Dr William Spencer Grigg, DO - Medicare Internal Medicine in Rochester, NY

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Dr William Spencer Grigg, DO is a medicare enrolled "Internal Medicine" physician in Rochester, New York. His current practice location is 601 Elmwood Avenue, Box 679, Rochester, New York. You can reach out to his office (for appointments etc.) via phone at (858) 275-4290.

Dr William Spencer Grigg is licensed to practice in Colorado (license number DR.0062850) and he also participates in the medicare program. He does not accept medicare assignments directly but he may accept medicare through third-party (refer to Reassignment section below) and may also prescribe medicare part D drugs. His NPI Number is 1578050266.

Contact Information

Dr William Spencer Grigg, DO
601 Elmwood Avenue, Box 679,
Rochester, NY 14642
(858) 275-4290
(585) 473-1573

Map and Direction




Physician's Profile

Full NameDr William Spencer Grigg
GenderMale
SpecialityInternal Medicine
Location601 Elmwood Avenue, Rochester, New York
Accepts Medicare AssignmentsMedicare enrolled and may accept medicare through third-party reassignment. May prescribe medicare part D drugs.
  NPI Data:
  • NPI Number: 1578050266
  • Provider Enumeration Date: 04/18/2018
  • Last Update Date: 07/22/2024
  Medicare PECOS Information:
  • PECOS PAC ID: 9234476300
  • Enrollment ID: I20220204000744

Medical Identifiers

Medical identifiers for Dr William Spencer Grigg such as npi, medicare ID, medicare PIN, medicaid, etc.
IdentifierTypeStateIssuer
1578050266NPI-NPPES

Medical Taxonomies and Licenses

TaxonomyTypeLicense (State)Status
207R00000XInternal Medicine TL.0007279 (Colorado)Secondary
208M00000XHospitalist DR.0062850 (Colorado)Secondary
390200000XStudent In An Organized Health Care Education/training Program TL.0007279 (Colorado)Secondary
207R00000XInternal Medicine DR.0062850 (Colorado)Primary

Medicare Reassignments

Some practitioners may not bill the customers directly but medicare billing happens through clinics / group practice / hospitals where the provider works. Medicare reassignment of benefits is a mechanism by which practitioners allow third parties to bill and receive payment for medicare services performed by them. Dr William Spencer Grigg allows following entities to bill medicare on his behalf.
Entity NameInpatient Services, Pc
Entity TypePart B Supplier - Clinic/group Practice
Entity IdentifiersNPI Number: 1710999768
PECOS PAC ID: 5496651267
Enrollment ID: O20031211000419
Entity NameCatholic Health Initiatives Colorado
Entity TypePart B Supplier - Clinic/group Practice
Entity IdentifiersNPI Number: 1356783351
PECOS PAC ID: 8022927342
Enrollment ID: O20031215000462
Entity NamePortercare Adventist Health System
Entity TypePart B Supplier - Clinic/group Practice
Entity IdentifiersNPI Number: 1760761928
PECOS PAC ID: 0941110886
Enrollment ID: O20090115000327
Entity NamePoudre Valley Medical Group Llc
Entity TypePart B Supplier - Clinic/group Practice
Entity IdentifiersNPI Number: 1225356868
PECOS PAC ID: 9638208549
Enrollment ID: O20100602000122
Entity NameBanner Hospital Based Physicians Colorado Llc
Entity TypePart B Supplier - Clinic/group Practice
Entity IdentifiersNPI Number: 1154679637
PECOS PAC ID: 6800031386
Enrollment ID: O20130404000393
Entity NameColorado Hospitalist Services, Pllc
Entity TypePart B Supplier - Clinic/group Practice
Entity IdentifiersNPI Number: 1265806178
PECOS PAC ID: 4486957578
Enrollment ID: O20160123000040
Entity NameSignify Health Medical Associates Pllc
Entity TypePart B Supplier - Clinic/group Practice
Entity IdentifiersNPI Number: 1750845863
PECOS PAC ID: 2163764424
Enrollment ID: O20190517001824

Medicare Part D Prescriber Enrollment

Any physician or other eligible professional who prescribes Part D drugs must either enroll in the Medicare program or opt out in order to prescribe drugs to their patients with Part D prescription drug benefit plans. Dr William Spencer Grigg is enrolled with medicare and thus, if eligible, can prescribe medicare part D drugs to patients with medicare part D benefits.

Mailing Address and Practice Location

Mailing AddressPractice Location Address
Dr William Spencer Grigg, DO
601 Elmwood Avenue, Box 679,
Rochester, NY 14642

Ph: (858) 275-4290		Dr William Spencer Grigg, DO
601 Elmwood Avenue, Box 679,
Rochester, NY 14642

Ph: (858) 275-4290

Reviews and Comments


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Medicare Program: Medicare is a federal government program which provides health insurance to people who are 65 or older. This program also covers certain younger people with disabilities (who receive Social Security Disability Insurance - SSDI), and people with End-Stage Renal Disease (permanent kidney failure requiring dialysis or a transplant, sometimes called ESRD.

Medicare Assignment: Assignment means that your doctor, provider, or supplier agrees (or is required by law) to accept the Medicare-approved amount as full payment for covered services. Most doctors, providers, and suppliers accept assignment, but you should always check to make sure. Participating providers have signed an agreement to accept assignment for all Medicare-covered services.

NPI Number: The National Provider Identifier (NPI) is a unique identification number for covered health care providers. The NPI must be used in lieu of legacy provider identifiers in the HIPAA standards transactions. Covered health care providers and all health plans and health care clearinghouses must use the NPIs in the administrative and financial transactions adopted under HIPAA (Health Insurance Portability and Accountability Act).

Our Data: Information on www.medicarelist.com is built using data sources published by Centers for Medicare & Medicaid Services (CMS) under Freedom of Information Act (FOIA). The information disclosed on the NPI Registry are FOIA-disclosable and are required to be disclosed under the FOIA and the eFOIA amendments to the FOIA. There is no way to 'opt out' or 'suppress' the NPPES record data for health care providers with active NPIs.