CPT® Code 86901

Quick Reference

• Code definition: CPT 86901 reports serologic Rh(D) antigen testing of a blood specimen to determine Rh-positive or Rh-negative status; the laboratory mixes patient red blood cells with anti-D reagent antibody and observes for agglutination.
• Key billing rule: 86901 is a statutory exclusion from the Medicare Physician Fee Schedule (MPFS Status Code X); it is paid exclusively under the Clinical Laboratory Fee Schedule (CLFS) by the performing laboratory. Standard MPFS modifier rules (26, TC, 51, 50) do not apply.
• Modifier essentials: Modifier 90 (reference lab) applies when testing is performed by an outside laboratory; modifier 91 applies for a repeat test on the same date of service for a new, clinically necessary specimen, but the MUE of 1 (MAI 3) means the claim will go to medical review rather than auto-approve.
• Documentation must-have: A physician or provider order establishing the clinical indication (pre-transfusion workup, prenatal care, transplant evaluation) must be present; the result (Rh-positive or Rh-negative) must be recorded in the medical record.
• Top confusion point: When all components of an obstetric panel (80055 or 80081) are performed, bill the panel code, not 86900 and 86901 individually. Unbundling panel components is a documented OIG compliance risk [1].
• Payer alert: In the hospital outpatient setting (OPPS), 86901 carries APC Status Indicator STV-Packaged; payment is bundled into the APC for the associated procedure and the code is not separately reimbursed.
• CLIA requirement: 86901 is not CLIA-waived. The performing laboratory must hold moderate or high complexity CLIA certification depending on the methodology used [3].
• MUE: 1 unit per date of service; MAI 3 (Date of Service, Clinical), the most restrictive tier, not overridable with modifiers [2].

When to Use This Code

86901 captures the serologic determination of the Rh(D) antigen status of a blood specimen. Three primary clinical indications drive utilization: pre-transfusion compatibility workup, obstetric and prenatal care, and solid organ or hematopoietic stem cell transplant evaluation.

Pre-transfusion: Anti-D antibodies can cause severe hemolytic transfusion reactions, making Rh(D) status essential before any red blood cell transfusion. 86901 is performed as part of every type-and-screen or type-and-crossmatch workflow.

Prenatal care: Universal obstetric standards require Rh(D) typing at the first prenatal visit. For Rh-negative patients, repeat typing at approximately 28 weeks guides Rh immune globulin (RhIg/RhoGAM) prophylaxis decisions. 86901 is also indicated following sensitizing events in Rh-negative pregnant patients, including amniocentesis, spontaneous or induced abortion, antepartum hemorrhage or trauma, and delivery of an Rh-positive infant.

Transplant evaluation: Rh compatibility is assessed as part of donor and recipient workup for solid organ and hematopoietic stem cell transplant.

86901 is reported by the laboratory performing the test, billed under the CLFS. It is not a physician professional service code. The performing laboratory, whether independent, hospital outpatient, or physician office, must hold appropriate CLIA certification.

Code Differentiation Table

The critical differentiator for 86901 versus 86906: use 86906 whenever the full Rh antigen profile is clinically indicated (chronic transfusion patients, alloimmunized patients). Billing 86901 alongside 86906 misrepresents the service performed.

flowchart TD
    A[Rh blood typing ordered] --> B{Full obstetric panel\nall components performed?}
    B -->|Yes| C[Bill 80055 or 80081\nNOT 86900 + 86901]
    B -->|No| D{Full Rh phenotype\nC, c, D, E, e needed?}
    D -->|Yes| E[Bill 86906\nNOT 86901]
    D -->|No| F[Bill 86901\nAdd 86900 if ABO also performed\nAdd 86850 if antibody screen performed]

Billing & Modifier Rules

Fee schedule: 86901 is a statutory exclusion from the MPFS (Status Code X). Payment is made exclusively under the CLFS by the laboratory performing the test. Physicians cannot bill this code to the MPFS and expect reimbursement. Standard MPFS modifier rules are inapplicable because the PCTC Indicator is 9 (Not Applicable).

Modifier 90 (reference lab): The most commonly used modifier with 86901, appearing on 76% of claims in available data. Apply when the test is sent to an outside reference laboratory. The referring lab bills with modifier 90; the reference laboratory may bill directly depending on individual payer rules.

Modifier 91 (repeat lab test): Apply when the same test is performed on the same date of service for a new, clinically necessary specimen, not to confirm initial results or due to equipment failure. Because the MUE is 1 (MAI 3), claims with modifier 91 go to medical review rather than auto-adjudicating. Documentation must clearly establish the clinical reason a repeat test was medically necessary on the same date [2].

MUE = 1, MAI 3: One unit per date of service. The MAI 3 designation means modifier 59 and the X-modifiers (XE, XS, XU) do not override this limit. Claims for more than one unit will auto-deny at the MUE edit level [2].

Panel bundling: When all required components of the obstetric panel are performed, bill 80055 or 80081 rather than individual component codes. Billing 86900 and 86901 separately when a panel was fully performed is unbundling and a documented OIG compliance concern [1].

Crossmatch workflow: Compatibility testing codes 86920 through 86923 incorporate blood typing as a prerequisite laboratory step. Billing 86901 on the same date of service as crossmatch codes without distinct clinical justification for separate typing may constitute unbundling. Verify current NCCI PTP tables for specific edit pairs before billing both on the same date [2].

Outpatient hospital (OPPS): APC Status Indicator STV-Packaged means 86901 is not separately reimbursed in the hospital outpatient setting. Payment is packaged into the APC for the associated procedure. Facilities should account for this when projecting expected reimbursement for blood bank services.

Documentation Essentials

Required elements:

• Physician or provider order identifying the clinical indication
• Patient diagnosis supporting medical necessity
• Specimen collection documentation (collection date, time, specimen type)
• Test result: Rh-positive or Rh-negative

For prenatal context specifically:

• Gestational age at time of testing
• First trimester visit documentation for initial typing, or 28-week visit documentation for the repeat test in Rh-negative patients
• For post-sensitizing event RhIg candidacy: type and date of the sensitizing event, confirmed Rh-negative status, and clinical decision regarding RhIg administration

Audit red flags:

• Claims for 86901 without a supporting diagnosis establishing clinical need; reflexive billing on all specimens without documented indication is a compliance risk per OIG guidance [1]
• Claims for 86901 alongside 86920 through 86923 on the same date of service without documentation of a separate clinical reason for independent blood typing
• Component codes billed individually when the full obstetric panel was performed
• Claims with units greater than 1 per date of service

Medical necessity: Documentation must tie 86901 to a specific clinical event (pre-surgical transfusion preparation, prenatal screening visit, sensitizing event, transplant evaluation). Absence of a clinical indication in the medical record is the primary driver of medical necessity denials.

Medicare, Commercial & Medicaid Payer Rules

Medicare:

86901 is paid under the CLFS. Independent laboratories, hospital outpatient labs, and physician office labs bill under the CLFS. Annual CLFS rates are updated through the PAMA (Protecting Access to Medicare Act) private payor rate reporting methodology; verify the current 2026 payment amount directly from CMS CLFS files [4].

Medicare coverage for pre-transfusion blood typing is supported by NCD 110.10 (Blood Transfusions), which governs transfusion services broadly [5]. There is no standalone NCD or LCD specifically for 86901; coverage is medical necessity-driven on a per-encounter basis. CMS imposes no national frequency limitation, but repeated claims without a new clinical event (new pregnancy encounter, new transfusion episode) may trigger medical review.

In the hospital outpatient setting, 86901 carries APC Status Indicator STV-Packaged and is not separately reimbursable under OPPS.

Commercial payers:

Commercial coverage of Rh(D) typing is broadly consistent with clinical standards. Panel bundling rules (80055 and 80081) apply with commercial payers as well. Verify individual payer policies for any frequency limitations or prior authorization requirements, particularly for repeat Rh typing in chronic transfusion programs or alloimmunized patients.

Medicaid:

Most state Medicaid programs cover Rh(D) typing as medically necessary for prenatal care and transfusion services. Verify state-specific fee schedules and managed Medicaid plan authorization requirements, as these vary considerably.

Common Denials & Prevention

Denial: Zero payment due to MPFS routing 86901 carries MPFS Status Code X (Statutory Exclusion). Claims routed to the MPFS by physicians or practices will receive $0 reimbursement. Prevention: Ensure billing system configuration routes 86901 exclusively to the CLFS. Verify the claim form and fee schedule assignment before submission.

Denial: Units exceed MUE The MUE of 1 (MAI 3) means claims for more than one unit auto-deny [2]. Prevention: Enforce a unit cap of 1 for 86901 in the billing system. For a medically necessary repeat test on the same date of service, append modifier 91 with explicit documentation of the clinical reason; expect medical review.

Denial: Unbundling from obstetric panel When 86900 and 86901 are submitted individually on a date when all obstetric panel components were performed, payers may deny or recoup the individual codes as improperly unbundled [1]. Prevention: Implement a billing rule to verify panel completeness before coding component tests individually. When all components of 80055 or 80081 are ordered and resulted on the same date of service, bill the panel code.

Denial: Bundled with crossmatch codes Billing 86901 on the same date of service as 86920 through 86923 may trigger NCCI review when blood typing is inherent to the crossmatch workflow [2]. Prevention: Verify current NCCI PTP edits between 86901 and crossmatch codes. If separate typing was performed for a distinct clinical reason (for example, emergency re-typing to investigate a suspected compatibility error), document this clearly and apply modifier 59 with supporting documentation.

