Dr. William L. Johnson, MD
Pediatrics (Pediatric Allergy/Immunology Physician)
At a glance
- In the NPI registry since
- 2005
The NPI date is when this clinician registered for a National Provider Identifier, the billing number used on health claims. It is not a license, graduation or board-certification date. NPIs were first issued in May 2005 and became required on claims in 2007–2008, so an early date usually means the clinician was already in practice before then. What an NPI is
Education and training
- 2005Registered with an NPI (national billing number; not a license date) — NPIs began in 2005, so practice likely started earlier
Medicare’s Care Compare data doesn’t list this clinician’s medical school. Undergraduate school, residency, fellowship, licensing exams and board certification aren’t in public federal data. Board certification can be confirmed with the certifying board (ABMS member boards for MDs, AOA boards for DOs).
Specialties and state licenses
-
Pediatric Allergy/Immunology Physician primary
MO license R1F19 -
Pediatrics Physician
MO license R1F19
As reported to the NPI registry. To confirm a license is current, check the state medical board.
Medicare patients and services
| Service | Times | Patients |
|---|---|---|
| Test for allergy using allergenic extract | 836 | 15 |
| Professional service for preparation and provision of 1 or more antigens | 400 | 31 |
| Professional service for multiple injections of allergen | 243 | 31 |
| Established patient office or other outpatient visit, 30-39 minutes | 96 | 67 |
| Administration and interpretation of patient-focused health risk assessment | 88 | 58 |
| Test to measure rate of airflow | 84 | 55 |
| Established patient office or other outpatient visit, 20-29 minutes | 31 | 29 |
| New patient office or other outpatient visit, 45-59 minutes | 13 | 13 |
| New patient office or other outpatient visit, 30-44 minutes | 13 | 13 |
Medicare fee-for-service only. CMS leaves out services billed for fewer than 11 patients. These figures describe a practice’s Medicare work; they aren’t a measure of quality.
Medicare prescriptions
| Drug | Prescriptions |
|---|---|
| Trelegy Ellipta (fluticasone/umeclidin/vilanter) Other prescribers in Saint Louis, MO | 41 |
| Montelukast Sodium Other prescribers in Saint Louis, MO | 37 |
| Fluticasone Propionate Other prescribers in Saint Louis, MO | 23 |
| Azelastine Hcl Other prescribers in Saint Louis, MO | 20 |
| Breo Ellipta (fluticasone/vilanterol) Other prescribers in Saint Louis, MO | 19 |
| Albuterol Sulfate Hfa (albuterol sulfate) Other prescribers in Saint Louis, MO | 15 |
| Arnuity Ellipta (fluticasone furoate) Other prescribers in Saint Louis, MO | 14 |
| Fluticasone-Salmeterol (fluticasone propion/salmeterol) Other prescribers in Saint Louis, MO | 13 |
| Budesonide-Formoterol Fumarate (budesonide/formoterol fumarate) Other prescribers in Saint Louis, MO | 13 |
| Ipratropium Bromide Other prescribers in Saint Louis, MO | 11 |
Prescriptions filled under Medicare Part D, including refills. CMS leaves out drugs prescribed fewer than 11 times.
Industry-funded research
Named as a principal investigator on 12 industry-funded studies in 2025, from 7 companies. The companies reported $741,689 in research payments for these studies, mostly to the institutions running them.
- A Study of Lebrikizumab in Adult Participants With Perennial Allergic Rhinitis (PREPARED-1)
Eli Lilly and Company · Active, not recruiting · NCT06339008 - A Phase II, Randomized, Double-blind, Single-dose, Placebo-controlled, 3-Period, 3-Treatment, Crossover, Multicenter Study to Compare the Bronchodilatory Effect and Safety of PT007 AS MDI to Placebo MDI and Open-Label…
AstraZeneca Pharmaceuticals LP - Ph III OLE of Astegolimab in COPD
Genentech, Inc. - A Randomized, Double-Blind, Multicenter, Active-Controlled, Parallel-Group Study to Evaluate the Efficacy and Safety of Fluticasone Propionate/Albuterol Sulfate Fixed-Dose Combination on Severe Asthma Exacerbations in…
Teva Pharmaceuticals USA, Inc. - Ph IIb of Astegolimab in COPD
Genentech, Inc. - Dose Ranging Study of Lunsekimig Compared With Placebo-control in Adult Participants With Moderate-to-severe Asthma
Sanofi US Services Inc. · Completed · NCT06102005 - A phase two a,randomized,double blind,placebo controlled study to assess efficacy and safety of atuliflapon given orally once daily for twelve weeks in adults with moderate to severe uncontrolled asthma
AstraZeneca UK Limited - A Phase IIb Ensifentrine-glycopyrrolate Fixed-dose Combination Dose Ranging Study in Subjects With COPD
Verona Pharma, Inc. - Ph iii study to evaluate the efficacy and safety of astegolimab in copd
Genentech, Inc. - Long-term Safety and Efficacy Evaluation of Lunsekimig (SAR443765) in Adult Participants With Asthma
Sanofi US Services Inc. · Enrolling by invitation · NCT06609239
From CMS Open Payments research payments, where companies name up to five principal investigators per payment. Research payments usually go to hospitals, universities and research sites, not to the investigator personally. A payment is not evidence of wrongdoing.