- 2026 Blueprint Overview
- All 15 Domains and Their Weights
- The Two Heaviest Domains
- Core Clinical Domains (RBCs, Hazards, Surgery, Donors, OB/Peds)
- Specialized Product and Operations Domains
- The Small but Testable Domains
- How the Domains Show Up on Exam Day
- Registration, Fees, and Eligibility Mechanics
- Building a Domain-Weighted Study Plan
- Frequently Asked Questions
- The 2026 BB/TM blueprint has 15 domains; Clinical Practice (14%) and HPC Transplantation (11%) carry the most weight.
- The exam is 280 single-best-answer questions across six sections, blending written and practical material.
- Passing requires a criterion-referenced scaled score of 500, not a fixed raw percentage.
- The 2026 fee is $2,100, including a $200 nonrefundable administrative fee, with testing September 8-28, 2026.
2026 Blueprint Overview
The American Board of Pathology (ABPath) publishes a content specification for the Certification in Pathology: Blood Banking/Transfusion Medicine (BB/TM) examination, and the version dated January 2026 organizes everything a candidate needs to know into 15 ordered domains. These aren't arbitrary categories - they reflect how ABPath's content committee weights the actual practice of a transfusion medicine physician, from bedside consultation to component manufacturing to regulatory oversight.
Understanding the domain structure matters because the exam allocates its 280 questions according to these published percentages. A candidate who spends equal time on every topic is misallocating effort relative to how the exam is actually built. This guide breaks down each of the 15 domains, what they cover, and how to think about them relative to one another. For a broader strategy on turning this domain map into a study system, see the BB/TM Study Guide 2026.
All 15 Domains and Their Weights
The table below reproduces the official ordered domain list with the approximate Written/Practical percentages from the 2026 blueprint. The published weights total 100%.
| # | Domain | Weight |
|---|---|---|
| 1 | Clinical Practice | 14% |
| 2 | Histocompatibility and Tissue Banking | 1% |
| 3 | RBCs and RBC Components | 10% |
| 4 | Apheresis | 8% |
| 5 | Hazards of Transfusion: Specific Adverse Events | 10% |
| 6 | Plasma Components and Derivatives | 6% |
| 7 | Infectious Hazards of Transfusion | 4% |
| 8 | Blood Donors and Blood Collection | 7% |
| 9 | Management, Quality, Legal, & Regulatory Issues in Transfusion Med. & Transplantation | 6% |
| 10 | Surgery Patients | 7% |
| 11 | Biovigilance | 1% |
| 12 | Platelet and Platelet Components | 6% |
| 13 | Obstetric and Pediatric Patients | 7% |
| 14 | Hematopoietic Progenitor Cell (HPC) Transplantation | 11% |
| 15 | Management and Informatics-General | 2% |
If you're still confirming basic terminology before diving into content, start with What Is BB/TM? or BB/TM Meaning to make sure you're aligned on scope before mapping domains to study time.
The Two Heaviest Domains
Two domains dominate the blueprint, and both deserve early, repeated review rather than a single pass late in your prep.
Domain 1: Clinical Practice (14%)
The single largest domain covers the day-to-day consultative work of a transfusion medicine physician - indications for transfusion, dosing and component selection, massive transfusion protocols, and patient-specific decision-making that spans multiple other domains. Because it's the largest slice of the exam, it's also the domain most likely to appear woven into scenario-based questions that reference other topics.
- Transfusion thresholds and evidence-based indications across patient populations
- Massive transfusion protocol activation and component ratios
- Consultation scenarios requiring synthesis across multiple domains
Domain 14: Hematopoietic Progenitor Cell (HPC) Transplantation (11%)
The second-largest domain covers collection, processing, cryopreservation, and administration of HPC products, plus the clinical management issues unique to transplant patients. Candidates coming from a fellowship without heavy transplant service exposure often underestimate how much material this domain contains.
- HPC collection methods (marrow, apheresis, cord blood) and product processing
- Cryopreservation, thawing, and infusion-related complications
- Engraftment monitoring and transplant-specific adverse events
Key Takeaway
Together, Clinical Practice and HPC Transplantation make up more of the exam than the bottom six domains combined - plan your heaviest review blocks around these two first.
