Marissa L. Williams, PA-C
- Medicare patients, 2024
- 28
- Part D claims, 2024
- 5,344
- Hospital affiliations
- 3
- Industry payments
- $357
- Medical groups
- 3
- Practice address
- 7050 Gall Blvd, Zephyrhills, FL 33541
- Practice phone
- Call (813) 615-7219
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Find Marissa Williams' professional email, personal email and mobile number
Dmand AI checks each channel through healthcare-specific waterfall enrichment. See what is on file with a free account, with practice phones, licenses and affiliations.
Marissa L. Williams is a physician assistant in Zephyrhills, Florida
Marissa Williams practices at AdventHealth Zephyrhills in Zephyrhills, Florida, part of AdventHealth.
Marissa Williams' NPI, 1851688873, was assigned on June 29, 2011. Marissa Williams holds Florida license PA9106109.
- NPI
- 1851688873NPI Registry (opens in a new tab)
- Medicare PAC ID
- 7618126392
- NPI enumeration date
- June 29, 2011
- NPI status
- Active
- Practice phone
- (813) 615-7219
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Female
- Estimated age
- 41
- Medical school graduation
- 2011
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Affiliation Data
Marissa L. Williams practices at AdventHealth Zephyrhills in Zephyrhills, Florida
Marissa Williams' primary practice is AdventHealth Zephyrhills, at 7050 Gall Blvd, Zephyrhills, FL 33541 in Pasco County. The practice phone is (813) 615-7219.
- AdventHealth Zephyrhills7050 Gall Blvd, Zephyrhills, FL 33541 · Pasco CountyPhone(813) 615-7219
Source: Dmand AI Affiliation Data
Marissa L. Williams is affiliated with 6 sites of care and 3 medical groups
Marissa Williams' primary practice is AdventHealth Zephyrhills in Zephyrhills, Florida, part of AdventHealth. Marissa Williams is also affiliated with AdventHealth Tampa. The medical group on file is Legacy Healthcare Services. Dmand AI also links Marissa Williams to 1 more hospital, 2 group practices and clinics, 2 medical groups and 1 home health agency, each named with a free account.
Sources: Dmand AI Affiliation Data; and Dmand AI Org Hierarchy Data
Dmand AI tracks the EHR system at Marissa L. Williams' practice
Dmand AI tracks the electronic health record (EHR) system at each site where Marissa Williams practices, 6 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| AdventHealth Zephyrhills | Available with a free account |
| +5 more sites and 2 medical groups | Available with a free account |
Source: Dmand AI Technology Install Data
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Marissa L. Williams is one of 7,899 physician assistants in Florida
Physician assistant is Marissa Williams' primary specialty in the NPI Registry, under taxonomy code 363A00000X. Marissa Williams is licensed in Florida.
Specialties and state licenses
- Physician assistant, FloridaPrimary
Physician assistants near Marissa Williams
Counts of physician assistants with a Dmand AI profile, by place and practice. Each opens the list.
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Peer Benchmarks
Marissa L. Williams treated 28 Medicare patients in 2024, average age 76
CMS counts 28 Medicare patients who saw Marissa Williams in 2024. 75% of them have high blood pressure, and 75% have high cholesterol. Their average risk score is 1.23, where 1.00 is the Medicare average.
Across all payers, Dmand AI patient panel data puts Marissa Williams' median patient age at 67, with 71% women.
Chronic conditions among Marissa Williams' Medicare patients, 2024
- High blood pressure75%
- High cholesterol75%
- Arthritis50%
- Chronic kidney disease39%
- Diabetes39%
Share of Medicare patients with each condition. A patient can have several.
Marissa Williams' patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 67
Patient panel by sex, all payers
- Women71%
- Men28%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Marissa L. Williams wrote 5,344 Medicare Part D claims in 2024
In 2024, Marissa Williams wrote 5,344 Medicare Part D claims for 389 patients. 82% of them were for generic drugs.
Marissa Williams' Part D claims by kind of drug, 2024
- Generic4,408 claims82%
- Brand-name923 claims17%
- Other13 claims0%
Drug classes CMS tracks in Marissa Williams' Part D claims, 2024
- Antibiotics5%269 of 5,344 claims
- Antipsychotics, patients 65 and over1%31 of 5,344 claims
Share of all Part D claims for each drug class CMS reports on. Classes with no claims are left out.
Source: Medicare Part D Prescribers - by Provider (CMS), 2024 data
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Marissa L. Williams received $357 in industry payments in 2025
CMS Open Payments shows 20 general payments to Marissa Williams from 6 drug and device companies in 2025. Food and beverage make up the largest share, 100% of the total. Novo Nordisk Inc paid the most, $89.
Companies that paid Marissa Williams the most, 2025 to 2025
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Sources for Marissa L. Williams's profile data
| Data on this page | Source |
|---|---|
| NPI, name, sex, specialty and licenses | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Professional Profile Data |
| Practice locations and phone | Dmand AI Affiliation Data |
| Primary practice, affiliations and health system | Dmand AI Affiliation DataDmand AI Org Hierarchy Data |
| Medicare patients and the all-payer patient panel | Dmand AI Patient Panel DataMedicare Physician & Other Practitioners - by Provider (CMS) (opens in a new tab) |
| Part D prescribing | Medicare Part D Prescribers - by Provider (CMS) (opens in a new tab) |
| Industry payments | Open Payments (CMS) (opens in a new tab) |
| EHR at each practice site | Dmand AI Technology Install Data |
| Similar physicians | Dmand AI Affiliation Data |
Data last refreshed October 2026Report an inaccuracyRemove my information
FAQ
Frequently asked questions about Marissa L. Williams
Spotted something out of date? Email hello@dmand.ai and we will check the record. Contact details live in the free trial.
What is Marissa L. Williams' NPI number?
Marissa L. Williams' NPI number is 1851688873. It was assigned on June 29, 2011, and it is active in the NPI Registry.
What does Marissa L. Williams specialize in?
Marissa L. Williams is a physician assistant in Zephyrhills, Florida. The primary specialty in the NPI Registry is Physician Assistant (taxonomy code 363A00000X).
Where does Marissa L. Williams practice?
Marissa Williams practices at 7050 Gall Blvd, Zephyrhills, FL 33541. Marissa Williams' primary practice is AdventHealth Zephyrhills in Zephyrhills, Florida, part of AdventHealth. Dmand AI also links Marissa Williams to 1 hospital, 2 group practices and clinics, 2 medical groups and 1 home health agency.
What is Marissa L. Williams' office phone number?
The practice phone on file for Marissa Williams is (813) 615-7219.
What is Marissa L. Williams' medical license number?
Marissa Williams holds Florida license PA9106109, one of 2 state licenses on file.
Which hospitals is Marissa L. Williams affiliated with?
Marissa Williams practices at AdventHealth Zephyrhills in Zephyrhills, Florida. Marissa Williams is also affiliated with AdventHealth Tampa. Dmand AI links Marissa Williams to 1 more hospital.
What medical group is Marissa L. Williams part of?
Marissa Williams is linked to Legacy Healthcare Services. Dmand AI links Marissa Williams to 2 more medical groups.
How many Medicare patients does Marissa L. Williams see?
CMS counts 28 Medicare patients who saw Marissa Williams in 2024, with an average age of 76.
Has Marissa L. Williams received payments from drug or device companies?
CMS Open Payments shows $357 in general payments to Marissa Williams from 6 companies from 2025 to 2025. The largest total came from Novo Nordisk Inc.
How long has Marissa L. Williams been practicing?
Marissa Williams graduated from medical school in 2011, 15 years ago.
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