Dr. Mark D Johnson , MD PHD
Neurological Surgery โข Worcester, MA
55 Lake Ave N
Worcester, MA 016550002
This profile restates public CMS/NPPES data; T-MedInfo gives no medical advice — consult a licensed professional, and call 911 for emergencies.
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Dr. Mark Johnson is listed in NPPES under Neurological Surgery.
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NPI assigned on June 2, 2006; this date does not establish years in practice.
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Published CMS data list 150 Original Medicare Part B services in 2024.
Source: CMS, Medicare Physician & Other Practitioners โ by Provider and Service, 2024. Published rows only; this is not a quality measure.
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Published Part B service records, 2024:
- 99214 โ Established patient outpatient office visit: 43 service units.
- 99213 โ Established patient outpatient office visit: 36 service units.
- 99215 โ Established patient outpatient office visit: 25 service units.
Source: CMS, Medicare Physician & Other Practitioners โ by Provider and Service, 2024. Units differ by code; these are not visits or a measure of quality.
CPTยฎ only copyright 2023 American Medical Association. All rights reserved. Service names are shortened from CPT Consumer Friendly Descriptors (CMS data, 2024). CPT notice
See all 6 records in the table ยท Guide: How to read Medicare Part B data
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Fewer Medicare Part B services than 60% of clinicians listed under Neurological Surgery in Worcester, MA (2024, 12 clinicians with data). Median for this group: 201. Middle half: 141 to 266.
Fewer Medicare Part B services than 65% of clinicians listed under Neurological Surgery in Massachusetts (2024, 121 clinicians with data). Median for this group: 256. Middle half: 136 to 559.
Source: CMS, Medicare Physician & Other Practitioners โ by Provider and Service, 2024. Billing and prescribing volume is not a quality rating.
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Medicare Part B services went from 179 in 2020 to 150 in 2024.
Source: CMS, Medicare Physician & Other Practitioners โ by Provider and Service, 2020โ2024.
Practice Location & Contact Primary Location
55 Lake Ave N
Worcester, MA 016550002
Matched by practice address or phone in NPPES. A shared address or phone does not confirm that this clinician works there.
CMS Doctors and Clinicians lists 1 group name: Umass Memorial Medical Group Inc. See the list
Source: CMS Doctors and Clinicians National Downloadable File, release date unavailable.
Listings do not confirm current availability, employment or a shared ownership network.
Medicare Profile & Education
Source: CMS Doctors and Clinicians National Downloadable File
Harvard Medical School
1995
What Public CMS Data Show
Neurological Surgery: NPPES taxonomy is a reported classification, not proof of board certification.
Medicare patients
127 people with Original Medicare in 2024
It gives a sense of how many people with Medicare this clinician treated that year.
Source: CMS, Medicare Physician & Other Practitioners โ by Provider, 2024.
Medicare-allowed amount
About $16,686 in 2024
The total amount Medicare approved for these services in 2024. It includes what Medicare paid and what patients or their other insurance owed, such as the deductible and coinsurance.
It shows the total cost of this clinician's Original Medicare services under Medicare's fee rules.
What this does not show: Medicare-allowed amount
This is not the clinician's income. Part of it can go to a clinic or group practice, staff, equipment or drugs. It is not the price you will pay.
Source: CMS, Medicare Physician & Other Practitioners โ by Provider and Service, 2024.
Paid by Medicare
About $13,191 in 2024
The part of the Medicare-allowed amount that Medicare itself paid in 2024, after patients' deductibles and coinsurance.
The gap between the allowed amount and this number is roughly what patients and their other insurance paid.
What this does not show: Paid by Medicare
This is not the clinician's income and not a measure of quality.
Source: CMS, Medicare Physician & Other Practitioners โ by Provider and Service, 2024.
Industry payments (Open Payments)
Fewer than 11 payment records totaling $18.63 in 2025
Drug and medical device companies must report certain payments to doctors and some other clinicians to CMS, such as meals, travel, speaking fees or research funding.
It shows reported financial ties between this clinician and companies. You can ask your clinician about them.
These records are submitted by drug and medical device companies, and a reported payment does not necessarily mean the financial relationship is improper.
General: payments not tied to research, such as meals, travel, consulting or speaking fees.
A reported payment does not necessarily mean the financial relationship is improper. Research payments can go to a hospital or university for a study the clinician leads, not to the clinician personally. Clinicians can dispute records with the company that reported them.
Source: CMS Open Payments, program year 2025.
Years since graduation
31 years (graduated 1995)
CMS Doctors and Clinicians data list 1995 as the year this clinician finished professional school.
It tells you roughly how long ago the clinician finished school.
What this does not show: Years since graduation
It is not the number of years in practice, and more years does not mean better care.
Source: CMS Doctors and Clinicians National Downloadable File.