Core Clinical Domains (RBCs, Hazards, Surgery, Donors, OB/Peds)
A cluster of mid-to-high weight domains covers the clinical bread and butter of transfusion medicine practice. These domains frequently overlap in question stems, so studying them together in sequence is more efficient than isolating them.
Domain 3: RBCs and RBC Components (10%)
Covers red cell product types, storage lesion, irradiation, washing, and selection criteria for special populations. Expect questions that connect directly to Clinical Practice indications.
- Storage-related changes and shelf-life implications
- Special processing: irradiation, leukoreduction, washing
Domain 5: Hazards of Transfusion - Specific Adverse Events (10%)
Tied with RBCs as the third-largest domain, this covers hemolytic and non-hemolytic transfusion reactions, TRALI, TACO, and workup algorithms following an adverse event.
- Reaction classification and time-course differentiation
- Laboratory workup sequencing after a suspected reaction
Domain 10: Surgery Patients (7%)
Focuses on perioperative blood management, type and screen versus crossmatch decisions, and intraoperative cell salvage.
Domain 8: Blood Donors and Blood Collection (7%)
Covers donor eligibility criteria, deferral periods, and collection procedures - foundational material that also supports Apheresis and Biovigilance questions.
Domain 13: Obstetric and Pediatric Patients (7%)
Covers hemolytic disease of the fetus and newborn, neonatal exchange transfusion, and Rh immune globulin management - a self-contained but detail-heavy domain.
Specialized Product and Operations Domains
This group covers component-specific and operational domains in the mid-single-digit weight range. None is large enough to dominate your schedule alone, but collectively they represent a meaningful share of the 280 questions.
- Domain 4: Apheresis (8%) - therapeutic apheresis indications, procedure types, and complications, plus donor apheresis collection.
- Domain 6: Plasma Components and Derivatives (6%) - FFP, cryoprecipitate, and plasma-derived products including factor concentrates and immune globulins.
- Domain 9: Management, Quality, Legal, & Regulatory Issues in Transfusion Med. & Transplantation (6%) - FDA/AABB regulatory framework, quality systems, and legal considerations in transfusion practice.
- Domain 12: Platelet and Platelet Components (6%) - platelet collection methods, storage, refractoriness, and transfusion thresholds.
The Small but Testable Domains
Four domains sit at 4% or below. They're easy to deprioritize, but a candidate who skips them entirely leaves points on the table that a modest review session could capture.
Domain 7: Infectious Hazards of Transfusion (4%)
Transfusion-transmitted infections, donor testing algorithms, and emerging pathogen screening.
Domain 15: Management and Informatics-General (2%)
Blood bank information systems, barcode verification, and computer crossmatch logic.
Domain 2: Histocompatibility and Tissue Banking (1%)
HLA typing basics as they relate to platelet refractoriness and transplant compatibility, plus tissue banking fundamentals.
Domain 11: Biovigilance (1%)
Hemovigilance reporting systems and adverse event surveillance at the institutional and national level.
Domains 2 and 11 each carry only 1% of the exam, but that still translates to a small, predictable number of questions. A focused review session - not a deep dive - is the appropriate level of effort here.
How the Domains Show Up on Exam Day
The BB/TM exam is a one-day, computer-based test with 280 single-best-answer multiple-choice questions delivered across six sections at Pearson VUE Professional Testing Centers. Domains aren't tested as separate labeled blocks - instead, written and practical material combining images, charts, graphs, tables, diagrams, formulas, and antibody-identification panels are distributed throughout the six sections according to the blueprint weights.
The 2026 schedule allows six hours and 22 minutes of actual testing time, with the full scheduled day running eight hours 52 minutes once you account for the tutorial, survey, lunch, and other breaks. That means pacing across all 15 domains - not just the heavily weighted ones - matters for finishing on time. For a detailed breakdown of what a passing performance actually requires, see BB/TM Passing Score 2026: Exactly What You Need to Pass, and for a candid assessment of overall difficulty across these domains, read How Hard Is the BB/TM Exam?
