NPI registry status
Active
2026 NPPES data Pediatric Allergy/Immunology Physician NPI 1669476495 MD
Verify on CMS → William Johnson, MD
Pediatric Allergy/Immunology Physician in Saint Louis, Missouri.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 422 in Pediatric Allergy/Immunology Physician, and covers specialty classification, practice address, and Medicare Part D prescribing data when reported. According to CMS, every field reflects the provider's official federal registration, see our methodology.
Federal data, no proprietary rating.
We show these CMS records as-is - no composite score, no star rating, no editorial opinion layered on top.
Prescribing volume
1K
Medicare Part D claims · 180 beneficiaries · Pediatric Allergy/Immunology Physician avg: 345
Generic prescribing
56%
generic claims · 44% brand-name · higher generic rates reduce patient out-of-pocket costs
MIPS score
62.3/100
▼ 21 pts below national avg 83.1 · Mid-tier
Industry payments
$175
1 payments · CMS Open Payments (Sunshine Act)
Source: CMS Medicare Part D Prescriber Public Use File, 2023
Compiled from official public sources by the PlainDoctor editorial team.
What the federal data shows
William Johnson, MD reported a CMS MIPS final score of 62.3/100 - below the 83.1 national average - and filed 1,155 Medicare Part D claims in 2023.
- 62.3/100
- MIPS score · -21 vs avg
- 1K
- Part D claims, 2023
- 56%
- generic prescribing
- Likely
- board-certified (heuristic)
Every figure on this page comes straight from federal CMS records (NPPES, Medicare Part D, MIPS, Open Payments) - no proprietary rating or editorial opinion is applied.
William Johnson, MD's MIPS score vs every scored U.S. clinician
CMS Merit-based Incentive Payment System (MIPS) final score, 2023, the federal quality measure
62 6th percentile higher than 6% of 477,587 scored providers
Each bar is a band; taller bars hold more scored providers. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source CMS Merit-based Incentive Payment System (MIPS) · 2023
Where William Johnson, MD sits
This provider among pediatric allergy/immunology physician peers
Across the 42 pediatric allergy/immunology physician providers who report both Medicare Part D prescribing and a MIPS quality score, William Johnson, MD writes more Part D claims than 86% of them and scores higher on MIPS quality than 2% - placing this provider in the high-volume, lower-quality quadrant. Volume reflects patient-panel size and specialty, not quality; the two axes are independent.
Part D claim volume vs MIPS quality, by specialty percentile
Each dot is one pediatric allergy/immunology physician peer from a representative sample of 41; the gold marker is William Johnson, MD. Source: CMS Medicare Part D Prescriber data and the CMS Merit-based Incentive Payment System, 2023.
✓
Board certification likely (heuristic, not verified)
William Johnson, MD practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + MIPS quality reporting - signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).
What does the federal data show about William Johnson, MD?
Below national averagePrimary specialty
Pediatric Allergy/Immunology Physician
Medicare Part D claims
1,155 235% vs specialty avg
MIPS final score
62.3/100 20.8 pts vs avg
Specialty distribution in Missouri
How Pediatric Allergy/Immunology Physician compares to other specialties among Missouri providers
Medicare quality performance, MIPS
William Johnson, MD's 2023 MIPS final score plotted against the Pediatric Allergy/Immunology Physician national average
- MIPS Final Score
- 62.3/100
- vs 83.1 national avg · 2023 performance year
MIPS final score (Pediatric Allergy/Immunology Physician) - 62.3/100 vs national avg 83.1
How MIPS and board certification work
The Merit-based Incentive Payment System (MIPS) scores providers 0–100 across four performance categories: Quality, Cost, Promoting Interoperability, and Improvement Activities, weighted under 42 CFR §414.1380. Reporting is voluntary for many small practices, so absence of a MIPS score is not a quality signal.
Board certification through an ABMS or AOA member board signals voluntary post-licensure examination plus continuous Maintenance of Certification cycles. Verify any individual provider's status through certificationmatters.org (ABMS) or osteopathic.org (AOA).
William Johnson, MD appears in the CMS NPPES registry as a Pediatric Allergy/Immunology Physician provider holding MD credentials at 1 CHILDRENS PL, Saint Louis, MO, 63110, with a listed phone of (314) 454-2694. NPI 1669476495 was issued on 06/09/2005.
Medicare Part D records for calendar year 2023 show 1,155 prescription claims written by this provider, covering 180 Medicare beneficiaries and totaling roughly $362K in drug spend, split 44% brand-name and 56% generic by claim count. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 62.3/100 for the 2023 performance year (Quality 19.4, Cost 69.9), compared with the national average of 83.1.
