1. Home
  2. Directory
  3. Massachusetts
  4. Dedham
  5. Internal Medicine
  6. NPI Profile

CLAES M NILSSON MD
NPI 1912006065
Internal Medicine in Dedham, MA

Active since September 22, 2006PECOS EnrolledAccepts Medicare Assignment
990 WASHINGTON ST, SUITE 203, DEDHAM, MA 02026(413) 543-6820(781) 326-1384 Get Directions Write a Review

NPPES record last updated: October 19, 2022. Verified against the NPPES registry weekly; last sync: October 25, 2026.

About Claes M Nilsson Md NPPES

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

CLAES M NILSSON MD (NPI 1912006065) is an individual internal medicine provider in Dedham, Massachusetts, licensed in Massachusetts (53091) and active in the NPI registry since September 2006. He is enrolled in Medicare PECOS and is a graduate of Yale University School Of Medicine (1973).

NPPES Registry Identity

NPI1912006065
Entity TypeIndividualMale
Primary Taxonomy207R00000X
Provider Legal NameCLAES M NILSSONCredential: MD
Location Address990 WASHINGTON ST, SUITE 203Dedham, MA 02026-6714
Mailing Address819 Worcester St, Ste 3Springfield, MA 01151-1045 · (413) 543-6820 · Fax (413) 543-7962
Phone(413) 543-6820
Fax(781) 326-1384
Sole ProprietorNo
Medical School CMSYale University School Of MedicineGraduated 1973
Enumeration DateSeptember 22, 2006
Last NPPES UpdateOctober 19, 2022
NPPES CertifiedOctober 18, 2022
✔ NPI 1912006065 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
License✔ Licensed in MA · 53091
Definition
A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.
990 WASHINGTON ST, Dedham, MA 02026
Open in Google Maps ↗

Other Identifiers 1

Medicaid110045324/AMA

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Taro Health, WellSense Health Plan.Insurance ›

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

Claes M Nilsson Md 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 ID2365435351
PECOS Enrollment IDI20040406000501
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

3

Medicare enrollment records show Claes Nilsson reassigns Medicare billing to 3 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Vantage Healthcare LLC
4.8 mi
Internal Medicine
C/O WORKPLACE@45, 45 DAN RD
Canton, MA 02021
  • Reassigned Medicare billing, Massachusetts enrollment
  • 113 clinicians in this Medicare group
NPI 1366903551 (781) 867-2050
Massachusetts Acute Care Specialists PC
17 mi
Internal Medicine
585 LEBANON ST
Melrose, MA 02176
  • Reassigned Medicare billing, Massachusetts enrollment
  • 176 clinicians in this Medicare group
NPI 1306134812 (781) 979-3000
Ipc Hospitalists Of New England, P.C.
68 mi
Internal Medicine
819 WORCESTER ST STE 3
Springfield, MA 01151
  • Reassigned Medicare billing, Massachusetts enrollment
  • Medicare enrollment name: Ipc Hospitalists Of New England PC
  • 124 clinicians in this Medicare group
NPI 1932516176 (413) 543-6820

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.

Subsequent nursing facility care with straightforward level of medical decision making, per day, if using time, 20 minutes or more 99308
A follow-up nursing facility visit per day is a daily check-up service provided by healthcare professionals. It lasts around 15 minutes and involves assessing your health status, monitoring your recovery progress, and addressing any concerns you may have about your health or treatment.
427 services254 patients
Residence visit for established patient with low level of medical decision making, per day, if using time, at least 30 minutes 99348
An established patient home visit is a 25-minute appointment where a healthcare provider visits you at your home. This service is for patients who have previously been seen by the provider. It includes a check-up and discussion about your health concerns.
209 services103 patients
Subsequent nursing facility care with moderate level of medical decision making, per day, if using time, at least 30 minutes 99309
A follow-up nursing facility visit per day is a daily check-in by a healthcare professional. This 25-minute visit typically involves monitoring your health progress, addressing any concerns, and adjusting treatment plans as necessary. It's a vital part of ensuring your ongoing wellbeing.
85 services68 patients
Residence visit for established patient with moderate level of medical decision making, per day, if using time, at least 40 minutes 99349
An established patient home visit is a medical appointment conducted at your home, typically lasting around 40 minutes. This service is ideal for patients who may find it difficult to travel to a healthcare facility. During this visit, a healthcare professional will evaluate your health status, manage your care, and answer any health-related questions you may have.
44 services37 patients
Initial nursing facility care with moderate level of medical decision making, per day, if using time, at least 35 minutes 99305
An initial nursing facility visit per day is a service where a healthcare professional spends about 35 minutes assessing a patient's health status. This includes reviewing medical history, conducting a physical exam, and developing a care plan based on the patient's needs.
28 services27 patients
Residence visit for established patient with straightforward medical decision making, per day, if using time, at least 15 minutes 99347
An established patient home visit is a service where a healthcare professional visits your home for a 15-minute check-up. It's designed for patients who have previously seen the professional. The visit may include basic health assessments and discussions about your ongoing care.
28 services28 patients

