2026 NPPES data Infectious Disease Physician NPI 1811056336 M.D.
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DAVID CHRISTIANSEN, M.D.

Infectious Disease Physician in MISSOULA, Montana. CMS National Plan and Provider Enumeration System profile including specialty classification, practice address, and Medicare prescribing data when reported.

Federal data — no proprietary rating. PlainDoctor publishes the actual CMS NPPES and Medicare records — NPI registration, specialty, practice location, and prescribing data — without a composite score or editorial opinion on top. Every field traces to a federal source.
Prescribing volume
951
Medicare Part D claims · 324 beneficiaries · Infectious Disease Physician avg: 816
Generic prescribing
57%
generic claims · 43% brand-name · higher generic rates reduce patient out-of-pocket costs
MIPS score
85.4319/100
▲ 2 pts above national avg 83.1 · [object Object]
What the federal data reveals: DAVID CHRISTIANSEN, M.D. is a Infectious Disease Physician ([object Object]) practicing in MISSOULA, Montana with a Medicare Part D prescribing footprint of 951 claims across 324 beneficiaries — 43% brand-name prescribing . Their CMS MIPS Final Score of 85.4319/100 (national average: 83.1) reflects performance across Quality, Cost, Interoperability, and Improvement Activities .

What stands out: DAVID CHRISTIANSEN, M.D. reported a CMS MIPS final score of 85.4319 out of 100, above the 83.1 national average, and filed 951 Medicare Part D claims in 2023. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

Board certification likely (heuristic — not verified)

DAVID CHRISTIANSEN, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + MIPS quality reporting + 1 hospital affiliation — signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).

DAVID CHRISTIANSEN, M.D. at a glance

High performer (top quartile)

NPI registry status

Active

Issued 12/08/2006

NPI 1811056336

Primary specialty

Infectious Disease Physician

Mid-sized

8,292 US NPIs in this specialty

Medicare Part D claims

951 17% vs specialty avg

2023 prescription claims

Specialty avg: 816

MIPS final score

85.4319/100 2.3319000000000045% pts

Above neutral band

vs 83.1 national avg

Specialty distribution in Montana

How Infectious Disease Physician compares to other specialties among Montana providers

Montana providers

Infectious Disease Physician share within Montana

1. Infectious Disease Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Infectious Disease Physician share within Montana

Medicare quality performance — MIPS

DAVID CHRISTIANSEN, M.D.'s 2023 MIPS final score plotted against the Infectious Disease Physician national average

High performer (top quartile)
MIPS Final Score
85.4319/100
vs 83.1 national avg · 2023 performance year

MIPS final score (Infectious Disease Physician) — 85.4319/100 vs national avg 83.1

0%100%National avg83%85.4%
MIPS final score (Infectious Disease Physician) — 85.4319/100 vs national avg 83.1

The Merit-based Incentive Payment System (MIPS) scores providers 0–100 across four performance categories: Quality, Cost, Promoting Interoperability, and Improvement Activities, weighted under 42 CFR §414.1380. Reporting is voluntary for many small practices, so absence of a MIPS score is not a quality signal.

Board certification through an ABMS or AOA member board signals voluntary post-licensure examination plus continuous Maintenance of Certification cycles. Verify any individual provider's status through certificationmatters.org (ABMS) or osteopathic.org (AOA).

DAVID CHRISTIANSEN, M.D. is a Infectious Disease Physician provider practicing in MISSOULA, Montana, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: M.D.. NPI: 1811056336. This profile includes practice location, specialty classification, and organizational affiliations from the CMS provider registry. Provider information is self-reported to CMS and updated monthly.

DAVID CHRISTIANSEN, M.D. appears in the CMS NPPES registry as a Infectious Disease Physician provider holding M.D. credentials at 500 W BROADWAY ST, MISSOULA, MT, 59802, with a listed phone of (406) 543-7271. NPI 1811056336 was issued on 12/08/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what CHRISTIANSEN most recently submitted to CMS rather than a vetted directory listing, which is why patients should always confirm the practice is still at this location before scheduling.

