Dr. William Norman Hamstra , DO

Medicare patients

49 people with Original Medicare in 2017

Different Original Medicare patients in 2017; counts below 11 are hidden; this does not show availability or quality.

It gives a sense of how many people with Medicare this clinician treated that year.

Source: CMS, Medicare Physician & Other Practitioners – by Provider, 2017.

Medicare-allowed amount

About $6,310 in 2017

The total amount Medicare approved for these services in 2017. 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.

Source: CMS, Medicare Physician & Other Practitioners – by Provider and Service, 2017.

Paid by Medicare

About $4,861 in 2017

The part of the Medicare-allowed amount that Medicare itself paid in 2017, after patients' deductibles and coinsurance.

The gap between the allowed amount and this number is roughly what patients and their other insurance paid.

Source: CMS, Medicare Physician & Other Practitioners – by Provider and Service, 2017.

30-day fills

44 standardized 30-day fills in 2024

CMS converts prescriptions to 30-day supplies so they can be compared. A 90-day prescription counts as about three 30-day fills.

Part D drug cost

$326 in 2024

The total cost of these prescriptions in 2024, paid by Medicare drug plans, patients and other payers together.

It shows the total spending on drugs this clinician prescribed, not what any one patient paid.

Source: CMS, Medicare Part D Prescribers – by Provider and Drug, 2024.

Industry payments (Open Payments)

Fewer than 11 payment records totaling $126.29 in 2022

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 2022.

Guide: How to read an Open Payments record

Years since graduation

40 years (graduated 1986)

CMS Doctors and Clinicians data list 1986 as the year this clinician finished professional school.

It tells you roughly how long ago the clinician finished school.

Source: CMS Doctors and Clinicians National Downloadable File, CMS release of October 2, 2026.

NPI first issued

2005

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.

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, CMS release of October 2, 2026; Medicare.gov, “Does your provider accept Medicare as full payment?”

Guide: What Medicare assignment means

No telehealth indicator

CMS shows this indicator only when recent Medicare claims include telehealth services. The clinician may still offer telehealth; ask the office.

Source: CMS, Telehealth Indicator on Medicare Care Compare (fact sheet, January 2023); CMS Doctors and Clinicians, CMS release of October 2, 2026.

Guide: How Medicare covers telehealth

Enrolled in Medicare (PECOS)

Dr. Hamstra 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.

Guide: What Medicare enrollment (PECOS) means

Can order Medicare-covered services

CMS lists Dr. Hamstra 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.

Source: CMS Medicare Fee-For-Service Public Provider Enrollment (PECOS); CMS Order and Referring file.

Guide: What ordering and referring status means