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 02026 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$144.11 typical visit price
range $63.72 – $189.86
Typical copayment $36.02 (range $15.93 – $47.46)
Most-billed visit code 99204
Established Patient
$111.18 typical visit price
range $21.07 – $155.29
Typical copayment $27.79 (range $5.26 – $38.82)
Most-billed visit code 99214
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Referred Medical Equipment & Supplies CMS DME claims 9

Durable medical equipment, devices and supplies this provider ordered from DME suppliers for patients, from Medicare fee-for-service claims.

Insertion tray with drainage bag with indwelling catheter, foley type, two-way latex with coating (teflon, silicone, silicone elastomer or hydrophilic, etc.) A4314
DME-Orthotic Devices · category DF000N
1 supplier12 claims12 services$19.23 avg. paid by Medicare
Urinary catheter anchoring device, leg strap, each A4334
DME-Orthotic Devices · category DF000N
1 supplier11 claims11 services$3.93 avg. paid by Medicare
Bedside drainage bag, day or night, with or without anti-reflux device, with or without tube, each A4357
DME-Orthotic Devices · category DF000N
1 supplier15 claims20 services$7.66 avg. paid by Medicare
Alginate or other fiber gelling dressing, wound cover, sterile, pad size 16 sq. in. or less, each dressing A6196
DME-Medical/Surgical Supplies · category DA023N
1 supplier11 claims780 services$6.46 avg. paid by Medicare
Composite dressing, sterile, pad size 16 sq. in. or less, with any size adhesive border, each dressing A6203
DME-Medical/Surgical Supplies · category DA023N
1 supplier14 claims720 services$2.76 avg. paid by Medicare
Enteral feeding supply kit; pump fed, per day, includes but not limited to feeding/flushing syringe, administration set tubing, dressings, tape B4035
Other-Enteral and Parenteral · category OB006N
1 supplier11 claims310 services$4.26 avg. paid by Medicare
Dollar amounts are the average Medicare paid the supplier per service. They are not the cost to the patient.

Other Providers at the Same Location NPPES 3

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

NANCY BOUFFARD NURSE PRACTITIONER
Nurse Practitioner (Adult Health)
990 WASHINGTON ST, UNIT 203
DEDHAM, MA 02026
Norfolk County (781) 404-7041
MR. ETHAN M FIELD LICSW
Social Worker (Clinical)
990 WASHINGTON ST, SUITE 209
DEDHAM, MA 02026
Norfolk County (781) 329-4774
MRS. JUDITH BELLEVUE NP
Nurse Practitioner
990 WASHINGTON ST
DEDHAM, MA 02026
Norfolk County (781) 404-7045

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 Claes Nilsson's NPI number?

The NPI number for Claes Nilsson is 1912006065. It was assigned to this individual provider in the NPPES registry on September 22, 2006.

Where is Claes Nilsson located?

Claes Nilsson practices at 990 Washington St Suite 203, Dedham, MA 02026. The listed phone number is (413) 543-6820.

What is Claes Nilsson's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Is Claes Nilsson enrolled in Medicare?

Yes. Claes Nilsson 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 Claes Nilsson's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Claes Nilsson reassigns Medicare benefits to 3 organizations: Vantage Healthcare LLC (Canton, MA), Massachusetts Acute Care Specialists PC (Melrose, MA) and Ipc Hospitalists Of New England, P.C. (Springfield, 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 Claes Nilsson's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Claes Nilsson accept?

Health plans from Taro Health and WellSense Health Plan list Claes Nilsson as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.

When was this NPI record last updated?

The NPPES record for Claes Nilsson was last updated on October 19, 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.