Denial: Missing medical necessity documentation Claims without a supporting diagnosis or provider order establishing clinical indication are denied on medical necessity grounds. Prevention: Every 86901 claim must be supported by a diagnosis code tied to a documented clinical event. For prenatal claims, Z34.xx codes support medical necessity; for pre-surgical claims, Z01.812 or the surgical diagnosis applies; for transfusion workup, the underlying condition driving the transfusion need applies.

Coding Scenarios

Scenario 1 — First Prenatal Visit, Complete Obstetric Panel

A 24-year-old patient presents for her initial prenatal visit at 9 weeks gestation. The laboratory performs all components of the obstetric panel: CBC, hepatitis B surface antigen, rubella antibody, syphilis screen, RBC antibody screen, ABO typing, and Rh(D) typing.

Correct coding: 80055 with diagnosis Z34.01

Why: All required components of the obstetric panel were performed. The panel code governs; billing 86900 and 86901 individually here is unbundling.

Scenario 2 — Pre-Operative Type and Screen, Non-Obstetric Patient

A 58-year-old patient scheduled for elective total knee arthroplasty undergoes a pre-operative blood bank type and screen. The laboratory performs ABO typing, Rh(D) typing, and an RBC antibody screen.

Correct coding: 86900 + 86901 + 86850 with diagnosis Z01.812; billed under CLFS

Why: No obstetric panel applies in a non-prenatal context. All three codes are separately reportable. If a crossmatch (86920) is subsequently performed, review NCCI PTP edits before billing blood typing on the same date [2].

Scenario 3 — Rh-Negative Patient at 28 Weeks, Repeat Rh Typing for RhIg

A documented Rh-negative patient presents for her 28-week prenatal visit. The provider orders a repeat Rh(D) typing and RBC antibody screen prior to administering RhIg. The obstetric panel was fully billed at the first prenatal visit.

Correct coding: 86901 + 86850; if RhIg is administered, also report 90385; diagnosis Z34.32 with Z31.82 as secondary

Why: Only the individually ordered tests are coded at this encounter; the full panel is not being performed. 86901 is separately reportable in this context, as it falls outside the obstetric panel framework for this visit.

Scenario 4 — Sickle Cell Patient Requiring Extended Rh Phenotyping

A patient with sickle cell disease on a chronic transfusion program requires extended Rh antigen phenotyping. The blood bank performs full Rh phenotyping (C, c, D, E, e) along with Kell antigen testing.

Correct coding: 86906 + 86905 (per additional antigen system); diagnosis D57.1

Why: 86906 captures the complete Rh antigen profile, including Rh(D). Billing 86901 alongside 86906 is unbundling. 86905 is separately reportable for each non-ABO, non-Rh antigen system tested (Kell, Duffy, Kidd).

Related Codes

• 86900 — Blood typing, serologic; ABO: virtually always ordered and billed alongside 86901 for a complete blood type; separately reportable
• 86850 — Antibody screen, RBC, each serum technique: third component of a full type-and-screen; separately reportable alongside 86901
• 86906 — Blood typing, serologic; Rh phenotyping, complete: use instead of 86901 when the full C, c, D, E, e profile is clinically required; encompasses Rh(D)
• 86905 — Blood typing, serologic; RBC antigens other than ABO or Rh (D), each: Kell, Duffy, Kidd, and other antigen systems; reported per antigen system
• 86920 — Compatibility test each unit; immediate spin technique: crossmatch; blood typing is a prerequisite step; review NCCI edits for same-date billing with 86901
• 80055 — Obstetric panel: replaces 86900 and 86901 when all panel components are performed at a prenatal visit
• 80081 — Obstetric panel (includes HIV testing): replaces 86900 and 86901 when all panel components including HIV are performed
• 90385 — Rho(D) immune globulin, mini-dose, IM: commonly follows 86901 in the prenatal context when Rh-negative status is confirmed and RhIg is administered

Sources

1. HHS OIG Compliance Program Guidance for Clinical Laboratories — HHS OIG — Unbundling, billing compliance, and fraud risk areas for clinical laboratories, including panel component billing
2. CMS NCCI Edits — MUE Tables and PTP Edits — CMS, effective 04-01-2026 — MUE of 1 (MAI 3) for 86901 and 86900; procedure-to-procedure bundling edits
3. CDC CLIA Program — CDC — CLIA certificate requirements; confirms 86901 is not CLIA-waived
4. CMS Clinical Laboratory Fee Schedule — CMS — CLFS payment rates for laboratory codes including 86901; updated annually under PAMA
5. CMS Medicare Coverage Database — NCD 110.10 Blood Transfusions — CMS — National coverage determination governing transfusion services; supports coverage of pre-transfusion blood typing