Medicare Part D records for calendar year 2023 show 951 prescription claims written by this provider, covering 324 Medicare beneficiaries and totaling roughly $353K in drug spend, split 43% brand-name and 57% generic by claim count, with an opioid prescribing rate of 2.1%. These figures capture only Medicare Part D — commercial insurance, Medicaid, and cash-pay prescriptions are not included, and any drug-beneficiary cell under 11 is suppressed by CMS for patient privacy. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 85.4319/100 for the 2023 performance year (Quality 85.9823, Cost 65.4573), compared with the national average of 83.1.

Infectious Disease Physician is a mid-sized specialty nationwide, with 8,292 enrolled providers across 54 states and an average of 816 Part D claims per prescriber, so the context for interpreting these metrics differs meaningfully from a primary-care baseline. Important: PlainDoctor is a directory of publicly available government data, not medical advice, a malpractice database, or a quality rating. Inclusion here does not imply a recommendation, and absence of complaints or sanctions on this page does not mean none exist — always verify credentials through the NPPES NPI Registry, your state medical board, and the ABMS or AOA before making healthcare decisions.

Practice Address

500 W BROADWAY ST
MISSOULA, MT 59802

Provider Details

NPI 1811056336
Specialty Infectious Disease Physician
Credentials M.D.
Gender Male
NPI Issued 12/08/2006

CMS Quality Score (MIPS)

Merit-based Incentive Payment System (MIPS) scores from CMS, 2023 performance year.

85.4319
Final Score
Avg: 83.1
85.9823
Quality
65.4573
Cost
100
Promoting Interoperability

Reporting: Group practice

Hospital and facility affiliations

Facilities where DAVID CHRISTIANSEN, M.D. bills Medicare from. Star ratings (1-5) are CMS Hospital Compare's "Hospital overall rating" — a composite of mortality, readmission, patient experience, safety, timely care, and efficient use of medical imaging measures. Source: CMS Care Compare.

PROVIDENCE HEALTH AND SERVICES MT
MISSOULA, MT

Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).

Brand vs generic prescribing mix · Above average

DAVID CHRISTIANSEN, M.D. — brand share 43.0%
Specialty average (est.)

43% brand-name claims vs 57% generic, on 951 2023 Medicare Part D claims.

The federal Medicare Part D Generic Dispensing Rate national benchmark sits near 90% generic / 10% brand for primary-care prescribers, per CMS Office of the Actuary 2024 estimates. Higher brand share is common in specialty prescribing where generic equivalents are not available.

Medicare Part D Prescribing Data

CMS Medicare Part D prescriber-level data for calendar year 2023.

951
Total Claims
$353K
Total Drug Cost
324
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
1,178
Total Day Supply
23,198
Brand vs Generic
43% brand / 57% generic
Brand Drug Cost
$310K
Generic Drug Cost
$43K
Opioid Claims
20 (2.1% rate)
Antibiotic Claims
438

Patient Demographics

Average Patient Age
70.9 years
Avg HCC Risk Score
1.33
Gender Split
49% female / 51% male
Age Distribution
<65: 32, 65-74: 189, 75-84: 90, 85+: 13

Top Prescribed Drugs (Medicare Part D)

Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.

Drug Claims
Doxycycline Hyclate
85
Amoxicillin
82
Cefuroxime
Cefuroxime Axetil
60
Typhim Vi
Typhoid Vi Polysacch Vaccine
55
Sulfamethoxazole-Trimethoprim
Sulfamethoxazole/Trimethoprim
49
Cefadroxil
43
Shingrix
Varicella-Zoster Ge/As01b/Pf
42
Havrix
Hepatitis A Virus Vaccine/Pf
41
Amoxicillin-Clavulanate Potass
Amoxicillin/Potassium Clav
32
Cephalexin
29

* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.

Infectious Disease Physician Overview

How DAVID CHRISTIANSEN, M.D. fits within the Infectious Disease Physician landscape nationally.

8,292
Infectious Disease Physician Providers in US
54
States with Infectious Disease Physician
816
Avg Claims per Provider

DAVID CHRISTIANSEN, M.D.'s 951 claims are above the specialty average of 816.