Pediatric Allergy/Immunology Physician is a narrow specialty nationwide, with 422 enrolled providers across 43 states and an average of 345 Part D claims per prescriber, so the context for interpreting these metrics differs meaningfully from a primary-care baseline.
Important: PlainDoctor is a directory of publicly available government data, not medical advice, a malpractice database, or a quality rating. Inclusion here does not imply a recommendation, and absence of complaints or sanctions on this page does not mean none exist, always verify credentials through the NPPES NPI Registry, your state medical board, and the ABMS or AOA before making healthcare decisions.
Practice Address
Provider Details
| NPI | 1669476495 |
|---|---|
| Specialty | Pediatric Allergy/Immunology Physician |
| Credentials | MD |
| Gender | Male |
| NPI Issued | 06/09/2005 |
CMS Quality Score (MIPS)
Merit-based Incentive Payment System (MIPS) scores from CMS, 2023 performance year.
62.2853
Final Score
Avg: 83.1
19.3968
Quality
69.8876
Cost
82
Promoting Interoperability
Reporting: Group practice
Industry payments received (2024) - CMS Open Payments transparency data
The federal Physician Payments Sunshine Act (part of the Affordable Care Act) requires drug and medical-device manufacturers + group purchasing organizations to publicly report payments and other transfers of value to physicians and teaching hospitals. The data below covers 2024 for William Johnson, MD. Source: openpaymentsdata.cms.gov.
Total received
$175
Largest payer
AIMMUNE THERAPEUTICS, INC.
Most common payment type
Honoraria
Industry payments are not necessarily indicators of bias, they include research funding, consulting fees for evidence-based work, royalties for inventions, food at conferences, and similar items. The disclosure exists for transparency. Read our methodology for how we interpret this data.
Brand vs generic prescribing mix · Above average
William Johnson, MD - brand share 44.0%
Pediatric Allergy/Immunology Physician average
44% brand-name claims vs 56% generic, on 1,155 2023 Medicare Part D claims.
The federal Medicare Part D Generic Dispensing Rate national benchmark sits near 90% generic / 10% brand for primary-care prescribers, per CMS Office of the Actuary 2024 estimates. Higher brand share is common in specialty prescribing where generic equivalents are not available.
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2023.
1,155
Total Claims
$362K
Total Drug Cost
180
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 2,076
- Total Day Supply
- 59,949
- Brand vs Generic
- 44% brand / 56% generic
- Brand Drug Cost
- $335K
- Generic Drug Cost
- $27K
- Antibiotic Claims
- 15
Patient Demographics
- Average Patient Age
- 71.2 years
- Avg HCC Risk Score
- 1.12
- Gender Split
- 68% female / 32% male
- Age Distribution
- <65: 19, 65-74: 101, 75-84: 49, 85+: 11
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What William Johnson, MD prescribes most
Top Medicare Part D drugs by claim count, 2023
- Montelukast Sodium
Montelukast Sodium
155 claims
- Fluticasone Propio…
Fluticasone Propionate
105 claims
- Azelastine Hcl
Azelastine Hcl
99 claims
- Albuterol Sulfate …
Albuterol Sulfate Hfa
98 claims
- Trelegy Ellipta
Trelegy Ellipta
92 claims
- Symbicort
Symbicort
82 claims
- Breo Ellipta
Breo Ellipta
72 claims
- Ipratropium Bromide 50
Ipratropium Bromide
50 claims
| Drug | Claims |
|---|---|
| Montelukast Sodium | 155 |
| Fluticasone Propionate | 105 |
| Azelastine Hcl | 99 |
| Albuterol Sulfate Hfa Albuterol Sulfate | 98 |
| Trelegy Ellipta Fluticasone/Umeclidin/Vilanter | 92 |
| Symbicort Budesonide/Formoterol Fumarate | 82 |
| Breo Ellipta Fluticasone/Vilanterol | 72 |
| Ipratropium Bromide | 50 |
| Omeprazole | 42 |
| Wixela Inhub Fluticasone Propion/Salmeterol | 42 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
More Pediatric Allergy/Immunology Physician in MO →
All providers in Missouri →
Compare specialties →
Pediatric Allergy/Immunology Physician Overview
How William Johnson, MD fits within the Pediatric Allergy/Immunology Physician landscape nationally.
422
Pediatric Allergy/Immunology Physician Providers in US
43
States with Pediatric Allergy/Immunology Physician
345
Avg Claims per Provider
William Johnson, MD's 1,155 claims are above the specialty average of 345.
