CPT® Code 58100

Last Updated: February 2026 | Verified for 2026 AMA, CPT & CMS Guidelines

Quick Reference:

• What 58100 means: CPT 58100 describes endometrial sampling (biopsy) with or without endocervical sampling, performed without cervical dilation, by any method (e.g., Pipelle). It is a diagnostic sampling service; pathology is billed separately.
• Most common medical-necessity use: Evaluation of abnormal uterine bleeding (AUB)—including postmenopausal bleeding—and assessment for endometrial hyperplasia or malignancy risk, consistent with major clinical guidance summarized in primary-care and payer policy resources.
• Key boundary (dilation changes the code): If cervical dilation is required to obtain the sample, CPT 58100 is generally not the correct code; coding guidance highlights that dilation-supported sampling should be reported using the appropriate dilation/D&C pathway when performed.
• Bundling and edit risk: National Correct Coding Initiative (NCCI) policy governs when certain gynecologic procedures are considered integral or “scout/preparatory” services and therefore not separately billable. NCCI compliance is essential to avoid denials and post-payment recoupment.
• Modifier essentials: Modifier 25 may be appropriate on a same-day E/M only when a significant, separately identifiable evaluation occurs beyond routine pre-procedure work. Modifier 59 (or payer-accepted X-modifiers) should be reserved for truly distinct procedural services consistent with payer policy and documentation.
• Documentation must support “why” and “what”: Payers expect a clear indication (e.g., AUB pattern, postmenopausal bleeding, risk factors), procedure technique (no dilation), specimen handling, and follow-up plan; missing indication documentation is a common denial driver. CPT 58100 is a high-frequency diagnostic procedure in gynecology and primary care pathways for abnormal uterine bleeding.

Payment and audit risk typically does not arise from the sampling device used; it arises from

• coding 58100 when documentation suggests cervical dilation or a different procedural pathway,
• billing multiple services that are bundled or treated as “preparatory/scout” under NCCI policy, and
• billing an E/M visit on the same day without documentation that supports a separately identifiable evaluation. This 2026-focused guide aligns coding and documentation with payer-realistic review behavior using CMS policy and a small set of authoritative clinical and payer sources.

1. Clinical Definition and Procedure Scope (CPT 58100)

CPT 58100 is defined as: “Endometrial sampling (biopsy) with or without endocervical sampling (biopsy), without cervical dilation, any method.” The code represents the sampling/administration procedure—not the pathology interpretation—and is commonly performed using suction-based devices (e.g., Pipelle) in an office or outpatient setting.

Operationally, a clean 58100 record has three defining elements:

• Target tissue: endometrium (± endocervical sampling, when performed and documented).
• Approach constraint: no cervical dilation is required to accomplish the sampling.
• Diagnostic purpose: evaluation of bleeding patterns, suspected hyperplasia, cancer exclusion, or other medically necessary diagnostic assessment. The service is typically paired with a pathology CPT code (e.g., surgical pathology) and an appropriate diagnosis code set that supports medical necessity (e.g., abnormal bleeding codes, postmenopausal bleeding). Payer review tends to focus on the indication narrative and whether the documented technique aligns with “without dilation.” A payer does not need to dispute the clinical value of the biopsy to deny a claim; a mismatch between documentation and code definition is sufficient for denial or recoding.

Practical boundary: If the record documents cervical dilation as necessary to obtain the sample (for example due to stenosis), the correct reporting pathway is typically not 58100. Coding guidance emphasizes that dilation-supported sampling should be coded using the appropriate alternative procedure code(s) and that the reason for dilation should be documented.

2. Medical Necessity: Indications and Risk-Based Use

For claim defensibility, the key medical-necessity concept is that endometrial biopsy is generally performed to evaluate bleeding or risk contexts where endometrial pathology must be ruled out or characterized. Two practical anchors for “what payers expect” are (a) widely used clinical guidance summaries, and (b) payer clinical policy bulletins that operationalize coverage criteria.

2.1 Abnormal uterine bleeding (AUB) and postmenopausal bleeding

Abnormal uterine bleeding is the most frequent driver of 58100 utilization. AAFP’s clinical review emphasizes risk-based decision-making: age, bleeding pattern, and risk factors shape when biopsy is indicated and how it is integrated with ultrasound and medical management.

In postmenopausal bleeding pathways, documentation should clearly establish why biopsy is the next step (e.g., persistent bleeding, recurrent episodes, abnormal ultrasound findings, or high-risk profile). Commercial payer policies commonly align coverage with abnormal bleeding evaluation and risk-based surveillance frameworks.

