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Compare the published Medicare service mix of Frederick Joseph Nachtwey, M.D. with clinicians in the same registry specialty: Internal Medicine · Pulmonary Disease · Sleep Medicine (CMS).

WALNUT CREEK, CA · Exact areaEdit location

2024 published service data · 13 eligible profiles compared. Similarity describes billing patterns, not quality, outcomes, or suitability for your care.

Jamal Julian Zaka, M. D.

Critical Care (Intensivists) · Pulmonary Disease (CMS) · Walnut Creek, CA

Shared published services
3 shared services · view billing descriptions
  • Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
  • Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)
90%Service-mix similarityView profile →

Ka Ling (Karin) Cheung, M.D.

Pulmonary Disease · Sleep Medicine (CMS) · Walnut Creek, CA

Shared published services
3 shared services · view billing descriptions
  • Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
  • Sleep study including heart rate, breathing, and sleep time (95800)
61%Service-mix similarityView profile →

Nick Sina Pakzad, M.D.

Critical Care (Intensivists) · Pulmonary Disease (CMS) · Walnut Creek, CA

Shared published services
3 shared services · view billing descriptions
  • Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)
  • New patient office or other outpatient visit with low level of medical decision making, if using time, 30 minutes or more (99203)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
50%Service-mix similarityView profile →

Mark Slootsky, M.D.

Critical Care (Intensivists) · Pulmonary Disease (CMS) · Walnut Creek, CA

Shared published services
3 shared services · view billing descriptions
  • Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
  • Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)
49%Service-mix similarityView profile →

Elvio Ardilles, MD

Pulmonary Disease (CMS) · Walnut Creek, CA

Shared published services
3 shared services · view billing descriptions
  • Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
  • Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)
49%Service-mix similarityView profile →

Manjari Nathan, M.D.

Critical Care (Intensivists) · Pulmonary Disease · Sleep Medicine (CMS) · Walnut Creek, CA

Shared published services
3 shared services · view billing descriptions
  • Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)
  • Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)
  • Test to examine how well the lungs exchange gases (94729)
46%Service-mix similarityView profile →

George Juan, M.D.

Critical Care (Intensivists) · Pulmonary Disease (CMS) · Walnut Creek, CA

Shared published services
3 shared services · view billing descriptions
  • Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
  • Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)
44%Service-mix similarityView profile →

Ming-Tyh Maa, M.D.

Critical Care (Intensivists) · Pulmonary Disease (CMS) · Walnut Creek, CA

Shared published services
3 shared services · view billing descriptions
  • Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
  • Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)
42%Service-mix similarityView profile →

Anne Maria Grzegorczyk, M.D.

Critical Care (Intensivists) · Pulmonary Disease (CMS) · Walnut Creek, CA

Shared published services
3 shared services · view billing descriptions
  • Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
  • Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)
39%Service-mix similarityView profile →

Vala Berjis, M.D.

Critical Care (Intensivists) · Pulmonary Disease (CMS) · Walnut Creek, CA

Shared published services
3 shared services · view billing descriptions
  • Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
  • Test to examine how well the lungs exchange gases (94729)
38%Service-mix similarityView profile →

Jigar Patel, M.D., M.P.H.

Critical Care (Intensivists) · Pulmonary Disease (CMS) · Walnut Creek, CA

Shared published services
3 shared services · view billing descriptions
  • Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)
  • Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)
  • Test to examine how well the lungs exchange gases (94729)
31%Service-mix similarityView profile →

Matthew Isaac Lyons

Critical Care (Intensivists) · Pulmonary Disease (CMS) · Walnut Creek, CA

Shared published services
3 shared services · view billing descriptions
  • Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
  • Test to examine how well the lungs exchange gases (94729)
30%Service-mix similarityView profile →
How this comparison works

We use the same calendar year of CMS Medicare Physician & Other Practitioners data for both providers. Published non-drug service counts are combined by HCPCS code across places of service. We apply log(1 + count), normalize the vectors, and compare them using cosine similarity.

Candidates share the reference provider’s current NPPES primary taxonomy and match the location you enter. We examine up to 500 candidates in NPI order, then show up to 12 with the highest positive similarity within that set. The score is not a percentile, medical recommendation, or prediction. Suppressed services are not estimated. Medicare fee-for-service data does not describe a provider’s entire practice.

Source: CMS Medicare Physician & Other Practitioners - by Provider and Service : 2024-12-01 · Published May 21, 2026.