Marissa Ontis, FNP-C
NPI 1629704929 · Family Nurse Practitioner · Alton, IL
Enrolled with Medicare as Practitioner - Nurse Practitioner · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Marissa Ontis, FNP-C is a Family Nurse Practitioner provider in Alton, IL (NPI 1629704929).
Provider details
- NPI number
- 1629704929
- Entity type
- Individual
- Primary specialty
- Family Nurse PractitionerPhysician Assistants & Advanced Practice Nursing Providers
- Credential
- FNP-C
- Sex
- Female
- Sole proprietor
- No
- License
- 209025582 (IL)
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 tenure25% of score
3 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
1,244 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) |
|---|---|---|
| Removal of Fingernails Or Toenails, 6 Or More Nails11721 | 876 | $20 |
| Removal of Fingernails Or Toenails, 6 Or More Nails11721 | 150 | $36 |
| Established Patient Office Or Other Outpatient Visit With Straightforward Medical Decision Making, If Using Time, 10 Minutes Or More99212 | 70 | $30 |
| New Patient Office Or Other Outpatient Visit With Low Level of Medical Decision Making, If Using Time, 30 Minutes Or More99203 | 50 | $70 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 41 | $55 |
| Initial Nursing Facility Care With Moderate Level of Medical Decision Making, Per Day, If Using Time, at Least 35 Minutes99305 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 4 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Gabapentin | 37 | — |
| Ammonium Lactate | 18 | — |
| Doxycycline Hyclate | 16 | 14 |
| Terbinafine Hcl | 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.
$16 across 1 record (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
- 2022-07-28
- Last updated
- 2026-05-01
- Certified
- 2026-05-01
Frequently asked questions
- What is Marissa Ontis's NPI number?
- Marissa Ontis's National Provider Identifier (NPI) is 1629704929, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Marissa Ontis's specialty?
- Marissa Ontis is listed in the NPPES registry with a primary specialty of Family Nurse Practitioner (Physician Assistants & Advanced Practice Nursing Providers).
- Where is Marissa Ontis located?
- Marissa Ontis's practice location on file with NPPES is 1 Memorial Dr # G181, Alton, IL 62002-6755.
- What is Marissa Ontis's phone number?
- The practice phone number listed in the NPPES registry for Marissa Ontis is (618) 433-7066.
- Does Marissa Ontis accept Medicare?
- Marissa Ontis is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Marissa Ontis's NPI active?
- Yes — Marissa Ontis's NPI (1629704929) is active in the NPPES registry as of the last update on 2026-05-01.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.