NPI first issued
2006
The year this clinician's National Provider Identifier (NPI) was issued. An NPI is a unique 10-digit ID that US health care providers use for billing.
What this does not show: NPI first issued
NPIs have been issued only since 2005, so this year is not necessarily when the clinician started practicing.
Source: CMS NPPES NPI Registry.
Accepts Medicare assignment
CMS data list this clinician as accepting Medicare assignment. This means agreeing to take the Medicare-approved amount as full payment for covered services.
With Original Medicare, you usually pay only your deductible and coinsurance, and the office sends the claim to Medicare for you.
Medicare assignment applies to Original Medicare. It does not tell you whether the clinician is in a Medicare Advantage plan's network, accepts other insurance, or is taking new patients.
Source: CMS Doctors and Clinicians; Medicare.gov, โDoes your provider accept Medicare as full payment?โ
Telehealth (some services)
Recent Medicare claims show this clinician provided some services by telehealth, such as a video or phone visit.
You may be able to have some visits without going to the office. Ask which visits can be done by telehealth.
What this does not show: Telehealth (some services)
It does not mean all services are offered by telehealth, or that telehealth is covered by your plan.
Source: CMS, Telehealth Indicator on Medicare Care Compare (fact sheet, January 2023); CMS Doctors and Clinicians.
Enrolled in Medicare (PECOS)
Dr. Johnson has a Medicare enrollment record in PECOS, the CMS system clinicians use to enroll so they can bill Medicare or order services for people with Medicare.
It does not show whether the clinician accepts assignment, is in your plan's network, or is taking new patients.
Source: CMS Medicare Fee-For-Service Public Provider Enrollment (PECOS); CMS Order and Referring file.
Can order Medicare-covered services
CMS lists Dr. Johnson as eligible to order or refer Medicare Part B clinical laboratory and imaging services, durable medical equipment (DME) and home health services for people with Medicare.
Medicare pays for these items and services only when they are ordered by an eligible clinician.
What this does not show: Can order Medicare-covered services
It does not mean the clinician offers these services directly.
Source: CMS Medicare Fee-For-Service Public Provider Enrollment (PECOS); CMS Order and Referring file.
Compared with the same specialty in Worcester and Massachusetts
Billing and prescribing volume is not a quality rating.
Medicare Part B services
Fewer Medicare Part B services than 60% of clinicians listed under Neurological Surgery in Worcester, MA (2024, 12 clinicians with data). Median for this group: 201. Middle half: 141 to 266.
Fewer Medicare Part B services than 65% of clinicians listed under Neurological Surgery in Massachusetts (2024, 121 clinicians with data). Median for this group: 256. Middle half: 136 to 559.
Medicare-allowed amount
A lower Medicare-allowed amount than 60% of clinicians listed under Neurological Surgery in Worcester, MA (2024, 12 clinicians with data). Median for this group: $24,305. Middle half: $13,674 to $38,779.
A lower Medicare-allowed amount than 75% of clinicians listed under Neurological Surgery in Massachusetts (2024, 121 clinicians with data). Median for this group: $47,802. Middle half: $18,804 to $145,436.
Paid by Medicare
A lower Medicare payment amount than 60% of clinicians listed under Neurological Surgery in Worcester, MA (2024, 12 clinicians with data). Median for this group: $18,990. Middle half: $10,645 to $30,166.
A lower Medicare payment amount than 75% of clinicians listed under Neurological Surgery in Massachusetts (2024, 121 clinicians with data). Median for this group: $37,751. Middle half: $14,799 to $114,327.
16 active clinicians are listed under Neurological Surgery with a practice address in Worcester, MA (236 in Massachusetts).
Addresses are self-reported to NPPES and may be out of date.
Telehealth indicator in Worcester
56.2% of these 16 clinicians have the CMS telehealth indicator.
68.8% of these 16 clinicians are listed by CMS as accepting Medicare assignment.
CMS data by year
Changes may reflect reporting, coverage or privacy limits, not changes in care quality.
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Medicare Part B services
Medicare Part B services decreased 16% from 179 in 2020 to 150 in 2024.
- 2020: 179
- 2021: 186
- 2022: 166
- 2023: 131
- 2024: 150
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Medicare-allowed amount
Medicare-allowed amount varied from year to year: $17,214 in 2020 and $16,686 in 2024.
- 2020: $17,214
- 2021: $14,886
- 2022: $15,364
- 2023: $11,876
- 2024: $16,686
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Paid by Medicare
Paid by Medicare varied from year to year: $13,585 in 2020 and $13,191 in 2024.
- 2020: $13,585
- 2021: $11,469
- 2022: $12,063
- 2023: $9,046
- 2024: $13,191
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Industry payments (Open Payments)
Industry payments (Open Payments) went from $19.23 in 2020 to $18.63 in 2025.