2.2 Higher-risk profiles (hyperplasia/cancer risk)

Practical documentation in a payer environment often requires explicit mention of risk factors when they influence decision-making. AAFP’s summary highlights that risk factors and clinical context should be recorded (for example obesity, chronic anovulation/PCOS, medication exposures such as tamoxifen, or family/genetic risk). While the clinical management may be straightforward, payer review is claims-and-record driven; if risk factors are not documented, the record can read like low-value or routine screening, which increases denial risk.

Payer policy documents (e.g., a clinical policy bulletin) may explicitly list indications for endometrial sampling and also list situations where biopsy is considered not medically necessary or investigational. When a payer policy is used as the review framework, the chart should map clearly to a covered indication (e.g., abnormal bleeding evaluation, suspected endometrial pathology, or surveillance in a defined high-risk setting).

2.3 Avoiding “routine infertility workup” denials

A common denial pattern arises when endometrial biopsy is billed as part of a generic infertility evaluation without clear uterine pathology suspicion. Some payer infertility coverage policies limit coverage to defined clinical scenarios, and they may not support routine endometrial sampling unless specific findings or risks are present. If infertility is part of the clinical story, the note should still state the specific indication for biopsy (e.g., abnormal bleeding, ultrasound suspicion, suspected hyperplasia) rather than leaving the procedure to appear as routine screening.

3. Code Selection: 58100 vs Related Codes (58110, 58120, 58558)

Correct code selection is the single highest-yield compliance step. Most audit findings in this family arise from misunderstanding when 58100 is appropriate versus when a different procedure code describes what was actually done.

3.1 CPT 58100 (sampling without dilation)

Use 58100 when the clinician obtains an endometrial sample with or without endocervical sampling without cervical dilation and when the service is diagnostic sampling as documented.

3.2 CPT 58110 (sampling performed with another procedure)

Endometrial sampling may occur in conjunction with other gynecologic diagnostic services. When biopsy is performed at the time of another primary procedure, CPT rules often expect the appropriate “with other procedure” code selection pattern. In practice, the coding rationale should be supported by an operative note that clearly shows the primary service and the additional sampling service, including technique and medical necessity for each. (When payers review, they look for separate procedural intent rather than a single, bundled narrative.)

3.3 Dilation changes the coding pathway (58120 and related)

A decisive boundary is whether cervical dilation was required to obtain the sample. Coding guidance (including specialty coding resources) emphasizes that if dilation is performed to accomplish endometrial sampling, then reporting should reflect that procedural reality rather than forcing 58100. The documentation should explicitly state why dilation was necessary (e.g., stenosis) and what was performed.

3.4 Operative hysteroscopy sampling/polypectomy (58558)

When tissue sampling is performed as part of an operative hysteroscopy with endometrial sampling and/or polypectomy (with or without curettage), the hysteroscopic surgical code (e.g., 58558) is generally used rather than an office-based sampling code. This is particularly relevant when the record documents hysteroscopic visualization and operative removal or directed sampling in the uterine cavity. In a payer environment, the operative report drives the code choice.

3.5 Comparison table: common selection logic

4. Documentation Standards (Audit-Defensible)

Documentation must support two questions payers and auditors routinely ask:

(1) Was the biopsy medically necessary?

(2) Was 58100 the accurate descriptor of what was performed?

AAFP’s clinical review and payer clinical policy criteria provide practical anchors for what documentation elements are expected.

4.1 Minimum documentation elements for CPT 58100

• Indication (the “why”): Abnormal bleeding pattern, postmenopausal bleeding, ultrasound findings if relevant, and/or risk factors influencing the decision.
• Pregnancy status (when applicable): In reproductive-age patients, documentation commonly includes pregnancy exclusion as part of procedural safety workflows.
• Technique (the “what”): “Endometrial biopsy performed” with method and device, and explicit statement that dilation was not performed when relevant for audit clarity.
• Specimen handling: Specimen obtained and sent to pathology; note if inadequate sample and follow-up plan.
• Patient tolerance and complications: Analgesia/anesthesia used (if any), immediate complications (bleeding, vasovagal), and post-procedure instructions.
• Follow-up plan: How results will be communicated and next steps based on pathology.

4.2 Documentation to support “no dilation”

Because “without cervical dilation” is part of the code definition, the record should not be ambiguous. If cervical stenosis is present and dilation is performed, the reason should be documented and code selection should follow the performed service. Specialty coding guidance explicitly emphasizes documenting why dilation was needed and avoiding 58100 when dilation is performed to accomplish sampling.

