Mary Parker Johnstone
- Part D claims, 2024
- 223
- MIPS score, 2024
- 91
- Hospital affiliations
- 2
- Industry payments
- $208
- Medical groups
- 3
- Practice address
- 800 Washington Street, Boston, MA 02111
- Practice phone
- Call (617) 636-5000
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Find Mary Johnstone's 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.
Mary Parker Johnstone is a physician assistant in Boston, Massachusetts
Mary Johnstone practices at Tufts Medical Center in Boston, Massachusetts, part of Tufts Medicine.
Mary Johnstone's NPI, 1639810807, was assigned on April 5, 2022. Mary Johnstone graduated from University of Tennessee, Hsc, College of Medicine in 2021. Mary Johnstone holds Massachusetts license PA9335.
- NPI
- 1639810807NPI Registry (opens in a new tab)
- Medicare PAC ID
- 8527455484
- NPI enumeration date
- April 5, 2022
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Offers telehealth
- Yes
- Practice phone
- (617) 636-5000
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Female
- Estimated age
- 31
- Medical school graduation
- 2021
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Mary Parker Johnstone practices at Tufts Medical Center in Boston, Massachusetts
Mary Johnstone's primary practice is Tufts Medical Center, at 800 Washington Street, Boston, MA 02111 in Suffolk County. The practice phone is (617) 636-5000.
- Tufts Medical Center800 Washington Street, Boston, MA 02111 · Suffolk CountyPhone(617) 636-5000
Source: Dmand AI Affiliation Data
Mary Parker Johnstone is affiliated with 4 sites of care and 3 medical groups
Mary Johnstone's primary practice is Tufts Medical Center in Boston, Massachusetts, part of Tufts Medicine. Mary Johnstone is also affiliated with CHA Cambridge Hospital. The medical group on file is Pratt Medical Group, Inc. - General Medical Associates (General Internal Medicine). Dmand AI also links Mary Johnstone to 2 more medical groups, 1 imaging center and 1 ambulatory surgery center, each named with a free account.
Sources: Dmand AI Affiliation Data; and Dmand AI Org Hierarchy Data
Dmand AI tracks the EHR system at Mary Parker Johnstone's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Mary Johnstone practices, 4 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Tufts Medical Center | Available with a free account |
| +3 more sites and 2 medical groups | Available with a free account |
Source: Dmand AI Technology Install Data
For health IT teams
Dmand AI maps EHR vendors, IT decision makers and buying committees across Tufts Medicine and 6.2K+ hospitals, with verified contacts in the same login.
Mary Parker Johnstone is one of 3,922 physician assistants in Massachusetts
Physician assistant is Mary Johnstone's primary specialty in the NPI Registry, under taxonomy code 363A00000X. Dmand AI has Mary Johnstone's licenses on file in 2 states: Massachusetts and Tennessee.
Specialties and state licenses
- Physician assistant, MassachusettsPrimary
- Orthopaedic surgery, Tennessee
Physician assistants near Mary Johnstone
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
Mary Parker Johnstone's patients have a median age of 39
Across all payers, Dmand AI patient panel data puts Mary Johnstone's median patient age at 39, with 57% women.
Mary Johnstone's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 39
Patient panel by sex, all payers
- Women57%
- Men42%
Source: Dmand AI Patient Panel Data
Mary Parker Johnstone wrote 223 Medicare Part D claims in 2024
In 2024, Mary Johnstone wrote 223 Medicare Part D claims for 181 patients. 71% of them were for generic drugs.
Mary Johnstone's Part D claims by kind of drug, 2024
- Generic158 claims71%
- Brand-name65 claims29%
Source: Medicare Part D Prescribers - by Provider (CMS), 2024 data
Mary Parker Johnstone scored 91 out of 100 in Medicare's MIPS program for 2024
CMS publishes a Merit-based Incentive Payment System (MIPS) score of 91 out of 100 for Mary Johnstone for performance year 2024, reported as part of a group. Mary Johnstone accepts Medicare assignment, so Medicare's approved amount is taken as full payment. CMS lists Mary Johnstone as offering telehealth.
- Accepts Medicare assignment
- Yes
- Offers telehealth
- Yes
Mary Johnstone's MIPS scores, performance year 2024
- 91of 100Final score
- 77.5of 100Quality
- 100of 100Promoting Interoperability
- 40of 100Improvement Activities
- 77of 100Cost
Each score is out of 100. The final score weighs the categories CMS scored for this clinician.
