Quick answers
- Does Jessica L. Underhill accept Medicare assignment?
- Yes. Medicare's clinician data says Jessica L. Underhill accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
- How many Medicare patients does Jessica L. Underhill see?
- In 2024, CMS data shows 173 Original Medicare patients and 450 services for Jessica L. Underhill. This counts Original Medicare only and measures volume, not quality.
- What is Jessica L. Underhill's NPI number?
- 1417362880. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Medicare activity in 2024
Official CMS public-use data for Jessica L. Underhill, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.
| Original Medicare patients | 173 |
|---|---|
| Services billed to Medicare | 450 |
| Different services or procedures | 19 |
| Participating Medicare provider | Yes |
| Average age of these patients | 72 |
Most frequent services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)205 services
- Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit (G0439)115 services
- Visit complexity inherent to evaluation and management associated with medical care services that serve as the continuing focal point for all needed health care services and/or with medical care services that are part of ongoing care related to a patient's (G2211)34 services
- Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)33 services
- Initial preventive physical examination; face-to-face visit, services limited to new beneficiary during the first 12 months of medicare enrollment (G0402)12 services
Chronic conditions among these patients
Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).
- High cholesterol71%
- High blood pressure69%
- Arthritis35%
- Chronic kidney disease35%
- Diabetes30%
- Anxiety29%
Hospitals where Jessica L. Underhill works
Medicare's Facility Affiliation Data lists Jessica L. Underhill at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.
- Barnes-Jewish St Peters HospitalSaint Peters, MO · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 260191
- SSM St Joseph Health CenterSaint Charles, MO · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 260005
- SSM St Joseph Hospital WestLake Saint Louis, MO · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 260200
Practice locations
Addresses where Jessica L. Underhill is enrolled with Medicare (CMS data updated October 2, 2026).
- 6994 Mexico RdSaint Peters, MO 63376 (636) 397‑3231
- 7212 Balson AveSaint Louis, MO 63130
Group practices
Medicare enrollment lists Jessica L. Underhill as a member of these groups (CMS data updated October 2, 2026).
- SSM Medical Group Inc568 clinicians in the group
- Aging Well Health Care, LLC238 clinicians in the group
Specialties
- Family Practiceprimary
Other family doctors in Saint Peters
Clinicians with the same Medicare primary specialty in Saint Peters, MO — not a recommendation.
Other clinicians in SSM Medical Group Inc
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | DO |
|---|---|
| Graduation year | 2014 (12 years since medical school) |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1417362880 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
- Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians