Quick answers
- Does Marieliz V. Alonso Calderon accept Medicare assignment?
- Yes. Medicare's clinician data says Marieliz V. Alonso Calderon 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 Marieliz V. Alonso Calderon see?
- In 2024, CMS data shows 157 Original Medicare patients and 689 services for Marieliz V. Alonso Calderon. This counts Original Medicare only and measures volume, not quality.
- What is Marieliz V. Alonso Calderon's NPI number?
- 1295990018. 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 Marieliz V. Alonso Calderon, 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 | 157 |
|---|---|
| Services billed to Medicare | 689 |
| Different services or procedures | 6 |
| Participating Medicare provider | Yes |
| Average age of these patients | 73 |
Most frequent services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)629 services
- Psychiatric diagnostic evaluation with medical services (90792)42 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 cholesterol75%
- Anxiety75%
- Depression72%
- High blood pressure64%
- Arthritis52%
- Diabetes29%
Practice locations
Addresses where Marieliz V. Alonso Calderon is enrolled with Medicare (CMS data updated October 2, 2026).
- 8221 Willow Oaks Corporate DrFairfax, VA 22031 (703) 289‑7560
- 8505 Arlington BlvdFairfax, VA 22031
Group practices
Medicare enrollment lists Marieliz V. Alonso Calderon as a member of this group (CMS data updated October 2, 2026).
- Inova Health Care Services1,817 clinicians in the group
Specialties
- Geriatric Psychiatryprimary
- Psychiatryalso
Other geriatric psychiatrists in Virginia
Clinicians with the same Medicare primary specialty in Virginia — not a recommendation.
Other clinicians in Inova Health Care Services
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | New York Medical College |
| Graduation year | 2008 (18 years since medical school) |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1295990018 |
| 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
- 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