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DR. MARK WILLIAM JENNINGS M.D.
NPI 1396124988
Anesthesiology in Boston, MA

Active since May 28, 2015PECOS EnrolledAccepts Medicare Assignment
133 SEAPORT BLVD UNIT 1819, BOSTON, MA 02210(607) 426-8112 Get Directions Write a Review

NPPES record last updated: January 3, 2022. Verified against the NPPES registry weekly; last sync: October 18, 2026.

Record update history: Jan 3, 2022, Jan 7, 2019 (2 updates tracked since 2019).

About Dr. Mark William Jennings M.d. NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. MARK WILLIAM JENNINGS M.D. (NPI 1396124988) is an individual anesthesiology provider in Boston, Massachusetts, licensed in Massachusetts (290324) and active in the NPI registry since May 2015. He is enrolled in Medicare PECOS and is a graduate of Eastern Virginia Medical School (2015).

NPPES Registry Identity

NPI1396124988
Entity TypeIndividualMale
Primary Taxonomy207L00000X
Provider Legal NameDR. MARK WILLIAM JENNINGSCredential: M.D.
Location Address133 SEAPORT BLVD UNIT 1819Boston, MA 02210-2674
Mailing Address133 Seaport Blvd Unit 1819Boston, MA 02210-2674
Phone(607) 426-8112
Sole ProprietorNo
Medical School CMSEastern Virginia Medical SchoolGraduated 2015
Enumeration DateMay 28, 2015
Last NPPES UpdateJanuary 3, 20222 updates tracked since enumeration
NPPES CertifiedJanuary 3, 2022
✔ NPI 1396124988 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyAnesthesiologyAllopathic & Osteopathic Physicians
Taxonomy Code207L00000X
Licenses✔ Licensed in MA · 290324✔ Licensed in HI · 20085
Definition
An anesthesiologist is trained to provide pain relief and maintenance, or restoration, of a stable condition during and immediately following an operation or an obstetric or diagnostic procedure. The anesthesiologist assesses the risk of the patient undergoing surgery and optimizes the patient's condition prior to, during and after surgery. In addition to these management responsibilities, the anesthesiologist provides medical management and consultation in pain management and critical care medicine. Anesthesiologists diagnose and treat acute, long-standing and cancer pain problems; diagnose and treat patients with critical illnesses or severe injuries; direct resuscitation in the care of patients with cardiac or respiratory emergencies, including the need for artificial ventilation; and supervise post-anesthesia recovery.
133 SEAPORT BLVD UNIT 1819, Boston, MA 02210
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Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Dr. Mark William Jennings M.d. is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID6002143658
PECOS Enrollment IDI20220129000005
Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Medicare Billing Reassignments

2

Medicare enrollment records show Mark Jennings reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Jjm Medical Services, PC
12 mi
Anesthesiology
1440 MAIN ST
Waltham, MA 02451
  • Reassigned Medicare billing, Massachusetts enrollment
  • 90 clinicians in this Medicare group
NPI 1952548265 (781) 891-9300
North Shore Ambulatory Anesthesia Partners LLC
14 mi
Anesthesiology
1 ORTHOPEDICS DR
Peabody, MA 01960
  • Reassigned Medicare billing, Massachusetts enrollment
  • 14 clinicians in this Medicare group
NPI 1821535378 (978) 818-6500

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Areas of Expertise CMS Part B claims 7

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Anesthesia for lens surgery 00142
Anesthesia for lens surgery involves administering medication to numb the eye area, ensuring you feel no pain during the procedure. This can be a local anesthetic (numbing only the eye area) or general (where you're asleep). It helps make the surgery comfortable and stress-free.
277 services272 patients
Anesthesia for injection, drainage or aspiration procedures on spine or spinal cord of lower back accessed through skin using imaging guidance 01938
This procedure involves using anesthesia to numb your lower back for certain procedures like injections, drainage, or aspiration on your spine or spinal cord. Imaging guidance is used to accurately locate the area to be treated, ensuring precision and safety.
47 services45 patients
Anesthesia for other procedure on eye 00140
Anesthesia for an eye procedure involves administering medication to numb your eye and surrounding area, ensuring you feel no pain during the operation. It can be local (only the eye area) or general (whole body). It's safe and helps make the procedure comfortable.
31 services30 patients
Anesthesia for other procedure on large bowel using an endoscope 00811
Anesthesia for an endoscopic procedure on the large bowel ensures comfort and relaxation during the procedure. You'll be given medication to make you drowsy or asleep, eliminating any discomfort. The medication can be administered through a vein or inhaled.
28 services28 patients
Anesthesia for procedure on nerves, muscles, tendons, and tissue of forearm, wrist, and hand 01810
Anesthesia for procedures on the forearm, wrist, and hand involves administering medication to block sensation in these areas. This helps ensure comfort and painlessness during surgeries or treatments involving nerves, muscles, tendons, and tissue in these regions.
25 services25 patients
Anesthesia for exam of colon using an endoscope 00812
Anesthesia for a colon examination with an endoscope is a method used to ensure comfort during the procedure. It involves administering medication to help you relax or sleep, thus reducing discomfort as the endoscope, a thin, flexible tube, is navigated through your colon.
20 services20 patients

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Mark Jennings's NPI number?

The NPI number for Mark Jennings is 1396124988. It was assigned to this individual provider in the NPPES registry on May 28, 2015.

Where is Mark Jennings located?

Mark Jennings practices at 133 Seaport Blvd Unit 1819, Boston, MA 02210. The listed phone number is (607) 426-8112.

What is Mark Jennings's specialty?

The primary specialty registered for this NPI is Anesthesiology with taxonomy code 207L00000X.

Is Mark Jennings enrolled in Medicare?

Yes. Mark Jennings is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

Which organizations bill Medicare for Mark Jennings's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Mark Jennings reassigns Medicare benefits to 2 organizations: Jjm Medical Services, PC (Waltham, MA) and North Shore Ambulatory Anesthesia Partners LLC (Peabody, MA). Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Mark Jennings's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

When was this NPI record last updated?

The NPPES record for Mark Jennings was last updated on January 3, 2022. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 4 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.