Nathan Tonlaar, M.D.
NPI 1811284375 · Radiation Oncology Physician · Springfield, MO
Enrolled with Medicare as Practitioner - Radiation Oncology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Nathan Tonlaar, M.D. is a Radiation Oncology Physician provider in Springfield, MO (NPI 1811284375).
Provider details
- NPI number
- 1811284375
- Entity type
- Individual
- Primary specialty
- Radiation Oncology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- 4301099423 (MI)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
14 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
1,449 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our .
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Ct Guidance for Insertion of Radiation Therapy Fields77014 | 618 | $41 |
| Design and Construction of Complex Radiation Treatment Device77334 | 162 | $56 |
| Radiation Treatment Management, 5 Treatment Sessions77427 | 146 | $176 |
| Calculation of Radiation Therapy Dose77300 | 126 | $30 |
| Complex Radiation Therapy Planning77263 | 70 | $154 |
| New Patient Office Or Other Outpatient Visit With a High Level of Medical Decision Making, If Using Time, 60 Minutes Or More99205 | 58 | $169 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 5 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Hydrocodone/Acetaminophenbrand: Hydrocodone-Acetaminophen | 65 | 65 |
| Levofloxacin | 65 | 65 |
| Diazepam | 44 | 44 |
| Prednisone | 26 | 20 |
| Tamsulosin Hcl | 17 | 11 |
Medicare Part D only. These counts cover prescriptions paid through Medicare Part D in 2024 — they do notinclude cash-pay, commercial-insurance, Medicaid, or Part B–administered drugs, and badly undercount high cash-pay categories (e.g. GLP-1 weight-loss, testosterone, and ED medications). Any drug with 10 or fewer claims is omitted by CMS, and beneficiary counts under 11 are suppressed — so a missing drug means no Part D record, never zero. This is a factual claims summary, not an endorsement, not medical advice, and not a consumer report. Source: CMS Medicare Part D Prescribers — by Provider and Drug.
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$414 across 5 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2011-07-06
- Last updated
- 2016-06-02
Frequently asked questions
- What is Nathan Tonlaar's NPI number?
- Nathan Tonlaar's National Provider Identifier (NPI) is 1811284375, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Nathan Tonlaar's specialty?
- Nathan Tonlaar is listed in the NPPES registry with a primary specialty of Radiation Oncology Physician (Allopathic & Osteopathic Physicians).
- Where is Nathan Tonlaar located?
- Nathan Tonlaar's practice location on file with NPPES is 2055 S Fremont Ave, Springfield, MO 65804-2206.
- What is Nathan Tonlaar's phone number?
- The practice phone number listed in the NPPES registry for Nathan Tonlaar is (417) 820-2468.
- Does Nathan Tonlaar accept Medicare?
- Nathan Tonlaar is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Nathan Tonlaar's NPI active?
- Yes — Nathan Tonlaar's NPI (1811284375) is active in the NPPES registry as of the last update on 2016-06-02.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.