Key Takeaway
Practical material - antibody panels, calculations, and image-based questions - is woven throughout multiple domains rather than confined to one section, so don't assume "practical" skills only matter for RBCs or Apheresis.
Registration, Fees, and Eligibility Mechanics
Before domain content even matters, candidates need to clear ABPath's eligibility gate. This requires AP/CP or CP primary certification (or primary certification from another ABMS member board), plus 12 months of ACGME-accredited Blood Banking/Transfusion Medicine fellowship training. A qualifying medical degree, program verification, and a full unrestricted medical license round out the requirements. Full details are covered in BB/TM Requirements 2026.
The 2026 examination fee is $2,100, which includes a $200 nonrefundable administrative fee - a cost breakdown worth reviewing in full at BB/TM Certification Cost 2026. Testing occurs during a defined window of September 8-28, 2026; scheduling logistics and deadlines are covered in BB/TM Exam Dates 2026.
Passing uses a criterion-referenced scaled score of 500 rather than a fixed raw percentage cutoff, meaning the difficulty of a given year's question mix is statistically adjusted. According to ABPath's 2025 Annual Report, the overall pass rate that year was 90% (44/49), with a 91% first-time rate (39/43) and an 83% repeat-taker rate (5/6). For the full context behind these numbers, see BB/TM Pass Rate 2026: What the Data Shows.
Building a Domain-Weighted Study Plan
Once you know the weights, the most efficient scheduling approach allocates review time roughly proportional to domain percentage, with earlier and repeated exposure to the heaviest domains rather than a single late pass.
Clinical Practice + RBCs
- Build the foundation since Clinical Practice questions reference other domains constantly
- Pair with RBC/component selection criteria
HPC Transplantation + Hazards of Transfusion
- Work through HPC processing and adverse reaction algorithms together
- Drill antibody-identification panels alongside reaction workups
Apheresis, Surgery, Donors, OB/Peds
- Cover the 7-8% domains as a cluster
- Practice calculation-heavy questions in this block
Plasma, Platelets, Management/Quality
- Consolidate the 6% domains together
- Review regulatory and quality-system frameworks
Small domains + full review
- Give Histocompatibility, Biovigilance, Infectious Hazards, and Informatics a focused single pass
- Run timed practice covering all 15 domains proportionally
Practicing with domain-weighted question sets on our BB/TM practice test platform is a practical way to confirm your timing holds up across all six sections, not just your strongest domains. For a condensed reference to keep nearby during final review, bookmark the BB/TM Cheat Sheet 2026.
Key Takeaway
Don't save the 1-2% domains for the final days before your exam - a short, dedicated review earlier in your schedule prevents last-minute cramming of unfamiliar material like Biovigilance and Histocompatibility.
Frequently Asked Questions
There are 15 domains, defined in ABPath's content specification dated January 2026, with published Written/Practical weights that total 100%.
Clinical Practice, at 14%, is the largest domain and frequently intersects with other topics in scenario-based questions, making it a logical starting point.
Yes. Each carries roughly 1% of the exam, which still corresponds to a predictable handful of questions worth capturing with focused, time-limited review.
No. The 280 questions are distributed across six combined written and practical sections according to blueprint weights, not organized into 15 distinct labeled blocks.
This guide covers Certification in Pathology: Blood Banking/Transfusion Medicine (BB/TM) issued by the American Board of Pathology, a physician subspecialty credential distinct from the SBB(ASCP) laboratory specialist certification. See What Does BB/TM Stand For? and BB/TM Certification for clarification on scope.
Whether you're mapping out fellowship-year study time or finalizing review in the weeks before your Pearson VUE appointment, treating the 15 domains as a weighted checklist - not a flat list - is the most direct way to align your preparation with how the exam is actually built. Explore more BB/TM-specific breakdowns, including Is the BB/TM Certification Worth It? and BB/TM Jobs, as you plan your path through certification and beyond.