This page compares two distinct NUCC-taxonomy specialties tracked by the CMS National Plan and Provider Enumeration System: Certified Respiratory Therapist, which currently counts 1,585 enrolled providers across 48 U.S. states and territories, and Pulmonary Function Technologist Certified Respiratory Therapist, with 36 providers across 14 states. Each clinician on these rosters selected a primary NUCC code at NPI enrollment, so the totals measure how many providers self-identify their primary practice as Certified Respiratory Therapist or Pulmonary Function Technologist Certified Respiratory Therapist rather than the total population ever trained or credentialed in either field — dual-certified clinicians show up under whichever code they registered first.

On national volume, Certified Respiratory Therapist carries the larger provider roster (1,585 vs 36), and Certified Respiratory Therapist has the wider geographic footprint at 48 states versus 14. The top Certified Respiratory Therapist concentration sits in California (385 providers), while Pulmonary Function Technologist Certified Respiratory Therapist peaks in California (15). The per-capita columns in the table below normalize each state's raw count against 2023 Census population estimates, which matters because absolute provider counts track population scale first and specialty density second — a small state with a strong training pipeline can out-rank a larger state on per-100K availability.

Use this comparison to understand relative availability, not to judge clinical substitutability — Certified Respiratory Therapist and Pulmonary Function Technologist Certified Respiratory Therapist are distinct specialties with different scopes of practice, training requirements, and conditions they treat, even when their NUCC categories overlap. Important: PlainDoctor is a directory of publicly available CMS government data, not medical advice, a provider rating, or a recommendation about which specialty a patient should consult. Always work with a licensed clinician to determine which specialty is appropriate for your condition, verify any specific provider through the NPPES NPI Registry and the relevant state medical board, and consult the NUCC taxonomy documentation for the formal scope-of-practice definitions behind each specialty code.