Nearby Pediatric Allergy/Immunology Physician Providers in Missouri
Other clinicians with the same primary specialty enrolled in Missouri, drawn from the same CMS NPPES roster as Johnson.
Dr. Salman Aljubran
MD
Kansas City, MO
Dr. Maggie Barnthouse
MD
Kansas City, MO
Dr. Gordon Bloomberg
MD
Saint Louis, MO
Dr. Ray Davis
MD
Saint Louis, MO
Dr. Paul Dowling
M.D.
Kansas City, MO
Compare Pediatric Allergy/Immunology Physician nationally: see state-by-state distribution →
Before you book an appointment
Use this federal record as your verification checklist, not as a recommendation.
- Confirm the NPI record is current in the official CMS registry, providers update their own NPPES details, and moves can lag. Verify this NPI
- Check the active license and any disciplinary history with the Missouri medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Pediatric Allergy/Immunology Physician peer on Medicare volume and prescribing patterns. Compare providers
Medicare Part D and MIPS figures describe practice patterns in federal programs only, they are not quality ratings, and PlainDoctor does not rate, rank, or recommend providers.
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Frequently Asked Questions
What is William Johnson, MD's specialty? ▼
William Johnson, MD specializes in Pediatric Allergy/Immunology Physician and practices in Saint Louis, Missouri. Credentials: MD.
How much does William Johnson, MD prescribe under Medicare Part D? ▼
In 2023, William Johnson, MD wrote 1,155 Medicare Part D claims totaling $362K in drug costs for 180 beneficiaries.
What is William Johnson, MD's Medicare quality score? ▼
William Johnson, MD has a CMS MIPS Final Score of 62.3/100 (Quality: 19.4, Cost: 69.9). The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is William Johnson, MD located? ▼
William Johnson, MD is located at 1 CHILDRENS PL, Saint Louis, MO, 63110. Phone: (314) 454-2694.
What is William Johnson, MD's NPI number? ▼
William Johnson, MD's National Provider Identifier (NPI) is 1669476495, issued on 06/09/2005.
Does William Johnson, MD prescribe more brand-name or generic drugs? ▼
William Johnson, MD's prescribing is 44% brand-name and 56% generic drugs by claim count, with $335K in brand drug costs.
How many Pediatric Allergy/Immunology Physician providers are there in the US? ▼
There are 422 Pediatric Allergy/Immunology Physician providers across 43 states in the US. The average Pediatric Allergy/Immunology Physician provider writes 345 Medicare Part D claims per year.
What drugs does William Johnson, MD prescribe most often? ▼
Based on 2023 Medicare Part D data, William Johnson, MD's most frequently prescribed drugs include Montelukast Sodium, Fluticasone Propionate, Azelastine Hcl. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does William Johnson, MD accept Medicare? ▼
William Johnson, MD appears in CMS Medicare data with 1,155 Part D claims and 180 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify William Johnson, MD's credentials? ▼
William Johnson, MD's NPI is 1669476495 with credentials MD. You can verify this through the NPPES NPI Registry, check state medical board records, and confirm board certification through the ABMS or AOA.
Data Sources
View source datasets and methodology notes
- Provider Directory
- CMS National Plan and Provider Enumeration System (NPPES), download.cms.gov/nppes, updated monthly. Contains NPI, specialty, credentials, and practice location.
- Specialty Classification
- NUCC Health Care Provider Taxonomy (nucc.org), the industry standard for classifying provider specialties in Medicare and Medicaid billing.
- Prescribing Data
- CMS Medicare Part D Prescriber Public Use File (2023). Includes claims, drug costs, beneficiaries, and opioid prescribing rates.
- Quality Performance
- CMS Merit-based Incentive Payment System (MIPS) - 2023 performance year.
- Limitations
- Provider data is self-reported to CMS. Prescribing data reflects Medicare Part D only and does not include commercial insurance, Medicaid, or cash prescriptions. Claims below 11 beneficiaries are suppressed by CMS for privacy.
See our complete data methodology for details on how we collect and process government data.
Data as of April 2026 (NPPES) / 2023 (Medicare Part D). Source: Centers for Medicare & Medicaid Services (CMS).
Disclaimer: Data from CMS NPPES and Medicare Part D. PlainDoctor does not rate or rank providers. Provider information is self-reported and may not be current. Always verify information directly with the provider. About · Methodology
Compiled from official public sources by the PlainDoctor editorial team.
Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of May 2026.