Maria Kostantacos, APRN, FNP
NPI 1538493614 · Family Nurse Practitioner · Janesville, WI
Enrolled with Medicare as Practitioner - Nurse Practitioner · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Maria Kostantacos, APRN, FNP is a Family Nurse Practitioner provider in Janesville, WI (NPI 1538493614).
Provider details
- NPI number
- 1538493614
- Entity type
- Individual
- Primary specialty
- Family Nurse PractitionerPhysician Assistants & Advanced Practice Nursing Providers
- Credential
- APRN, FNP
- Sex
- Female
- Sole proprietor
- No
- License
- 041343430 (IL)
Specialties & taxonomies
Physician Assistants & Advanced Practice Nursing Providers
Nursing Service Providers
Nursing Service Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
16 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
278 Medicare services, 2024 (ranked within specialty)
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 methodology.
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) |
|---|---|---|
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 35 Minutes99232 | 127 | $65 |
| Subsequent Hospital Care With Straightforward Or Low Level of Medical Decision Making, Per Day, If Using Time, at Least 25 Minutes99231 | 71 | $41 |
| Initial Hospital Care With Straightforward Or Low-Level Medical Decision Making, If Using Time, at Least 55 Minutes99222 | 26 | $103 |
| Initial Hospital Care With Straightforward Or Low Level of Medical Decision Making, Per Day, If Using Time, at Least 40 Minutes99221 | 22 | $67 |
| Hospital Discharge Day Management, 30 Minutes Or Less99238 | 20 | $67 |
| Hospital Discharge Day Management, More Than 30 Minutes99239 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 2 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Oxycodone Hcl | 33 | 29 |
| Amoxicillin/Potassium Clavbrand: Amoxicillin-Clavulanate Potass | 11 | 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.
Practice location
Mailing address
Registry dates
- Enumerated
- 2009-09-23
- Last updated
- 2013-10-02
Frequently asked questions
- What is Maria Kostantacos's NPI number?
- Maria Kostantacos's National Provider Identifier (NPI) is 1538493614, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Maria Kostantacos's specialty?
- Maria Kostantacos is listed in the NPPES registry with a primary specialty of Family Nurse Practitioner (Physician Assistants & Advanced Practice Nursing Providers).
- Where is Maria Kostantacos located?
- Maria Kostantacos's practice location on file with NPPES is 1010 N Washington St, Janesville, WI 53548-1500.
- What is Maria Kostantacos's phone number?
- The practice phone number listed in the NPPES registry for Maria Kostantacos is (608) 741-3800.
- Does Maria Kostantacos accept Medicare?
- Maria Kostantacos is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Maria Kostantacos's NPI active?
- Yes — Maria Kostantacos's NPI (1538493614) is active in the NPPES registry as of the last update on 2013-10-02.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.