The RPFT is a two-tier credential. Pass the NBRC's Pulmonary Function Technology (PFT) exam at the low cut score and you earn CPFT (Certified). Pass at the higher cut score and you earn RPFT (Registered). Both sit on the same 115-question, 2-hour exam, so your study list is identical; your prep just needs to reach a higher depth on the topics.
The exam has no prerequisites other than eligibility—you can hold an associate degree in respiratory care, be a current CRT/RRT, complete 62 semester hours of college credit with specific science coursework, or hold a current CPFT credential. NBRC does not require X years of field experience to take it, though technologists who have done the work tend to perform better because the questions assume hands-on familiarity with equipment and patient behavior.
The exam is calibrated around the technician who can operate, troubleshoot, and quality-control spirometers and body plethysmographs; perform spirometry and diffusion testing to standard protocol; collect blood samples; interpret blood gas results; and recognize when a test result is valid enough to report. It is not a test of respiratory physiology theory alone, though physiology underlies everything.
The 100 scored items break into three domains with unequal weight:
Domain | Item Count | Share |
|---|---|---|
Procedures | 44 | 44% |
Instrumentation / Equipment | 33 | 33% |
Data Management | 23 | 23% |
Procedures dominate because they are where most of the work happens. Equipment comes second—more than many candidates expect. Data Management, the smallest domain, tests your ability to calculate results, apply reference ranges, spot unreliable data, and interpret what a result means clinically.
The exam also specifies that approximately 10 of the 100 scored items involve pediatric patients; the remaining 90 cover general/adult populations.
Quality control faster than understanding it. The equipment domain includes setup, maintenance, calibration, troubleshooting, and—often overlooked—quality control procedures. Candidates often memorize what QC steps look like without grasping why. When the exam asks "What would you do if a body plethysmograph calibration syringe reads 5% low?" the answer depends on understanding what the syringe measures and what a 5% error means. Rote memory fails here. Study the logic, not just the checklist.
Blood gas analysis assumptions. Blood gas questions appear throughout all three domains. Many candidates studied acid-base in school years ago and assume they still know it. But the exam tests pattern recognition: you see a pH, PO₂, PCO₂, HCO₃ and need to name the disturbance and spot which value is compensatory. Pretest blood gas questions now; if you are rusty, rebuild from first principles, not just from a quick review.
Validity and reliability are not the same. A spirometry result can be technically valid (meets repeatability criteria) but clinically unreliable (the patient didn't try or the pattern looks wrong). The exam tests both. You need to know ATS/ERS acceptability criteria cold, but also recognize when something looks wrong on the curve even if it technically passes the numbers.
DLCO diffusion quirks. DLCO procedure questions get granular: hemoglobin correction, carboxyhemoglobin correction, alveolar volume calculation, the effect of low inspiration on DLCO validity. These are high-application-level questions, not simple recall. Weak DLCO knowledge costs points disproportionate to the procedure's percentage of the test.
Exercise testing—both field and monitored. The 6-Minute Walk Test and shuttle walk appear alongside electrocardiography-monitored exercise testing. Candidates sometimes study one or the other. The exam expects you to know when each is used, how to monitor safely, how to interpret stopping criteria, and how to handle cardiovascular events. It is rare but not impossible.
Methacholine and bronchial provocation. Airway responsiveness testing is included; candidates often skip it as "something specialists do." It appears on the exam and rewards knowing the protocol, the definitions of a positive response, and safety precautions.
Because the exam blends procedural steps with result interpretation with equipment logic, a good practice question has pedagogical value only if you understand not just the right answer but the pathway to it.
Build habits like these:
Track your performance by domain, not overall score. If you are missing more data management questions than 23% of your total misses, you have imbalance. Equipment at 40%+ of your misses signals that troubleshooting or QC logic is weak.
For any equipment or QC question you miss, draw the equipment. Sketch a spirometer, a plethysmograph, or a blood gas analyzer and label the parts relevant to the question. This forces conceptual understanding over pattern-matching.
Practice blood gas interpretation under time pressure. In the real exam, you won't have leisurely time to work through acid-base logic. After you've mastered the content, take mixed bags of blood gas questions with a timer.
Revisit ATS/ERS standards after every spirometry or DLCO question. NBRC calls out that ATS and ERS updates are critical for exam preparation. The free NBRC practice exam uses questions from past administrations; your practice bank should include questions updated to 2022+ standards.
Record yourself explaining why an answer is wrong. If you choose "the spirometry curve shows early termination so the test is invalid," but the correct answer is "the spirometry curve is valid, but the patient's effort was submaximal as evidenced by early termination," you need to hear yourself say the difference aloud to lock in the precision.
Not using the free NBRC practice exam first. NBRC publishes a free practice exam on its website. Many candidates skip it because they assume it is too easy or too different from the real test. It is neither. Taking it early tells you where your gaps are and calibrates your sense of pacing.
Cramming blood gas and spirometry interpretation into the last week. These two topics appear across multiple domains (procedures, data management, interpretation), and they are not amenable to last-minute cramming. They need distributed practice over weeks.
Ignoring pediatric-specific content until late prep. The exam explicitly includes approximately 10 pediatric items. Pediatric lung volumes are smaller, predicted values are age-dependent, and cooperation is harder to achieve. If your clinical experience is mostly adult, carve out study time for pediatric values, technique modifications, and expected findings.
Assuming that passing the CPFT means RPFT is close. The two cut scores exist because a material gap separates them. Candidates who pass CPFT on a first or second attempt sometimes sit for RPFT immediately and fail, thinking they are "almost there." Budget time as if you are starting from scratch; the higher cut score rewards depth, not just breadth.
Background | Timeline | Study Approach |
|---|---|---|
Current respiratory therapist with PFT rotation | 3–4 weeks | Spirometry validity, DLCO details, and blood gas patterns; light review of equipment QC. Focus on edge cases and ATS/ERS updates. |
Respiratory care graduate, limited PFT experience | 6–8 weeks | Balanced across all three domains; build equipment troubleshooting logic alongside procedure details and data interpretation. |
Non-respiratory background (62-credit route) | 10–12 weeks | Start with respiratory physiology and HVAC fundamentals before tackling PFT-specific content; slow-build on spirometry and blood gas. |
Retaking after CPFT fail | 4–6 weeks | Use score feedback to identify which domain cost you the most; audit your understanding of that domain's conceptual foundation. |
The current content outline became effective in October 2022. NBRC has not published a revised version since; outlines typically hold stable for several years before a refresh. Check the NBRC website for any announcements about a 2026 or 2027 update before you finalize your study plan, especially regarding ATS/ERS standards, which NBRC flagged as critical and may update independently of the full outline.Want to practice for another exam? Try our free National Certified Medical Assistant (NCMA) test.
Last updated on Oct, 7 2026
