NPI registry status
Active
2026 NPPES data Gastroenterology Physician NPI 1639168685 M.D.
Verify on CMS → Thomas Johnson, M.D.
Gastroenterology Physician in Nevada, Iowa.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 17,061 in Gastroenterology 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
2K
Medicare Part D claims · 824 beneficiaries · Gastroenterology Physician avg: 848
Industry payments
$25.37
1 payments · CMS Open Payments (Sunshine Act)
What the federal data shows
Thomas Johnson, M.D. filed 2,081 Medicare Part D claims in 2024 as a Gastroenterology Physician in Nevada, Iowa.
- 2K
- Part D claims, 2024
- $25.37
- industry payments (Sunshine Act)
- ≥84th
- pct by Part D claim volume (lower-bound band)
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.
Federal trust snapshot
What official records show about Thomas Johnson, M.D.
Federal records show an active NPI with Medicare Part D prescribing activity — verifiable registry data, not a proprietary rating.
- Verified
NPI registry status
Active listing in the CMS National Provider Identifier Registry (NPI 1639168685), first enumerated 10/20/2005.
Source: CMS NPPES
- Reported
Medicare Part D participation
Filed 2,081 Medicare Part D prescription claims in the 2023 CMS public use file — indicates active Medicare prescribing participation.
Source: CMS Part D Prescriber PUF
- Reported
Board certification signal
Practices in an ABMS-board-eligible specialty; board certification not confirmed in federal records.
- Reported
Industry payment transparency
$25.37 in reported industry payments (1 transfers) in 2024 under the federal Sunshine Act — disclosed transfers of value, not a quality rating.
Source: CMS Open Payments
- Not in federal data
Individual sanction lookup
PlainDoctor does not publish per-provider disciplinary determinations. Confirm current license and any individual actions through the state medical board or FSMB verification service.
Source: State medical board / FSMB
This trust snapshot summarizes only what appears in federal CMS/NPPES public records. It is not a composite score, star rating, patient review, or clinical recommendation. PlainDoctor never fabricates reviews or AggregateRating schema.
CMS NPPES provider registry desk
NPI 1639168685 · Gastroenterology Physician
NPI-10 · ENUM-LEGACY · TAX-MID · RX-MID · BOOK-THIN · PHOTO-ENUM
- NPI-10 1639168685
- ENUM-LEGACY 2005
- TAX-MID 17K Gastroenterology Physician
- RX-MID 2,081
- BOOK-THIN 84 in Iowa
- PHOTO-ENUM Gloria Diaz · 2005
Thomas Johnson, M.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2024, across all CMS prescribers nationally
2,081 ≥ 84th percentile 84% of 1,416,883 prescribers are in lower value bands
Each bar is a band; taller bars hold more prescribers. 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.
The percentile is a conservative 100-claim band: it counts only prescribers in lower claim-volume bands. Medicare Part D claim volume is activity context, not a quality measure or recommendation. See methodology § corpus placement.
Source CMS Medicare Part D Prescriber Public Use File · 2024
◑
Board-eligible specialty (heuristic, not verified)
Thomas Johnson, M.D. practices in an ABMS-board-eligible specialty but we don't have enough CMS-participation signals to confirm active board-certified status. Consult CertificationMatters.org (the official ABMS public lookup).
What does the federal data show about Thomas Johnson, M.D.?
Quality data not reportedPrimary specialty
Gastroenterology Physician
Medicare Part D claims
2,081 145% vs specialty avg
Specialty distribution in Iowa
How Gastroenterology Physician compares to other specialties among Iowa providers
Board certification
Not published by CMS
CMS does not publish a per-provider board-certification field in NPPES. PlainDoctor does not have a reliable per-specialty certification rate to show for Gastroenterology Physician. Verify directly:
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).
Practice Address
Provider Details
| NPI | 1639168685 |
|---|---|
| Specialty | Gastroenterology Physician |
| Credentials | M.D. |
| Gender | Male |
| NPI Issued | 10/20/2005 |
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 Thomas Johnson, M.D.. Source: openpaymentsdata.cms.gov.
Total received
$25
Largest payer
ShockWave Medical, Inc
Most common payment type
Food and Beverage
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.
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2024.
2,081
Total Claims
$340K
Total Drug Cost
824
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 2,961.233
- Total Day Supply
- 68,983
- Generic Drug Cost
- $131K
- Antibiotic Claims
- 21
Patient Demographics
- Average Patient Age
- 72.7 years
- Avg HCC Risk Score
- 1.02
- Gender Split
- 59% female / 41% male
- Age Distribution
- <65: 39, 65-74: 468, 75-84: 280, 85+: 37
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2024. Based on Medicare Part D data only.
