Dr. Rex Klein Baker II, MD
- Part D claims, 2024
- 282
- Industry payments
- $29
- Affiliated sites
- 1
- Medical groups
- 2
- State licenses
- 2
- Practice address
- 500 NE Multnomah St, Portland, OR 97232
- Practice phone
- Call (503) 813-2440
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Kaiser Foundation Health Plan of the Northwest
Portland, Oregon
Find Dr. Baker's professional email, personal email and mobile number
Dmand AI checks each channel through healthcare-specific waterfall enrichment. See what is on file with a free account, with practice phones, licenses and affiliations.
Dr. Rex Klein Baker II is a family medicine physician in Portland, Oregon
Dr. Baker practices at Kaiser Foundation Health Plan of the Northwest in Portland, Oregon.
Dr. Baker's NPI, 1891834891, was assigned on February 6, 2007. Dr. Baker graduated from University of New Mexico School of Medicine in 2004. Dr. Baker holds Colorado license DR.0067328.
- NPI
- 1891834891NPI Registry (opens in a new tab)
- Medicare PAC ID
- 1052483849
- NPI enumeration date
- February 6, 2007
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Practice phone
- (503) 813-2440
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 48
- Medical school graduation
- 2004
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Practice Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. Rex Klein Baker II practices at Kaiser Foundation Health Plan of the Northwest in Portland, Oregon
Dr. Baker's primary practice is Kaiser Foundation Health Plan of the Northwest, at 500 NE Multnomah St, Portland, OR 97232 in Multnomah County. The practice phone is (503) 813-2440.
- Kaiser Foundation Health Plan of the Northwest500 NE Multnomah St, Portland, OR 97232 · Multnomah CountyPhone(503) 813-2440
Sources: NPPES NPI Registry (CMS); and Dmand AI Practice Data
Dr. Rex Klein Baker II is affiliated with 2 sites of care and 2 medical groups
Dr. Baker's primary practice is Kaiser Foundation Health Plan of the Northwest in Portland, Oregon. The medical group on file is Kaiser Permanente Northwest. Dmand AI also links Dr. Baker to 1 more group practice or clinic and 1 medical group, each named with a free account.
Sources: NPPES NPI Registry (CMS); Dmand AI Practice Data; and Dmand AI Affiliation Data
Dmand AI tracks the EHR system at Dr. Rex Klein Baker II's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Baker practices. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Kaiser Foundation Health Plan of the Northwest | Available with a free account |
| +1 more site and 1 medical group | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Rex Klein Baker II is one of 2,398 family medicine physicians in Oregon
Family medicine is Dr. Baker's primary specialty in the NPI Registry, under taxonomy code 207Q00000X. Dmand AI has Dr. Baker's licenses on file in 2 states: Colorado and New Mexico.
Specialties and state licenses
- Family medicine, ColoradoPrimary
- New Mexico license
Family medicine physicians near Dr. Baker
Counts of family medicine physicians 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. Rex Klein Baker II's patients have a median age of 37
Across all payers, Dmand AI patient panel data puts Dr. Baker's median patient age at 37, with 61% women.
Dr. Baker's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 37
Patient panel by sex, all payers
- Women61%
- Men39%
Source: Dmand AI Patient Panel Data
Dr. Rex Klein Baker II wrote 282 Medicare Part D claims in 2024
In 2024, Dr. Baker wrote 282 Medicare Part D claims for 210 patients. 88% of them were for generic drugs. CMS names the drug for 126 of them, across 8 drugs with 11 or more claims each, at $1,099 in total drug cost. In 2023, CMS named 125 claims across 8 drugs.
Dr. Baker's Part D claims by kind of drug, 2024
- Generic249 claims88%
- Brand-name and other33 claims12%
Dr. Baker'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. Baker's Part D claims, 2024
- Opioids6%16 of 282 claims
- Antibiotics40%112 of 282 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: 1252024: 1261%
Drugs named by CMS: 8 in 2024, 8 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. Rex Klein Baker II takes part in Medicare
Dr. Baker 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. Rex Klein Baker II received $29 in industry payments in 2022
CMS Open Payments shows 2 general payments to Dr. Baker from 1 drug or device company in 2022. Food and beverage make up the largest share, 100% of the total. Neuronetics, Inc. paid the most, $29.
Companies that paid Dr. Baker the most, 2022 to 2022
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Dr. Rex Klein Baker II graduated from University of New Mexico School of Medicine
Dr. Baker graduated from University of New Mexico School of Medicine in 2004.
- Medical school
Source: Dmand AI Professional Profile Data
Sources for Dr. Rex Klein Baker II'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 | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Practice Data |
| Primary practice, affiliations and health system | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Practice DataDmand AI Affiliation Data |
| Medicare patients and the all-payer patient panel | Dmand AI Patient Panel Data |
| 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) |
| Training, board certification and memberships | Dmand AI Professional Profile Data |
| 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. Rex Klein Baker II
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. Rex Klein Baker II's NPI number?
Dr. Rex Klein Baker II's NPI number is 1891834891. It was assigned on February 6, 2007, and it is active in the NPI Registry.
What kind of doctor is Dr. Rex Klein Baker II?
Dr. Rex Klein Baker II is a family medicine physician in Portland, Oregon. The primary specialty in the NPI Registry is Family Medicine Physician (taxonomy code 207Q00000X).
Where does Dr. Rex Klein Baker II practice?
Dr. Baker practices at 500 NE Multnomah St, Portland, OR 97232. Dr. Baker's primary practice is Kaiser Foundation Health Plan of the Northwest in Portland, Oregon. Dmand AI also links Dr. Baker to 1 group practice or clinic and 1 medical group.
What is Dr. Rex Klein Baker II's office phone number?
The practice phone on file for Dr. Baker is (503) 813-2440.
What is Dr. Rex Klein Baker II's medical license number?
Dr. Baker holds Colorado license DR.0067328, one of the licenses on file in 2 states.
Which states has Dr. Rex Klein Baker II been licensed in?
Dmand AI has state licenses on file for Dr. Baker in Colorado and New Mexico.
What medical group is Dr. Rex Klein Baker II part of?
Dr. Baker is linked to Kaiser Permanente Northwest. Dmand AI links Dr. Baker to 1 more medical group.
Does Dr. Rex Klein Baker II accept Medicare?
Yes. CMS lists Dr. Baker as accepting Medicare assignment.
Where did Dr. Rex Klein Baker II go to medical school?
Dr. Baker graduated from University of New Mexico School of Medicine in 2004.
What drugs does Dr. Rex Klein Baker II prescribe most?
In 2024 Medicare Part D data, Dr. Baker's most prescribed drugs by claims were Doxycycline Monohydrate, Cefadroxil and Nitrofurantoin Mono-Macro.
Has Dr. Rex Klein Baker II received payments from drug or device companies?
CMS Open Payments shows $29 in general payments to Dr. Baker from 1 company from 2022 to 2022. The largest total came from Neuronetics, Inc.
How long has Dr. Rex Klein Baker II been practicing?
Dr. Baker graduated from medical school in 2004, 22 years ago.
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