Recurrent Pregnancy Loss Workup Billing: CPT and ICD-10 Guide

Recurrent pregnancy loss (RPL) — defined by ASRM as two or more confirmed clinical pregnancy losses — triggers a diagnostic workup that spans laboratory testing, genetic evaluation, uterine imaging, and immunological studies. From a billing perspective, the RPL workup generates more distinct claim lines than almost any other fertility-adjacent service, with test panels drawn from hematology, genetics, endocrinology, and radiology, each carrying its own CPT code and coverage rules. Understanding how to code, bill, and document RPL services correctly is essential to collecting on this revenue — and to avoiding the denials that follow when claims lack specificity or documentation does not support the tests ordered.

Unlike a discrete IVF cycle, an RPL workup is an extended diagnostic process that may span multiple encounters and involve multiple ordering providers and reference labs. Claims can legitimately include the treating REI, a genetic counselor, a hematologist, and a pathology lab — all billing under the same episode of care. Coordinating coding across that service landscape requires a clear understanding of which codes belong on which claim, under whose NPI, and how each payer segments diagnostic coverage from the infertility benefit. Practices that treat the RPL workup as a loosely organized series of orders rather than a structured billing workflow consistently underperform on this service line.

What Constitutes an RPL Diagnostic Workup

ASRM's clinical guidelines recommend the following components in a thorough RPL evaluation. Not every patient receives every test — workup design should reflect documented clinical indication — but the billing team must be prepared to code accurately for all of them.

• Antiphospholipid antibody panel: cardiolipin IgG, IgM, and IgA; beta-2 glycoprotein I antibodies; and a lupus anticoagulant screen with confirmatory testing
• Thrombophilia panel: Factor V Leiden gene analysis, Prothrombin G20210A gene analysis, Protein C activity, Protein S activity, and Antithrombin III
• Parental karyotype analysis for both partners using peripheral blood chromosome analysis with banding
• Uterine cavity evaluation via saline infusion sonohysterography (SIS), hysterosalpingography (HSG), or diagnostic hysteroscopy depending on clinical suspicion
• Thyroid function testing: TSH and anti-thyroid peroxidase (TPO) antibodies, as subclinical thyroid dysfunction is associated with early loss
• Ovarian reserve assessment: cycle day 3 FSH and estradiol, AMH level, and antral follicle count if indicated
• Prolactin level — elevated prolactin is associated with luteal phase insufficiency and early pregnancy loss
• Evaluation for Müllerian anomalies and intrauterine pathology such as submucous fibroids, polyps, and intrauterine adhesions

ICD-10 Coding for RPL

The primary diagnosis code for RPL in a non-pregnant patient is N96 (Habitual aborter). This code should be the first-listed diagnosis on all claims for diagnostic services ordered as part of the RPL evaluation — lab draws, imaging studies, and office visits alike. When the patient is currently pregnant and has an established RPL history, codes from the O26.2x series apply. Secondary diagnosis codes should be added to subsequent claims once an underlying etiology is established by testing.

CPT Codes for the RPL Workup by Category

The following table covers the major CPT codes used across the standard RPL workup. Code selection must match the specific test methodology documented in the laboratory or procedure report. Submitting a panel code when individual tests were ordered and reported separately — or billing only one unit of a per-class code when multiple immunoglobulin classes were tested — are two of the most common collection failures in RPL billing.

Antiphospholipid Syndrome Testing: Code Selection in Detail

Antiphospholipid syndrome (APS) is the only immune-mediated cause of RPL with robust evidence and established treatment (low-dose aspirin plus low-molecular-weight heparin during pregnancy). APS testing is considered standard of care for all patients with two or more confirmed losses. The panel spans both serology and coagulation testing — two categories that typically arrive on separate claim lines from the same reference lab and require distinct billing knowledge.

Cardiolipin antibody (86147) is billed as one unit per immunoglobulin class tested. A standard panel testing IgG and IgM requires two units of 86147; if IgA is also run, submit three units. Beta-2 glycoprotein I (B2GP1) antibody — the third Sapporo diagnostic criteria component — does not have its own standalone CPT code and is typically billed under 86849 (unlisted immunology procedure) by most reference labs. Verify with your lab how they code B2GP1 before submitting the claim; some use proprietary HCPCS codes on the UB-04 and bill only the technical component, which means the practice must bill the interpretation separately on the professional claim. Leaving B2GP1 off the claim is both a revenue loss and a documentation gap if the chart shows all three Sapporo tests were ordered.