- 2020: $19.23
- 2024: $346.92
- 2025: $18.63
Sources: CMS Medicare Physician & Other Practitioners (2024), CMS Open Payments (2025), CMS Doctors and Clinicians, CMS NPPES NPI Registry. Specialty names follow the NUCC Health Care Provider Taxonomy.
Text: T-MedInfo ยท Report an error.
Pharma & Medical Device Financial Disclosures
Payments and other transfers of value that drug and medical device companies reported to CMS Open Payments
Program year 2025 (payments made January 1 โ December 31, 2025): fewer than 11 records totaling $18.63.
| Manufacturer | Payment Nature | Product | Type | Amount ($) |
|---|---|---|---|---|
| DePuy Synthes Sales Inc. |
Food and Beverage
In-kind items and services
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SYNFIX Evolution | General | $18.63 |
Source: CMS Open Payments, program year 2025, released June 30, 2026.
Performed Procedures & Service Volume
CPTยฎ is a registered trademark of the American Medical Association. CPT codes, descriptions and other data only are copyright 2016โ2023 American Medical Association. All rights reserved. Applicable FARS/HHSARS apply. Descriptions of CPT codes are the AMA's CPT Consumer Friendly Descriptors as published by CMS in the Medicare Physician & Other Practitioners โ by Provider and Service data, 2017โ2024; they are plain-language summaries, not for clinical coding or documentation. HCPCS Level II codes and descriptions are from CMS. Fee schedules, relative value units, conversion factors and/or related components are not assigned by the AMA, are not part of CPT, and the AMA is not recommending their use. The AMA does not directly or indirectly practice medicine or dispense medical services. The AMA assumes no liability for data contained or not contained herein.
| HCPCS Code | Services | Patients | Submitted Charge | Medicare Allowed |
|---|---|---|---|---|
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99214
Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more
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43 | 39 | $445.00 | $96.16 |
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99213
Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more
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36 | 30 | $300.00 | $65.29 |
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99215
Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more
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25 | 21 | $625.32 | $142.71 |
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99204
New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more
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21 | 21 | $547.00 | $131.94 |
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61781
Computer-assisted procedure inside brain
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13 | 13 | $1178.00 | $226.98 |
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99203
New patient office or other outpatient visit with low level of medical decision making, if using time, 30 minutes or more
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12 | 12 | $359.00 | $75.99 |
Source: CMS Part B by Provider and Service, 2024; services under 11 beneficiaries omitted by CMS. Privacy limits
Submitted charges are billed amounts, not a price quote for your visit.
Specialties & License Numbers Reported to NPPES
Self-certified to NPPES: 2020-10-26NUCC Taxonomy Code: 207T00000X
A neurological surgeon provides the operative and non-operative management (i.e., prevention, diagnosis, evaluation, treatment, critical care, and rehabilitation) of disorders of the central, peripheral, and autonomic nervous systems, including their supporting structures and vascular supply; the evaluation and treatment of pathological processes which modify function or activity of the nervous system; and the operative and non-operative management of pain. A neurological surgeon treats patients with disorders of the nervous system; disorders of the brain, meninges, skull, and their blood supply, including the extracranial carotid and vertebral arteries; disorders of the pituitary gland; disorders of the spinal cord, meninges, and vertebral column, including those which may require treatment by spinal fusion or instrumentation; and disorders of the cranial and spinal nerves throughout their distribution.
Medicare (PECOS) Enrollment & Ordering Eligibility
Source: CMS PECOSPRACTITIONER - NEUROSURGERY
I20110405000263
MA
9638353360
Sources: CMS Provider Enrollment and Order and Referring. Medicare enrollment is a billing status, not an accreditation or quality rating.
Medicare Group Practice Enrollments
Source: CMS Doctors and Clinicians National Downloadable File
Umass Memorial Medical Group Inc
55 Lake Ave N, Worcester, MA 016550002
Phone: 5083341000
Clinicians Sharing This Practice Address or Phone
Clinicians sharing this NPPES address, phone or fax; a shared contact does not mean they work together.
Nurse Anesthetist, Certified Registered
Certified Registered Nurse Anesthetist
Radiology - Diagnostic Radiology
Dermatology
Medical Genetics - Clinical Genetics (M.D.)
Doctor of Medicine (M.D.)
Nurse Practitioner
Nurse Practitioner
Internal Medicine
Doctor of Medicine (M.D.)
Career & Practice History
NPI enumerated June 02, 2006.
No changes to the name, practice address, taxonomy or NPI status in this record have been observed in the monthly NPPES data files from January 2017 to August 2026.
NPI Administrative Meta
Other Neurological Surgery Specialists in Worcester
- Farid Hamzei-Sichani
- Dr. Peter Amenta, MD
- Dr. Dominic Gessler, MD
- Dr. Celina Crisman, MD
- Dr. Gerald Mcgillicuddy, MD
- Dr. Thomas Pieters, MD
Mailing Address
Po Box 415348
Boston, MA 022415348