Sources: Doctors and Clinicians National Downloadable File (CMS); and Clinician Public Reporting: Overall MIPS Performance (CMS), 2024 data, released September 10, 2026
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Filter 7.4M+ HCPs by Medicare procedures, Part D drugs and Open Payments history, then reach them with verified contacts in one login.
Mary Parker Johnstone received $208 in industry payments in 2025
CMS Open Payments shows 2 general payments to Mary Johnstone from 1 drug or device company in 2025. Food and beverage make up the largest share, 100% of the total. Janssen Pharmaceuticals, Inc paid the most, $208.
Companies that paid Mary Johnstone the most, 2025 to 2025
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Mary Parker Johnstone graduated from University of Tennessee, Hsc, College of Medicine
Mary Johnstone graduated from University of Tennessee, Hsc, College of Medicine in 2021.
- Medical school
Source: Dmand AI Professional Profile Data
Sources for Mary Parker Johnstone'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 Data |
| Part D prescribing | Medicare Part D Prescribers - by Provider (CMS) (opens in a new tab) |
| MIPS scores, telehealth, assignment and procedure percentiles | Doctors and Clinicians National Downloadable File (CMS) (opens in a new tab)Clinician Public Reporting: Overall MIPS Performance (CMS) (opens in a new tab) |
| Industry payments | Open Payments (CMS) (opens in a new tab) |
| Training, board certification and memberships | Dmand AI Professional Profile Data |
| 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 Mary Parker Johnstone
Spotted something out of date? Email hello@dmand.ai and we will check the record. Contact details live in the free trial.
What is Mary Parker Johnstone's NPI number?
Mary Parker Johnstone's NPI number is 1639810807. It was assigned on April 5, 2022, and it is active in the NPI Registry.
What does Mary Parker Johnstone specialize in?
Mary Parker Johnstone is a physician assistant in Boston, Massachusetts. The primary specialty in the NPI Registry is Physician Assistant (taxonomy code 363A00000X).
Where does Mary Parker Johnstone practice?
Mary Johnstone practices at 800 Washington Street, Boston, MA 02111. Mary Johnstone's primary practice is Tufts Medical Center in Boston, Massachusetts, part of Tufts Medicine. Dmand AI also links Mary Johnstone to 2 medical groups, 1 imaging center and 1 ambulatory surgery center.
What is Mary Parker Johnstone's office phone number?
The practice phone on file for Mary Johnstone is (617) 636-5000.
What is Mary Parker Johnstone's medical license number?
Mary Johnstone holds Massachusetts license PA9335, one of the licenses on file in 2 states.
Which states has Mary Parker Johnstone been licensed in?
Dmand AI has state licenses on file for Mary Johnstone in Massachusetts and Tennessee.
Which hospitals is Mary Parker Johnstone affiliated with?
Mary Johnstone practices at Tufts Medical Center in Boston, Massachusetts. Mary Johnstone is also affiliated with CHA Cambridge Hospital.
What medical group is Mary Parker Johnstone part of?
Mary Johnstone is linked to Pratt Medical Group, Inc. - General Medical Associates (General Internal Medicine). Dmand AI links Mary Johnstone to 2 more medical groups.
Does Mary Parker Johnstone accept Medicare?
Yes. CMS lists Mary Johnstone as accepting Medicare assignment.
Does Mary Parker Johnstone offer telehealth?
Yes. The CMS Doctors and Clinicians file lists Mary Johnstone as offering telehealth services.
Show 4 more questionsShow fewer questions
What is Mary Parker Johnstone's MIPS score?
Mary Johnstone's MIPS final score for performance year 2024 is 91 out of 100, reported as part of a group.
Where did Mary Parker Johnstone go to medical school?
Mary Johnstone graduated from University of Tennessee, Hsc, College of Medicine in 2021.
Has Mary Parker Johnstone received payments from drug or device companies?
CMS Open Payments shows $208 in general payments to Mary Johnstone from 1 company from 2025 to 2025. The largest total came from Janssen Pharmaceuticals, Inc.
How long has Mary Parker Johnstone been practicing?
Mary Johnstone graduated from medical school in 2021, 5 years ago.
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