Nearby Infectious Disease Physician Providers in Montana

Other clinicians with the same primary specialty enrolled in Montana, drawn from the same CMS NPPES roster as CHRISTIANSEN.

Compare Infectious Disease Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is DAVID CHRISTIANSEN, M.D.'s specialty?
DAVID CHRISTIANSEN, M.D. specializes in Infectious Disease Physician and practices in MISSOULA, Montana. Credentials: M.D..
How much does DAVID CHRISTIANSEN, M.D. prescribe under Medicare Part D?
In 2023, DAVID CHRISTIANSEN, M.D. wrote 951 Medicare Part D claims totaling $353K in drug costs for 324 beneficiaries.
What is DAVID CHRISTIANSEN, M.D.'s Medicare quality score?
DAVID CHRISTIANSEN, M.D. has a CMS MIPS Final Score of 85.4319/100 (Quality: 85.9823, Cost: 65.4573). The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is DAVID CHRISTIANSEN, M.D. located?
DAVID CHRISTIANSEN, M.D. is located at 500 W BROADWAY ST, MISSOULA, MT, 59802. Phone: (406) 543-7271.
What is DAVID CHRISTIANSEN, M.D.'s NPI number?
DAVID CHRISTIANSEN, M.D.'s National Provider Identifier (NPI) is 1811056336, issued on 12/08/2006.
Does DAVID CHRISTIANSEN, M.D. prescribe more brand-name or generic drugs?
DAVID CHRISTIANSEN, M.D.'s prescribing is 43% brand-name and 57% generic drugs by claim count, with $310K in brand drug costs.
Does DAVID CHRISTIANSEN, M.D. prescribe opioids?
Yes, DAVID CHRISTIANSEN, M.D. had 20 opioid claims in 2023 with an opioid prescribing rate of 2.1%.
How many Infectious Disease Physician providers are there in the US?
There are 8,292 Infectious Disease Physician providers across 54 states in the US. The average Infectious Disease Physician provider writes 816 Medicare Part D claims per year.
What drugs does DAVID CHRISTIANSEN, M.D. prescribe most often?
Based on 2023 Medicare Part D data, DAVID CHRISTIANSEN, M.D.'s most frequently prescribed drugs include Doxycycline Hyclate, Amoxicillin, Cefuroxime. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does DAVID CHRISTIANSEN, M.D. accept Medicare?
DAVID CHRISTIANSEN, M.D. appears in CMS Medicare data with 951 Part D claims and 324 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify DAVID CHRISTIANSEN, M.D.'s credentials?
DAVID CHRISTIANSEN, M.D.'s NPI is 1811056336 with credentials M.D.. You can verify this through the NPPES NPI Registry, check state medical board records, and confirm board certification through the ABMS or AOA.

Data Sources

Provider Directory
CMS National Plan and Provider Enumeration System (NPPES), download.cms.gov/nppes, updated monthly. Contains NPI, specialty, credentials, and practice location.
Specialty Classification
NUCC Health Care Provider Taxonomy (nucc.org), the industry standard for classifying provider specialties in Medicare and Medicaid billing.
Prescribing Data
CMS Medicare Part D Prescriber Public Use File (2023). Includes claims, drug costs, beneficiaries, and opioid prescribing rates.
Quality Performance
CMS Merit-based Incentive Payment System (MIPS) — 2023 performance year.
Limitations
Provider data is self-reported to CMS. Prescribing data reflects Medicare Part D only and does not include commercial insurance, Medicaid, or cash prescriptions. Claims below 11 beneficiaries are suppressed by CMS for privacy.

See our complete data methodology for details on how we collect and process government data.

Data as of April 2026 (NPPES) / 2023 (Medicare Part D). Source: Centers for Medicare & Medicaid Services (CMS).

Disclaimer: Data from CMS NPPES and Medicare Part D. PlainDoctor does not rate or rank providers. Provider information is self-reported and may not be current. Always verify information directly with the provider. About · Methodology