Dr. Bartholomew David Sak, MD
- Medicare services, 2024
- 502
- Medicare patients, 2024
- 268
- Part D claims, 2024
- 547
- Hospital affiliations
- 4
- Industry payments
- $1,505
- Practice address
- 212 S Sullivan St, Fremont, MI 49412
- Practice phone
- Call (231) 924-3300
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Find Dr. Sak's professional email, personal email and mobile number
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Dr. Bartholomew David Sak is a hospitalist in Fremont, Michigan
Dr. Sak practices at Corewell Health Gerber Hospital in Fremont, Michigan, part of Corewell Health.
Dr. Sak's NPI, 1093755167, was assigned on June 7, 2006. Dr. Sak holds Michigan license 4301068868.
- NPI
- 1093755167NPI Registry (opens in a new tab)
- Medicare PAC ID
- 1658267877
- NPI enumeration date
- June 7, 2006
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Practice phone
- (231) 924-3300
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 59
- Medical school graduation
- 1993
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. Bartholomew David Sak practices at Corewell Health Gerber Hospital in Fremont, Michigan
Dr. Sak's primary practice is Corewell Health Gerber Hospital, at 212 S Sullivan St, Fremont, MI 49412 in Newaygo County. The practice phone is (231) 924-3300.
- Corewell Health Gerber Hospital212 S Sullivan St, Fremont, MI 49412 · Newaygo CountyPhone(231) 924-3300
Source: Dmand AI Affiliation Data
Dr. Bartholomew David Sak is affiliated with 4 sites of care and 7 medical groups
Dr. Sak's primary practice is Corewell Health Gerber Hospital in Fremont, Michigan, part of Corewell Health. Dr. Sak is also affiliated with Trinity Health Muskegon Hospital. The medical group on file is Trinity Health Medical Group. Dmand AI also links Dr. Sak to 2 more hospitals and 6 medical groups, each named with a free account.
Sources: Dmand AI Affiliation Data; and Dmand AI Org Hierarchy Data
Dmand AI tracks the EHR system at Dr. Bartholomew David Sak's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Sak practices, 4 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Corewell Health Gerber Hospital | Available with a free account |
| +3 more sites and 6 medical groups | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Bartholomew David Sak is one of 256 hospitalists in Michigan
Hospitalist is Dr. Sak's primary specialty in the NPI Registry, under taxonomy code 208M00000X. Dr. Sak is licensed in Michigan.
Specialties and state licenses
- Hospitalist, MichiganPrimary
Hospitalists near Dr. Sak
Counts of hospitalists with a Dmand AI profile, by place and practice. Each opens the list.
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Peer Benchmarks
Dr. Bartholomew David Sak billed Medicare for 502 services in 2024
CMS data shows 502 Medicare services from Dr. Sak across 5 procedure codes in 2024, for 268 Medicare patients. Medicare paid $37,946 for them. Every service was in a facility, such as a hospital, rather than an office.
Dr. Sak's Medicare services by type, 2023 to 2024
- 2023
- 2024
- Office and hospital visits
- 2023: 7952024: 50237%
Dr. Sak compared with the Michigan median for hospitalists, 2024
- Dr. Sak
- Michigan median
- Medicare services
- 502vs 37036% above
- Medicare patients
- 268vs 17058% above
- Part D claims
- 315vs 704.5 times
Medians across 243 hospitalists in Michigan with Dmand AI profiles that report each measure.
Dr. Sak's most billed Medicare procedure codes, 2024
CMS publishes codes billed for 11 or more Medicare patients. Each label is the code family; CPT descriptions are licensed by the AMA.
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Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Bartholomew David Sak treated 268 Medicare patients in 2024, average age 74
CMS counts 268 Medicare patients who saw Dr. Sak in 2024. The largest group is 75 to 84, with 82 patients. 75% of them have high blood pressure, and 75% have high cholesterol. 32% are also on Medicaid. Their average risk score is 2.56, where 1.00 is the Medicare average, so they are sicker than most Medicare patients.
Across all payers, Dmand AI patient panel data puts Dr. Sak's median patient age at 72, with 49% women.
Dr. Sak's Medicare patients by age, 2024
Dr. Sak's Medicare patients by sex, 2024
- Women11543%
- Men15357%
Chronic conditions among Dr. Sak's Medicare patients, 2024
- High blood pressure75%
- High cholesterol75%
- Heart failure60%
- Arthritis57%
- Chronic kidney disease57%
- Mood disorders50%
- Diabetes48%
- Depression47%
Share of Medicare patients with each condition. A patient can have several.
Dr. Sak's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 72
Patient panel by sex, all payers
- Women49%
- Men50%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. Bartholomew David Sak wrote 547 Medicare Part D claims in 2024
In 2024, Dr. Sak wrote 547 Medicare Part D claims for 112 patients. 87% of them were for generic drugs. CMS names the drug for 315 of them, across 11 drugs with 11 or more claims each, at $33,744 in total drug cost. In 2023, CMS named 236 claims across 13 drugs.
Dr. Sak's Part D claims by kind of drug, 2024
- Generic476 claims87%
- Brand-name and other71 claims13%
Dr. Sak's most prescribed drugs by claims, 2024
CMS names a drug when it has 11 or more claims. Share is of the claims for drugs CMS names.
