9 | Abnormal uterine and vaginal bleeding, unspecified | Documentation remains nonspecific |
| N95.0 | Postmenopausal bleeding | Documented bleeding after menopause |
| N84.0 | Polyp of corpus uteri | Documented uterine/endometrial polyp |
| N85.00 | Endometrial hyperplasia, unspecified | Established unspecified hyperplasia |
| N85.01 | Benign endometrial hyperplasia | Established benign hyperplasia |
| N85.02 | Endometrial intraepithelial neoplasia | Established EIN |
| N88.2 | Cervical stenosis | Documented cervical stenosis relevant to the procedure |
| R93.89 | Abnormal findings on diagnostic imaging of other specified body structures | Applicable abnormal imaging finding |
| C54.1 | Malignant neoplasm of endometrium | Established endometrial cancer |
The CDC’s ICD-10-CM resources provide the official code set, Tabular List, Index, and applicable coding guidance for the date of service.
Endometrial Biopsy for Abnormal Uterine Bleeding
Abnormal uterine bleeding is one of the most common indications for endometrial sampling.
The provider may document:
- Heavy menstrual bleeding
- Frequent menstrual bleeding
- Irregular cycles
- Intermenstrual bleeding
- Other abnormal uterine bleeding
The diagnosis should be as specific as the documentation allows.
For example, if the provider documents excessive and frequent menstruation with a regular cycle, N92.0 may be appropriate.
If the record simply states “abnormal uterine bleeding” without additional detail, N93.9 may be appropriate.
The coder should not guess the menstrual pattern.
That is an important part of accurate endometrial biopsy billing and coding.
Endometrial Biopsy for Postmenopausal Bleeding
N95.0 — Postmenopausal bleeding is an essential diagnosis in claims for endometrial biopsies.
If the physician performs an endometrial biopsy without dilating the cervix, and the medical record notes postmenopausal hemorrhage, the claim may be coded as follows:
CPT 58100 + ICD-10-CM N95.0
The documentation should establish that the patient is postmenopausal and that bleeding occurred after menopause.
The diagnosis should not be assigned merely because the patient is older.
The chart should support the actual condition.
Endometrial Biopsy for Thickened Endometrium
Providers often perform endometrial sampling after an abnormal ultrasound or other imaging study.
One coding challenge is that “thickened endometrium” does not automatically mean the patient has endometrial hyperplasia.
If the provider documents an abnormal imaging finding without establishing a definitive disease, an appropriate abnormal-imaging code may be considered.
R93.89 may apply if documentation supports an abnormal finding on diagnostic imaging of another designated body structure.
However, if the physician does document a true diagnosis of endometrial hyperplasia, use the appropriate hyperplasia code.
Important rule
Do not turn an imaging finding into a disease diagnosis without provider documentation.
That distinction is important for both compliance and accurate ICD-10 coding for endometrial biopsy.
Medical Necessity for CPT 58100
A correctly selected CPT code does not guarantee payment.
The claim also needs a diagnosis and documentation that support medical necessity.
A good medical record should answer three questions:
- What problem did the patient have?
- Why did the provider believe an endometrial biopsy was necessary?
- What procedure was actually performed?
For example:
Patient presents with persistent postmenopausal bleeding. Prior evaluation demonstrates an abnormal endometrial finding. Endometrial sampling recommended for further evaluation. Endometrial biopsy performed without cervical dilation and specimen submitted to pathology.
Documentation like this gives the coder and payer a much clearer clinical picture than:
“EMB performed.”
The diagnosis should never be selected simply because it is likely to produce reimbursement.
Documentation Requirements for Endometrial Biopsy Billing
Good documentation makes endometrial biopsy claim submission much easier.
The procedure note should clearly identify the service performed.
Important documentation elements
- Indication
Explain why the biopsy was performed.
- Consent
Document consent according to the provider’s clinical and organizational requirements.
- Procedure
Describe the actual sampling procedure.
- Cervical dilation
For 58100, documentation should support that cervical dilation was not performed.
- Specimen
Document that endometrial tissue was obtained and handled appropriately for pathology when applicable.
- Patient response
Document tolerance, complications, and follow-up instructions as appropriate.
The more clearly the procedure note describes the actual service, the less likely the coder is to make assumptions.
Modifier 25 and CPT 58100
Modifier 25 can become relevant when an E/M service is performed on the same date as the biopsy.
For example, a patient presents with abnormal bleeding. The physician performs a separately identifiable evaluation, reviews the clinical history, assesses the condition, develops a treatment plan, and then performs the biopsy.
If the E/M service meets the applicable requirements, modifier 25 may be reported with the E/M code.
However, modifier 25 should not be added automatically whenever an office visit and biopsy occur on the same day.
The documentation must support a significant, separately identifiable E/M service beyond the work normally associated with the procedure.
Modifier 59 and Endometrial Biopsy
Modifier 59 is used to identify a distinct procedural service when the applicable coding requirements are met.
It should not be treated as a general-purpose denial override.
Before adding modifier 59, the coder should ask:
- Are two distinct procedures actually being performed?
- Is there an applicable NCCI edit?
- Does the edit permit a modifier?
- Does the documentation support the distinction?
- Is another modifier more appropriate?
CMS’s 2026 NCCI policy manual is an important reference for these situations.
Pathology Billing for an Endometrial Biopsy
The physician’s biopsy service and the pathology examination are separate billing concepts.
The physician performs the tissue acquisition.
A pathology provider or laboratory may separately report the appropriate pathology service when it performs the examination and the billing arrangement permits separate reporting.
A commonly encountered surgical pathology code is 88305, but the exact pathology code depends on the specimen and services actually performed.
Therefore, a claim should not automatically use the same code for both services.
Think of it as:
Physician obtains tissue → CPT 58100
Pathology provider examines tissue → Applicable pathology CPT
The billing entity, place of service, payer arrangement, and pathology services performed should also be considered.
Common Endometrial Biopsy Coding Errors
-
Using 58100 for Every Endometrial Biopsy
Not every procedure called an “endometrial biopsy” should automatically be coded 58100.
Check whether cervical dilation, D&C, hysteroscopy, or colposcopy changed the coding.
-
Coding Cancer Before It Is Diagnosed
A biopsy performed to investigate possible cancer does not automatically establish cancer.
Use the diagnosis supported by the documentation and applicable outpatient coding guidelines.
-
Using Hyperplasia for a Thickened Endometrium
A thickened endometrium on imaging does not automatically establish endometrial hyperplasia.
Code the documented finding or established diagnosis.
-
Adding Modifier 25 Automatically
Modifier 25 requires a separately identifiable E/M service.
-
Using Modifier 59 to Force Payment
Modifier 59 should reflect a legitimate distinct service, not an attempt to bypass an edit.
-
Ignoring Cervical Dilation
This is one of the most important technical issues with 58100.
If cervical dilation was required and D&C was performed, review 58120. Current 2026 coding guidance specifically addresses this situation.
Endometrial Biopsy Billing Examples
Example 1: Postmenopausal Bleeding
Documentation:
Patient has documented postmenopausal bleeding. Physician performs endometrial sampling without cervical dilation.
Possible coding:
- CPT: 58100
- ICD-10-CM: N95.0
The diagnosis explains why the biopsy was medically necessary.
Example 2: Heavy Regular Menstrual Bleeding
Documentation:
Patient has excessive and frequent menstruation with a regular cycle. Endometrial biopsy is performed without cervical dilation.
Possible coding:
- CPT: 58100
- ICD-10-CM: N92.0
The diagnosis should match the provider’s actual documentation.
Example 3: Abnormal Imaging
Documentation:
Ultrasound demonstrates an abnormal endometrial finding. The physician performs endometrial sampling without cervical dilation.
Possible coding:
- CPT: 58100
- ICD-10-CM: R93.89, when the documentation supports that code
Do not automatically report hyperplasia unless the provider establishes that diagnosis.
