Mary Onderdonk, DNP, CRNP
NPI 1245802156 · Gerontology Nurse Practitioner · Towson, MD
Enrolled with Medicare as Practitioner - Nurse Practitioner · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mary Onderdonk, DNP, CRNP is a Gerontology Nurse Practitioner provider in Towson, MD (NPI 1245802156).
Provider details
- NPI number
- 1245802156
- Entity type
- Individual
- Primary specialty
- Gerontology Nurse PractitionerPhysician Assistants & Advanced Practice Nursing Providers
- Credential
- DNP, CRNP
- Sex
- Female
- Sole proprietor
- No
- License
- R234428 (MD)
Specialties & taxonomies
Physician Assistants & Advanced Practice Nursing Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
4 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
1 documented practice location
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 methodology.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 1 distinct drug on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Haloperidol | 18 | 16 |
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.
Practice location
Mailing address
Registry dates
- Enumerated
- 2021-07-12
- Last updated
- 2021-08-30
- Certified
- 2021-08-30
Frequently asked questions
- What is Mary Onderdonk's NPI number?
- Mary Onderdonk's National Provider Identifier (NPI) is 1245802156, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mary Onderdonk's specialty?
- Mary Onderdonk is listed in the NPPES registry with a primary specialty of Gerontology Nurse Practitioner (Physician Assistants & Advanced Practice Nursing Providers).
- Where is Mary Onderdonk located?
- Mary Onderdonk's practice location on file with NPPES is 6701 N Charles St Ste 4105, Towson, MD 21204-6808.
- What is Mary Onderdonk's phone number?
- The practice phone number listed in the NPPES registry for Mary Onderdonk is (443) 849-6255.
- Does Mary Onderdonk accept Medicare?
- Mary Onderdonk is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mary Onderdonk's NPI active?
- Yes — Mary Onderdonk's NPI (1245802156) is active in the NPPES registry as of the last update on 2021-08-30.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.