Lupus anticoagulant (LA) testing follows a multi-step algorithm that generates several separately billable CPT codes. The dRVVT screen (85705) is the first step. A positive screen triggers confirmatory testing (85597 and 85598), and a mixing study using the aPTT (85730) is also performed to distinguish inhibitor from factor deficiency. These codes appear on the laboratory's claim, not the physician's claim. If the practice draws the blood and ships it to a reference lab, ensure patients are counseled that the reference lab will bill their insurance separately under the lab benefit rather than the medical benefit — a distinction that affects cost-sharing calculations.

Parental Karyotyping: Two Patients, Two Claims

Parental karyotype analysis requires peripheral blood draws from both partners. Two patient accounts are involved, and the laboratory must generate two separate claims — one per patient. For the female partner, N96 is the primary diagnosis. For the male partner, the appropriate code is N46.9 (Male infertility, unspecified) or a more specific male factor code if documented, because the male partner does not carry the N96 diagnosis. Filing both karyotypes under the female patient's account is a compliance violation — the male partner's services are submitted under a different patient name and policy — and the male partner's insurer will reject the claim.

Each karyotype requires two CPT codes: 88230 (tissue culture setup for lymphocyte culture from peripheral blood) and 88262 (chromosome analysis with banding and karyotype interpretation). Both codes apply to each partner separately. If the couple uses the same reference lab under a single specimen requisition, confirm that the lab creates two distinct orders and submits two separate claims. Some labs bundle both specimens into a single order for operational convenience — this must be corrected before billing, not after, because a commingled claim cannot be split retroactively without a corrected claim submission and potential refund if the insurer already paid.

Uterine Evaluation: Choosing and Coding the Correct Modality

Saline infusion sonohysterography (SIS) is typically the first-line uterine evaluation for RPL given its low cost, high sensitivity for intracavitary pathology, and absence of radiation exposure. SIS is billed with CPT 76831 (the imaging component) and CPT 58340 (catheterization and saline instillation). Verify whether your commercial payer bundles 58340 into 76831 before submitting both codes — some plans treat 58340 as an incidental service and pay only 76831. When both codes are separately payable, 58340 adds meaningful reimbursement to the encounter and should always be captured.

When HSG is the chosen modality, bill 74740 for the radiologic procedure. If the physician performs and supervises the fluoroscopic imaging in a practice-owned setting, bill the global code (no modifier). If performed in a hospital outpatient radiology department where the facility bills the technical component under the UB-04, the physician submits 74740 with modifier 26 for the professional component only. Submitting the global code in a facility setting creates a billing conflict and exposes the practice to overpayment recoupment demands.

Diagnostic hysteroscopy (58555) is the most accurate modality for intrauterine pathology but the most resource-intensive and the most likely to require prior authorization. When hysteroscopy reveals pathology that is treated during the same operative session — a polyp removed (58558), intrauterine adhesions lysed (58559), uterine septum resected (58560), or submucous fibroid removed (58561) — report the appropriate operative hysteroscopy code, not 58555. The diagnostic component is bundled into operative hysteroscopy codes when the operative procedure was the planned and performed objective. Reporting 58555 alongside an operative code for the same session will trigger a NCCI bundling edit and generate a denial.

Insurance Coverage: Diagnostic Benefit vs. Infertility Benefit

RPL workup services occupy a favorable billing position: they are diagnostic rather than therapeutic, which typically places them under the patient's standard diagnostic benefit rather than the infertility or ART benefit. This distinction matters because the diagnostic benefit often has no cycle limits, no lifetime dollar maximums, and no state mandate restrictions — restrictions that apply to the fertility treatment benefit. Services documented and coded as investigation of the etiology of pregnancy loss collect at a higher rate and generate fewer authorization battles than the same clinical activities coded under an infertility treatment framework.

Some commercial payers include a blanket coverage exclusion written as "diagnosis and treatment of infertility" that is broad enough to capture RPL workup services if the claim contains a general infertility code like N97.9. When a denial cites this exclusion against N96-coded claims, the correct response is a written appeal arguing that RPL (N96, habitual aborter) is a clinically and diagnostically distinct condition from infertility (N97.x, failure to achieve pregnancy), that ASRM, ACOG, and the ICD-10-CM classification system treat them as separate diagnoses, and that the services at issue were ordered to investigate the cause of established pregnancy loss — not to treat the failure to conceive. Payers frequently reverse these denials on first-level appeal when the distinction is made clearly in writing with supporting clinical documentation.

