Quick answers
- Does Guillermo A. Mendoza Fonseca accept Medicare assignment?
- Yes. Medicare's clinician data says Guillermo A. Mendoza Fonseca 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 Guillermo A. Mendoza Fonseca see?
- In 2024, CMS data shows 76 Original Medicare patients and 1,172 services for Guillermo A. Mendoza Fonseca. This counts Original Medicare only and measures volume, not quality.
- What is Guillermo A. Mendoza Fonseca's NPI number?
- 1285898288. 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 Guillermo A. Mendoza Fonseca, 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 | 76 |
|---|---|
| Services billed to Medicare | 1,172 |
| Different services or procedures | 27 |
| Participating Medicare provider | Yes |
| Average age of these patients | 74 |
Most frequent services
- Chronic care management services, first 20 minutes of clinical staff time directed by health care professional, per calendar month (99490)243 services
- Management using the results of remote vital sign monitoring per calendar month, first 20 minutes (99457)242 services
- Remote monitoring of physiologic parameters, initial supply of devices with daily recordings or programmed alerts transmission, each 30 days (99454)235 services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)95 services
- Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)65 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 blood pressure75%
- High cholesterol75%
- Diabetes51%
- Arthritis47%
- Chronic kidney disease45%
- Ischemic heart disease36%
Hospitals where Guillermo A. Mendoza Fonseca works
Medicare's Facility Affiliation Data lists Guillermo A. Mendoza Fonseca 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.
- AdventHealth OrlandoOrlando, FL · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 100007
Practice locations
Addresses where Guillermo A. Mendoza Fonseca is enrolled with Medicare (CMS data updated October 2, 2026).
- 1200 Lexington Green LnSanford, FL 32771
- 2572 W State Rd, 426 Suite 3040Oviedo, FL 32765 (407) 890‑9748
Group practices
Medicare enrollment lists Guillermo A. Mendoza Fonseca as a member of these groups (CMS data updated October 2, 2026).
- Ability Health Services and Rehabilitation LP1,269 clinicians in the group
- Ability Health Services, Inc1,258 clinicians in the group
Specialties
- Internal Medicineprimary
Other internal medicine doctors in Sanford
Clinicians with the same Medicare primary specialty in Sanford, FL — not a recommendation.
Other clinicians in Ability Health Services and Rehabilitation LP
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 2001 (25 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1285898288 |
| 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