4.3 Documentation that protects against “routine E/M + procedure” denials

When an E/M service is billed on the same day, payers often review whether the E/M was distinct from routine pre-procedure evaluation. AAFP’s guidance highlights practical pitfalls and supports the principle that routine counseling and basic assessment integrated into the procedure may not support a separate E/M. If a separate problem is evaluated or management decisions are made beyond the biopsy work (e.g., anemia workup, medication changes, differential diagnosis management), document it clearly.

5. Modifier Usage and Common Edit Scenarios

Modifier use must be documentation-driven. In this family, the most important modifiers are 25 (E/M separation) and 59 (distinct procedural service). NCCI policy is the practical boundary for when services are considered integral or bundled.

5.1 Modifier 25 (E/M on the same day)

Append -25 to the E/M code only when a significant, separately identifiable E/M service was performed in addition to the biopsy. Examples that often support 25 include:

• Evaluation and management of a new complaint requiring work-up beyond deciding to perform the biopsy.
• Complex counseling and management decisions (e.g., risk stratification, medication plan changes, referral decisions) separate from routine procedure consent and instructions. The note should show distinct assessment and plan elements that stand apart from routine pre-procedural work.

5.2 Modifier 59 (or payer-accepted X-modifiers)

Use -59 (or X-modifiers when accepted) to indicate a distinct procedural service when edit logic would otherwise bundle services. This should not be used as a “payment override.” NCCI policy provides the compliance framework for determining when services are separately reportable versus integral.

5.3 Other modifiers (use cautiously and payer-specifically)

• -52 (reduced services): Consider when the procedure is attempted but not completed or is significantly reduced; documentation should explain technical limitation and clinical circumstances.
• -51 (multiple procedures): May apply in some payer/facility contexts when multiple procedures are performed; follow payer instructions.
• -26 / -TC: Generally relevant to diagnostic tests with split professional/technical components; typically not central to 58100, but may appear in combined workflows. Common audit trigger: Modifier 59 used repeatedly on the same provider’s claims without strong documentation often triggers review. If procedures are not truly distinct by site, session, or clinical purpose, recoupment risk is high. NCCI policy is the appropriate reference baseline for bundled service logic.

6. Medicare, NCCI Policy, and Coverage Implementation

Medicare generally covers diagnostic procedures when they are reasonable and necessary. For 58100, the practical Medicare compliance framework is less about a single national “endometrial biopsy coverage” rule and more about: (a) correct CPT selection based on what was performed, (b) documentation supporting medical necessity, and (c) NCCI policy controlling bundling and “scout” procedure billing patterns.

6.1 NCCI policy: “scout,” preparatory, and integral services

NCCI policy addresses when certain procedures are considered integral to another service or when billing a procedure as a preparatory/scout service is inappropriate. In practice, this matters because gynecologic diagnostic pathways often involve multiple services on the same date (e.g., pelvic exam, ultrasound review, sampling, colposcopy, or other evaluation). When the claim indicates multiple related procedures, NCCI edits and the supporting documentation determine whether the services are separately reportable.

6.2 “What auditors check” in Medicare claims

• Technique-consistency: Documentation must align with “without dilation” for 58100.
• Medical necessity narrative: The record should show why sampling was clinically appropriate (AUB evaluation, postmenopausal bleeding, risk factors).
• Bundling logic: When multiple procedures appear, NCCI policy governs separate reporting.

7. Commercial Payer Policies and Practical Claim Expectations

Commercial payer coverage often mirrors widely accepted clinical pathways but operationalizes them through medical policy criteria and documentation demands. In practice, two payer-facing realities matter:

(1) policies frequently specify indications and exclusions, and

(2) documentation must map to those indications.

7.1 Example: Aetna clinical policy criteria

Aetna’s clinical policy bulletin on endometrial sampling is a high-visibility payer reference that commonly influences authorization and post-payment review. Claims are more defensible when the note clearly aligns to policy-recognized indications (e.g., abnormal bleeding evaluation or high-risk contexts).

7.2 Example: BCBS FEP policy environment

BCBS Federal Employee Program medical policy documents are frequently referenced in multi-payer environments as a “conservative” benchmark. Documentation should clearly indicate the clinical rationale when biopsy is performed and avoid presenting the service as screening.

7.3 Infertility policies and limitations

Some commercial policies restrict endometrial biopsy in infertility contexts unless there is suspicion of uterine pathology or other covered indications. This is a common denial driver when the note simply states “infertility evaluation” without abnormal bleeding or risk findings. Align the documentation to the actual reason the clinician performed the biopsy.

8. 2026 Medicare Physician Fee Schedule Context (Practical)

2026 Medicare Physician Fee Schedule (PFS) payment is governed by the CMS final rule and associated Federal Register publication. For coding teams, the key operational point is not memorizing a single national payment figure; it is ensuring the practice uses the current-year fee schedule for the correct locality, place of service, and participation status. CMS publishes the CY 2026 PFS final rule materials and summary guidance that establish the year’s payment policies and updates.

Practical steps for defensible payment estimation:

• Use CMS’s PFS data tools or your clearinghouse/charge master updated for CY 2026 to confirm the local allowable for 58100.
• Confirm whether the service is billed in a non-facility versus facility context and whether any site-of-service rules affect reimbursement.
• Ensure RVU/pricing assumptions used in patient estimates are updated to the CY 2026 rule set rather than prior-year values. Revenue-cycle caution: Even when a service is clinically appropriate, claims can deny if documentation implies a different procedure was performed (e.g., dilation) or if edits treat billed services as bundled under NCCI policy. Accurate code selection and documentation typically prevent more denials than payer appeal work.

9. Denial Risks, Audit Triggers, and Prevention Checklist

The most common denial patterns for 58100 are predictable and preventable. They cluster into coding mismatches, documentation insufficiency, and modifier-driven scrutiny.

9.1 High-frequency denial and audit patterns

• Coding mismatch: “dilation was performed” but 58100 was billed. Specialty coding guidance emphasizes documenting dilation necessity and selecting the appropriate alternative code pathway when dilation is required.
• Insufficient medical necessity narrative: AUB or postmenopausal bleeding not clearly described; risk factors not documented; procedure appears screening-like. AAFP guidance emphasizes documenting risk factors and clinical context.
• Improper same-day E/M billing: E/M billed without documentation supporting a separately identifiable service (modifier 25 misuse).
• Bundling/edit conflicts: Multiple gynecologic procedures billed together without documentation supporting separate reporting; NCCI policy provides the baseline compliance standard for integral services and “scout” procedures.
• Infertility workup limitations: Biopsy billed as part of infertility evaluation absent covered indications; certain payer policies restrict coverage in that context.

9.2 Prevention checklist (what to standardize)

• Indication statement: One sentence that clearly states the reason for biopsy (bleeding pattern/risk factors/findings).
• No-dilation clarity: Procedure note that makes it auditable that dilation was not performed (or, if dilation was required, document why and code accordingly).
• Specimen chain: “Specimen sent to pathology,” with results linkage and follow-up plan.
• Modifier governance: Require documentation elements before applying 25 or 59; avoid reflex modifier use.
• Payer-specific workflow: For infertility contexts or known restrictive plans, confirm coverage policy alignment before performing biopsy when feasible.

10. Real-World Coding Scenarios

Scenario 1: Office evaluation of abnormal uterine bleeding (AUB) in a higher-risk patient

Setting: Office (non-facility).

Service: Endometrial biopsy performed using Pipelle; no cervical dilation; specimen sent to pathology.

Documentation anchor: Note clearly describes bleeding pattern and risk profile consistent with risk-based guidance (age/risk factors).

Coding logic: Report 58100 for the sampling procedure and bill pathology separately per standard workflow.

Scenario 2: Postmenopausal bleeding with policy-driven documentation

Setting: Office/outpatient.

Service: Endometrial sampling without dilation due to postmenopausal bleeding evaluation.

Payer realism: Chart links the biopsy decision to abnormal bleeding evaluation consistent with payer medical policy frameworks for endometrial sampling.

Coding logic: 58100 is appropriate when the documentation supports sampling without dilation and an evaluative indication.

Scenario 3: Cervical stenosis requires dilation to obtain tissue

Setting: Procedural environment (may require analgesia/anesthesia).

Service: Attempted office biopsy unsuccessful; cervical stenosis documented; dilation required to obtain tissue.

Coding logic: Specialty coding guidance emphasizes that when dilation is performed to accomplish sampling, do not force 58100; document why dilation was needed and report the appropriate alternative procedure pathway.

Scenario 4: Same-day E/M for a separate clinical problem

Setting: Office visit plus biopsy.

Service: Patient evaluated for significant anemia management and medication planning in addition to biopsy decision; distinct assessment and plan documented.

Coding logic: E/M may be billed with -25 only when documentation supports that it is separately identifiable beyond routine pre-procedure work; AAFP guidance highlights this as a common pitfall area.

Scenario 5: Infertility evaluation without abnormal bleeding

Setting: Specialty clinic infertility workup.

Service: Proposed endometrial biopsy as a routine step without documented abnormal bleeding or uterine pathology suspicion.

Denial risk: Some payer infertility coverage policies restrict biopsy unless specific indications exist; document the covered indication or avoid performing as a routine screening-like service.