Quick answers
- Does Alissa K. O'Brien accept Medicare assignment?
- Yes. Medicare's clinician data says Alissa K. O'Brien 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 Alissa K. O'Brien see?
- In 2024, CMS data shows 1,508 Original Medicare patients and 8,532 services for Alissa K. O'Brien. This counts Original Medicare only and measures volume, not quality.
- What is Alissa K. O'Brien's NPI number?
- 1538394960. 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 Alissa K. O'Brien, 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 | 1,508 |
|---|---|
| Services billed to Medicare | 8,532 |
| Different services or procedures | 75 |
| Participating Medicare provider | Yes |
| Average age of these patients | 75 |
Most frequent services
- Destruction of precancer skin growth, 2-14 growths (17003)2,141 services
- Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)1,627 services
- Destruction of precancer skin growth, 1 growth (17000)1,107 services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)900 services
- Biopsy of related skin growth, first growth (11102)791 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%
- High blood pressure64%
- Arthritis44%
- Ischemic heart disease29%
- Osteoporosis23%
- Anxiety21%
Practice locations
Addresses where Alissa K. O'Brien is enrolled with Medicare (CMS data updated October 2, 2026).
- 261 9th St SNaples, FL 34102 (239) 216‑4337
Group practices
Medicare enrollment lists Alissa K. O'Brien as a member of this group (CMS data updated October 2, 2026).
- Aqua Dermatology of Florida, PA187 clinicians in the group
Specialties
- Dermatologyprimary
- Internal Medicinealso
Other dermatologists in Naples
Clinicians with the same Medicare primary specialty in Naples, FL — not a recommendation.
Other clinicians in Aqua Dermatology of Florida, PA
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Florida College Of Medicine |
| Graduation year | 2009 (17 years since medical school) |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1538394960 |
| 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