Common RPL Billing Errors

• Using N97.9 (female infertility, unspecified) as the primary diagnosis instead of N96 — routes the claim to the infertility benefit, where it may be subject to cycle limits, dollar caps, or an outright plan exclusion that would not apply under the diagnostic benefit with N96.
• Submitting CPT 86147 as one unit when three immunoglobulin classes were tested — each of IgG, IgM, and IgA is a separately billable unit of service. Filing one unit when three were run understates the service and leaves reimbursement uncollected.
• Filing the male partner's karyotype (88230, 88262) under the female patient's account — a compliance violation and a guaranteed denial from the male partner's insurer because the name, date of birth, and policy number will not match.
• Omitting CPT 58340 when billing SIS (76831) — catheterization is a separately reimbursable service at most payers and should always be captured on dates when SIS is performed.
• Billing the global code for HSG (74740) in a hospital outpatient setting where the physician provided only the professional component — requires modifier 26 when the facility owns the equipment and bills the technical component separately.
• Submitting all RPL workup labs under a single claim date when draws occurred on multiple separate service dates — date-of-service inaccuracies cause claim rejections that require corrected claim resubmissions and delay payment by weeks.
• Reporting diagnostic hysteroscopy (58555) alongside an operative hysteroscopy code (58558, 58559, 58560, or 58561) for the same session — NCCI bundles the diagnostic component into operative hysteroscopy, and the duplicate code triggers an automatic denial.

Documentation Requirements That Support RPL Claims

RPL workup claims attract heightened payer scrutiny because they involve high-cost genetic tests, specialized coagulation studies, and frequently both partners. Every element of the workup must be supported in the medical record before a claim is submitted. The following documentation elements are most frequently cited in denial justifications and audit findings.

• Confirmed pregnancy loss count and type: the medical record must document at least two confirmed clinical pregnancy losses, defined as losses visualized by ultrasound or confirmed by histopathology. A positive home pregnancy test followed by a negative serum beta-hCG, without ultrasound confirmation or pathology, does not meet the clinical RPL definition for most payer coverage criteria and will result in denial when the claim is reviewed.
• Specific clinical indication for each test ordered: the chart note or order must document why each test panel was ordered for this patient. "RPL workup" alone is insufficient justification for genetic tests or specialized coagulation studies. Document the specific rationale: prior DVT, family history of chromosomal translocation, clinical suspicion based on loss pattern, or documented abnormal screening result.
• Secondary diagnoses added after confirmed results: when APS is confirmed (D68.61) or a chromosomal translocation is identified (Q95.0), add the secondary code to the chart and to all subsequent treatment claims. Heparin or aspirin therapy billed without the confirmed APS secondary diagnosis will deny for insufficient diagnosis.
• Provider NPI matching the performing or ordering provider: each service must be billed under the individual NPI of the ordering or performing provider when the payer requires it. Using only the group NPI for specialty laboratory or genetic testing causes claim rejections at payers that mandate individual NPIs for these service categories.
• Genetic counseling documentation: if a genetic counselor provides pre- or post-test counseling (billed as CPT 96040), the counseling note must document the session content, the specific genetic risks discussed, and the patient's acknowledgment of test implications. Without documentation specifically describing the counseling service, 96040 will be denied as not separately identifiable from the associated office visit.

Office Visit E&M Coding for RPL Consultations

The initial RPL evaluation is typically a new patient visit billed at 99203, 99204, or 99205 depending on the complexity of medical decision-making. Given the volume of decisions involved — reviewing prior loss history and prior records, ordering a multi-panel workup across several testing categories, counseling the couple on potential etiologies and statistical recurrence risk, and coordinating ancillary testing — these consultations frequently support the highest new patient E&M level (99205) under the 2021 AMA MDM framework. To support 99205, the documentation must reflect multiple diagnoses being considered, data being ordered and reviewed from multiple independent sources, and risk of harm to the patient if underlying causes are not identified.

Follow-up visits to review workup results (99212–99215) support 99214 or 99215 when the note documents the number and complexity of problems being managed, specifically which data were reviewed and analyzed, and what management decisions were made in response to the findings. A visit note that records only "reviewed labs — plan discussed" does not support 99215 and will be downcoded on audit. Document which specific test results were reviewed, what the abnormal findings were, how they inform the working diagnosis and differential, and what treatment or monitoring plan was established as a direct result of the data review.

RPL workup billing ultimately rewards practices that build structured workflows around the service. Capture each service at the point of care, verify coverage for the thrombophilia and genetic panels before ordering, confirm parental karyotype billing is split correctly across two patient accounts, and document clearly enough that the claim can survive an appeal if it is denied. The CPT codes are well-established, the clinical indication is unambiguous, and the revenue is real — the collection failures come from workflow gaps and documentation shortcuts, not from inherent billing complexity.