What Thomas Johnson, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2024
- Sod Sulf-Potass Su…
Sod Sulf-Potass Sulf-Mag Sulf
492 claims
- Omeprazole 190
Omeprazole
190 claims
- Colestipol Hcl 179
Colestipol Hcl
179 claims
- Balsalazide Disodium 143
Balsalazide Disodium
143 claims
- Budesonide Dr 118
Budesonide Dr
118 claims
- Gavilyte-G 96
Gavilyte-G
96 claims
- Ursodiol 93
Ursodiol
93 claims
- Azathioprine 92
Azathioprine
92 claims
| Drug | Claims |
|---|---|
| Sod Sulf-Potass Sulf-Mag Sulf Sodium, Potassium,mag Sulfates | 492 |
| Omeprazole | 190 |
| Colestipol Hcl | 179 |
| Balsalazide Disodium | 143 |
| Budesonide Dr Budesonide | 118 |
| Gavilyte-G Peg3350/Sod Sulf,bicarb,cl/Kcl | 96 |
| Ursodiol | 93 |
| Azathioprine | 92 |
| Pantoprazole Sodium | 53 |
| Linzess Linaclotide | 47 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Gastroenterology Physician Overview
How Thomas Johnson, M.D. fits within the Gastroenterology Physician landscape nationally.
17,061
Gastroenterology Physician Providers in US
54
States with Gastroenterology Physician
848
Avg Claims per Provider
Thomas Johnson, M.D.'s 2,081 claims are above the specialty average of 848.
Nationwide Gastroenterology Physician peers with similar MIPS or enrollment year
Two federal-record peer sets for Johnson, both outside Iowa so the neighborhoods are not geographic containment.
Same NPPES enumeration year (2005)
Same-specialty clinicians who entered the NPI registry in the same calendar year, outside this state.
Nearby Gastroenterology Physician Providers in Iowa
Other clinicians with the same primary specialty enrolled in Iowa, drawn from the same CMS NPPES roster as Johnson.
One of 84 Gastroenterology Physician providers enrolled in Iowa, 5 are shown here.
Dr. Tyler Aasen
D.O.
West Des Moines, IA
Dr. Abdillahi Abdinoor
MD
Clive, IA
Dr. Barakat Aburajab Altamimi
M.D.
Cedar Rapids, IA
Dr. Amol Agarwal
MD
Clive, IA
Dr. Naurang Agrawal
MD
Iowa City, IA
Compare Gastroenterology Physician nationally: see state-by-state distribution →
Frequently Asked Questions
What is Thomas Johnson, M.D.'s specialty? ▼
Thomas Johnson, M.D. specializes in Gastroenterology Physician and practices in Nevada, Iowa. Credentials: M.D..
How much does Thomas Johnson, M.D. prescribe under Medicare Part D? ▼
In 2024, Thomas Johnson, M.D. wrote 2,081 Medicare Part D claims totaling $340K in drug costs for 824 beneficiaries.
Where is Thomas Johnson, M.D. located? ▼
Thomas Johnson, M.D. is located at 1102 DAKOTA CT, Nevada, IA, 50201. Phone: (515) 296-2041.
What is Thomas Johnson, M.D.'s NPI number? ▼
Thomas Johnson, M.D.'s National Provider Identifier (NPI) is 1639168685, issued on 10/20/2005.
How many Gastroenterology Physician providers are there in the US? ▼
There are 17,061 Gastroenterology Physician providers across 54 states in the US. The average Gastroenterology Physician provider writes 848 Medicare Part D claims per year.
What drugs does Thomas Johnson, M.D. prescribe most often? ▼
Based on 2024 Medicare Part D data, Thomas Johnson, M.D.'s most frequently prescribed drugs include Sod Sulf-Potass Sulf-Mag Sulf, Omeprazole, Colestipol Hcl. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Thomas Johnson, M.D. accept Medicare? ▼
Thomas Johnson, M.D. appears in CMS Medicare data with 2,081 Part D claims and 824 Medicare beneficiaries in 2024. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Thomas Johnson, M.D.'s credentials? ▼
Thomas Johnson, M.D.'s NPI is 1639168685 with credentials M.D.. 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 (2024). Includes claims, drug costs, beneficiaries, and opioid prescribing rates.
- 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 August 2026 (NPPES) / 2024 (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
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 August 2026.