Example 4: Cervical Stenosis
Documentation:
The sampling instrument cannot pass because of cervical stenosis. The provider dilates the cervix and performs curettage to obtain endometrial tissue.
Possible coding:
- CPT: 58120
- ICD-10-CM: N88.2 when supported by documentation
- Additional documented indication as appropriate
This is an important example because the procedure is no longer the uncomplicated 58100 service.
Example 5: Surgical Hysteroscopy
Documentation:
The physician performs surgical hysteroscopy with endometrial sampling and/or polypectomy.
Possible coding:
- CPT: 58558 when the full code definition is met
- Appropriate documented diagnosis
Review NCCI and CPT instructions before adding another biopsy code.
2026 Endometrial Biopsy Coding Checklist
Before submitting a claim, the coding team should verify:
- Endometrial sampling was actually performed.
- The indication is documented.
- Medical necessity is supported.
- Cervical dilation was not performed for a 58100 service.
- The correct CPT code was selected.
- D&C was considered when appropriate.
- Hysteroscopy was considered when performed.
- The ICD-10-CM diagnosis matches provider documentation.
- A suspected condition was not incorrectly coded as confirmed.
- Modifier 25 is supported if used.
- Modifier 59 is supported if used.
- Current NCCI guidance has been checked when applicable.
- Pathology billing is handled separately when appropriate.
- Payer-specific requirements have been reviewed.
- The ICD-10-CM code is valid for the date of service.
Final Thoughts
The endometrial biopsy CPT code 58100 is straightforward when the documentation supports endometrial sampling without cervical dilation. The harder part is making sure the entire claim is consistent: the procedure, diagnosis, documentation, modifiers, pathology services, and payer requirements all need to align.
For effective endometrial biopsy billing and coding, start with the provider’s procedure note. Confirm exactly what happened, determine the appropriate CPT code, then select the most specific documented ICD-10-CM diagnosis.
Remember the key distinction:
58100 = endometrial sampling without cervical dilation.
When the procedure changes, the code may change too. Cervical dilation with D&C may point to 58120, while qualifying hysteroscopic procedures require review of the appropriate hysteroscopy code.
For 2026 claims, always verify the code set applicable to the date of service, current CPT guidance, ICD-10-CM Official Guidelines, CMS NCCI policies, and individual payer requirements. CMS’s 2026 Medicare NCCI Policy Manual became effective January 1, 2026, while CDC/NCHS provides the applicable 2026 ICD-10-CM releases.
Frequently Asked Questions
What is the endometrial biopsy CPT code for 2026?
The primary endometrial biopsy CPT code is 58100 for endometrial sampling performed without cervical dilation.
What ICD-10 code is used with CPT 58100?
There is no single diagnosis code for every biopsy. Common examples include N95.0 for postmenopausal bleeding, N92-series codes for certain menstrual bleeding conditions, N93-series codes for abnormal uterine/vaginal bleeding, and appropriate codes for documented endometrial abnormalities.
What is the CPT code when cervical dilation is required?
When cervical stenosis or another circumstance requires cervical dilation and the physician performs D&C, 58120 should be reviewed rather than automatically reporting 58100.
Can 58100 be billed with pathology code 88305?
The biopsy procedure and pathology examination are separate services. When a pathology provider performs a separately reportable examination of the specimen, the appropriate pathology code may be billed according to the services performed and payer requirements.
Can CPT 58100 be billed with an E/M code?
A same-day E/M may be separately reportable when it meets the applicable requirements. Modifier 25 may be appropriate when the E/M is significant and separately identifiable.
What is the ICD-10 code for postmenopausal bleeding?
N95.0 — Postmenopausal bleeding.
What is the ICD-10 code for endometrial hyperplasia?
Depending on the documented condition, relevant 2026 codes include N85.00, N85.01, and N85.02. The provider’s specific diagnosis determines the appropriate code.
What is the ICD-10 code for endometrial cancer?
C54.1 — Malignant neoplasm of endometrium, when the malignancy is established and documented. Do not use a confirmed cancer code merely because the biopsy is being performed to investigate possible cancer.