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MRS. MARISSA ANNE ONTIS FNP-C
NPI 1629704929
Nurse Practitioner - Family in Alton, IL

Active since July 28, 2022PECOS EnrolledAccepts Medicare Assignment
1 MEMORIAL DR # G181, ALTON, IL 62002(618) 433-7066(618) 433-7060 Get Directions Write a Review

NPPES record last updated: May 1, 2026. Verified against the NPPES registry weekly; last sync: October 25, 2026.

Record update history: May 1, 2026, Nov 13, 2024, Sep 16, 2024 and 3 more (6 updates tracked since 2022).

About Mrs. Marissa Anne Ontis Fnp-c NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

MRS. MARISSA ANNE ONTIS FNP-C (NPI 1629704929) is an individual family provider in Alton, Illinois, licensed in Illinois (209025582) and active in the NPI registry since July 2022. She is enrolled in Medicare PECOS, is affiliated with Alton Memorial Hospital, and is a graduate of Other (2022).

NPPES Registry Identity

NPI1629704929
Entity TypeIndividualFemale
Primary Taxonomy363LF0000X
Provider Legal NameMRS. MARISSA ANNE ONTISCredential: FNP-C
Location Address1 MEMORIAL DR # G181Alton, IL 62002-6755
Mailing Address1 Memorial Dr # G-181Alton, IL 62002-6722 · (618) 433-4066 · Fax (618) 433-7060
Phone(618) 433-7066
Fax(618) 433-7060
Sole ProprietorNo
Medical School CMSOtherGraduated 2022
Enumeration DateJuly 28, 2022
Last NPPES UpdateMay 1, 20266 updates tracked since enumeration
NPPES CertifiedMay 1, 2026
✔ NPI 1629704929 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyNurse Practitioner · FamilyPhysician Assistants & Advanced Practice Nursing Providers
Taxonomy Code363LF0000X
License✔ Licensed in IL · 209025582
1 MEMORIAL DR # G181, Alton, IL 62002
Open in Google Maps ↗

Other Names 1

Former Name (1)Marissa Anne Delp

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Ambetter Health, Ambetter Health of Delaware.Insurance ›

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Mrs. Marissa Anne Ontis Fnp-c is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID446636955
PECOS Enrollment IDI20221007000155
Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Medicare Billing Reassignments

2

Medicare enrollment records show Marissa Ontis reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Healogics Specialty Physicians Of Illinois, LLC
Same address
Undersea and Hyperbaric Medicine
1 MEMORIAL DR
Alton, IL 62002
  • Reassigned Medicare billing, Illinois enrollment
  • 39 clinicians in this Medicare group
NPI 1215355110 (616) 433-7066
Healogics Specialty Physicians Of Missouri, LLC
269 mi
Undersea and Hyperbaric Medicine
1905 W 32ND ST STE 103
Joplin, MO 64804
  • Reassigned Medicare billing, Missouri enrollment
  • 22 clinicians in this Medicare group
NPI 1528468311 (904) 446-3451

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Areas of Expertise CMS Part B claims 7

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Removal of fingernails or toenails, 6 or more nails 11721
This procedure involves the removal of six or more fingernails or toenails. It's typically done to treat severe nail infections, persistent pain, or abnormal nail growth. Local anesthesia is used to minimize discomfort. Healing usually takes a few weeks.
876 services353 patients
Removal of fingernails or toenails, 6 or more nails 11721
This procedure involves the removal of six or more fingernails or toenails. It's typically done to treat severe nail infections, persistent pain, or abnormal nail growth. Local anesthesia is used to minimize discomfort. Healing usually takes a few weeks.
150 services83 patients
Established patient office or other outpatient visit with straightforward medical decision making, if using time, 10 minutes or more 99212
This is a routine check-up for patients who have previously seen the doctor. During this 10-19 minute visit, the doctor will review your health status, discuss any concerns, and manage ongoing treatments or medications. It's a chance to ensure your health is on track.
70 services58 patients
New patient office or other outpatient visit with low level of medical decision making, if using time, 30 minutes or more 99203
This service involves an initial office or outpatient visit for a new patient. The healthcare professional will spend 30-44 minutes understanding your health history, current issues, and discussing possible treatment plans. It's a comprehensive evaluation to start your healthcare journey.
50 services50 patients
Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more 99213
This is a routine visit for patients who have already been seen by the healthcare provider. During this approximately 20-29 minute appointment, your health status will be evaluated and any necessary treatments or tests will be discussed. It's a chance to address any health concerns you may have.
41 services40 patients
Initial nursing facility care with moderate level of medical decision making, per day, if using time, at least 35 minutes 99305
An initial nursing facility visit per day is a service where a healthcare professional spends about 35 minutes assessing a patient's health status. This includes reviewing medical history, conducting a physical exam, and developing a care plan based on the patient's needs.
33 services33 patients

Hospital Affiliations CMS Care Compare 4

Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.

Alton Memorial Hospital

Acute Care Hospitals · Alton, IL
4/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number140002
LocationOne Memorial DriveAlton, IL 62002 · Madison County
Emergency services Birthing friendly

Osf Saint Anthony's Health Center

Acute Care Hospitals · Alton, IL
2/5 CMS rating
OwnershipVoluntary non-profit - Church
CMS Certification Number140052
LocationSt Anthony's WayAlton, IL 62002 · Madison County

Memorial Hospital

Acute Care Hospitals · Belleville, IL
4/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number140185
Location4500 Memorial DriveBelleville, IL 62226 · St. Clair County
Emergency services Birthing friendly

Barnes Jewish Hospital

Acute Care Hospitals · Saint Louis, MO
4/5 CMS rating
OwnershipVoluntary non-profit - Other
CMS Certification Number260032
LocationOne Barnes-Jewish Hospital PlazaSaint Louis, MO 63110 · St. Louis City County
Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 62002 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$88.44 typical visit price
range $56.28 – $173.35
Typical copayment $22.11 (range $14.07 – $43.33)
Most-billed visit code 99203
Established Patient
$99.71 typical visit price
range $17.51 – $139.99
Typical copayment $24.92 (range $4.37 – $34.99)
Most-billed visit code 99214
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Marissa Ontis's NPI number?

The NPI number for Marissa Ontis is 1629704929. It was assigned to this individual provider in the NPPES registry on July 28, 2022. The provider is also known as Marissa Anne Delp.

Where is Marissa Ontis located?

Marissa Ontis practices at 1 Memorial Dr # G181, Alton, IL 62002. The listed phone number is (618) 433-7066.

What is Marissa Ontis's specialty?

The primary specialty registered for this NPI is Nurse Practitioner, specializing in Family, with taxonomy code 363LF0000X.

Is Marissa Ontis enrolled in Medicare?

Yes. Marissa Ontis is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

Which organizations bill Medicare for Marissa Ontis's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Marissa Ontis reassigns Medicare benefits to 2 organizations: Healogics Specialty Physicians Of Illinois, LLC (Alton, IL) and Healogics Specialty Physicians Of Missouri, LLC (Joplin, MO). Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Marissa Ontis's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Marissa Ontis accept?

Health plans from Ambetter Health and Ambetter Health of Delaware list Marissa Ontis as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.

Is Marissa Ontis affiliated with any hospitals?

According to CMS data, Marissa Ontis is affiliated with Alton Memorial Hospital, Osf Saint Anthony's Health Center, Memorial Hospital and Barnes Jewish Hospital.

When was this NPI record last updated?

The NPPES record for Marissa Ontis was last updated on May 1, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 5 months ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.