Drug classes CMS tracks in Dr. Sak's Part D claims, 2024
- Opioids3%14 of 547 claims
- Antibiotics4%20 of 547 claims
Share of all Part D claims for each drug class CMS reports on. Classes with no claims are left out.
Part D claims for drugs CMS names, 2023 to 2024
- 2023
- 2024
- Claims for drugs CMS names
- 2023: 2362024: 31533%
Drugs named by CMS: 11 in 2024, 13 in 2023.
Sources: Medicare Part D Prescribers - by Provider and Drug (CMS), 2024 data, released May 6, 2026; and Medicare Part D Prescribers - by Provider (CMS), 2024 data
How Dr. Bartholomew David Sak takes part in Medicare
Dr. Sak accepts Medicare assignment, so Medicare's approved amount is taken as full payment.
- Accepts Medicare assignment
- Yes
Source: Doctors and Clinicians National Downloadable File (CMS)
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Dr. Bartholomew David Sak received $1,505 in industry payments from 2017 to 2025
CMS Open Payments shows 71 general payments to Dr. Sak from 18 drug and device companies from 2017 to 2025. Food and beverage make up the largest share, 100% of the total. Janssen Pharmaceuticals, Inc paid the most, $299.
General payments to Dr. Sak by program year, 2017 to 2025
Companies that paid Dr. Sak the most, 2017 to 2025
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Sources for Dr. Bartholomew David Sak's profile data
| Data on this page | Source |
|---|---|
| NPI, name, sex, specialty and licenses | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Professional Profile Data |
| Practice locations and phone | Dmand AI Affiliation Data |
| Primary practice, affiliations and health system | Dmand AI Affiliation DataDmand AI Org Hierarchy Data |
| Medicare services and procedure codes | Medicare Physician & Other Practitioners - by Provider and Service (CMS) (opens in a new tab) |
| State medians for the same specialty | Dmand AI Peer Benchmarks |
| Medicare patients and the all-payer patient panel | Dmand AI Patient Panel DataMedicare Physician & Other Practitioners - by Provider (CMS) (opens in a new tab) |
| Part D prescribing | Medicare Part D Prescribers - by Provider and Drug (CMS) (opens in a new tab)Medicare Part D Prescribers - by Provider (CMS) (opens in a new tab) |
| MIPS scores, telehealth, assignment and procedure percentiles | Doctors and Clinicians National Downloadable File (CMS) (opens in a new tab) |
| Industry payments | Open Payments (CMS) (opens in a new tab) |
| EHR at each practice site | Dmand AI Technology Install Data |
| Similar physicians | Dmand AI Affiliation Data |
Data last refreshed October 2026Report an inaccuracyRemove my information
FAQ
Frequently asked questions about Dr. Bartholomew David Sak
Spotted something out of date? Email hello@dmand.ai and we will check the record. Contact details live in the free trial.
What is Dr. Bartholomew David Sak's NPI number?
Dr. Bartholomew David Sak's NPI number is 1093755167. It was assigned on June 7, 2006, and it is active in the NPI Registry.
What kind of doctor is Dr. Bartholomew David Sak?
Dr. Bartholomew David Sak is a hospitalist in Fremont, Michigan. The primary specialty in the NPI Registry is Hospitalist Physician (taxonomy code 208M00000X).
Where does Dr. Bartholomew David Sak practice?
Dr. Sak practices at 212 S Sullivan St, Fremont, MI 49412. Dr. Sak's primary practice is Corewell Health Gerber Hospital in Fremont, Michigan, part of Corewell Health. Dmand AI also links Dr. Sak to 2 hospitals and 6 medical groups.
What is Dr. Bartholomew David Sak's office phone number?
The practice phone on file for Dr. Sak is (231) 924-3300.
What is Dr. Bartholomew David Sak's medical license number?
Dr. Sak holds Michigan license 4301068868.
Which hospitals is Dr. Bartholomew David Sak affiliated with?
Dr. Sak practices at Corewell Health Gerber Hospital in Fremont, Michigan. Dr. Sak is also affiliated with Trinity Health Muskegon Hospital. Dmand AI links Dr. Sak to 2 more hospitals.
What medical group is Dr. Bartholomew David Sak part of?
Dr. Sak is linked to Trinity Health Medical Group. Dmand AI links Dr. Sak to 6 more medical groups.
Does Dr. Bartholomew David Sak accept Medicare?
Yes. CMS data shows Dr. Sak billed Medicare for 502 services in 2024, and Dr. Sak accepts Medicare assignment.
How many Medicare patients does Dr. Bartholomew David Sak see?
CMS counts 268 Medicare patients who saw Dr. Sak in 2024, with an average age of 74.
What services does Dr. Bartholomew David Sak bill to Medicare?
In 2024, Dr. Sak's most billed Medicare services were hospital inpatient care (99232), hospital inpatient care (99233) and hospital inpatient care (99223).
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What drugs does Dr. Bartholomew David Sak prescribe most?
In 2024 Medicare Part D data, Dr. Sak's most prescribed drugs by claims were Metoprolol Succinate, Spironolactone and Losartan Potassium.
Has Dr. Bartholomew David Sak received payments from drug or device companies?
CMS Open Payments shows $1,505 in general payments to Dr. Sak from 18 companies from 2017 to 2025. The largest total came from Janssen Pharmaceuticals, Inc.
How long has Dr. Bartholomew David Sak been practicing?
Dr. Sak graduated from medical school in 1993, 33 years ago.
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