Martha Sierra Diaz, PA-C
- Medicare services, 2024
- 450
- Medicare patients, 2024
- 116
- Part D claims, 2024
- 813
- MIPS score, 2024
- 87
- Hospital affiliations
- 4
- Practice address
- 20 York Street, New Haven, CT 06510
- Practice phone
- Call (203) 688-5900
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Yale New Haven Psychiatric Hospital (York St)
Psychiatric Inpatient Facility · New Haven, Connecticut
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Martha Sierra Diaz is a physician assistant in New Haven, Connecticut
Martha Diaz practices at Yale New Haven Psychiatric Hospital (York St) in New Haven, Connecticut.
Martha Diaz's NPI, 1538481882, was assigned on February 26, 2010. Martha Diaz graduated from JS Weill Medical College, Cornell University in 1995. Martha Diaz holds Connecticut license 000762.
- NPI
- 1538481882NPI Registry (opens in a new tab)
- Medicare PAC ID
- 5395873657
- NPI enumeration date
- February 26, 2010
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Practice phone
- (203) 688-5900
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Female
- Estimated age
- 57
- Medical school graduation
- 1995
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Martha Sierra Diaz practices at Yale New Haven Psychiatric Hospital (York St) in New Haven, Connecticut
Martha Diaz's primary practice is Yale New Haven Psychiatric Hospital (York St), at 20 York Street, New Haven, CT 06510. The practice phone is (203) 688-5900.
- Yale New Haven Psychiatric Hospital (York St)20 York Street, New Haven, CT 06510Phone(203) 688-5900
Source: Dmand AI Affiliation Data
Martha Sierra Diaz is affiliated with 5 sites of care and 1 medical group
Martha Diaz's primary practice is Yale New Haven Psychiatric Hospital (York St) in New Haven, Connecticut. Martha Diaz is also affiliated with Yale New Haven Hospital. The medical group on file is Yale Health. Dmand AI also links Martha Diaz to 3 more hospitals, each named with a free account.
Sources: Dmand AI Affiliation Data; and Dmand AI Org Hierarchy Data
Dmand AI tracks the EHR system at Martha Sierra Diaz's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Martha Diaz practices, 5 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Yale New Haven Psychiatric Hospital (York St) | Available with a free account |
| +4 more affiliated sites | Available with a free account |
Source: Dmand AI Technology Install Data
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Martha Sierra Diaz is one of 1,682 physician assistants in Connecticut
Physician assistant is Martha Diaz's primary specialty in the NPI Registry, under taxonomy code 363A00000X. Martha Diaz is board certified in certified physician assistant by the National Commission on Certification of Physician Assistants (NCCPA). Dmand AI has Martha Diaz's licenses on file in 2 states: Connecticut and Michigan.
Specialties and state licenses
- Physician assistant, ConnecticutPrimary
- Michigan license
Clinical focus
Dmand AI lists joint arthropathy among the conditions Martha Diaz treats.
Physician assistants near Martha Diaz
Counts of physician assistants 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
Martha Sierra Diaz billed Medicare for 450 services in 2024
CMS data shows 450 Medicare services from Martha Diaz across 3 procedure codes in 2024, all of them office visits, for 116 Medicare patients. Medicare paid $14,432 for them. Every service was in a facility, such as a hospital, rather than an office.
Martha Diaz compared with the Connecticut median for physician assistants, 2024
- Martha Diaz
- Connecticut median
- Medicare services
- 450vs 28657% above
- Medicare patients
- 116vs 10016% above
- Part D claims
- 650vs 2932.2 times
Medians across 1,046 physician assistants in Connecticut with Dmand AI profiles that report each measure.
Martha Diaz'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
Martha Sierra Diaz treated 116 Medicare patients in 2024, average age 73
CMS counts 116 Medicare patients who saw Martha Diaz in 2024. The largest group is 65 to 74, with 66 patients. 75% of them have high blood pressure, and 75% have high cholesterol. 19% are also on Medicaid. Their average risk score is 2.54, where 1.00 is the Medicare average, so they are sicker than most Medicare patients.
Across all payers, Dmand AI patient panel data puts Martha Diaz's median patient age at 73, with 100% women.
Martha Diaz's Medicare patients by age, 2024
CMS leaves out age groups with fewer than 11 patients.
Chronic conditions among Martha Diaz's Medicare patients, 2024
- High blood pressure75%
- High cholesterol75%
- Cancer59%
- Arthritis45%
- Anxiety35%
- Mood disorders33%
- Depression28%
- Diabetes24%
Share of Medicare patients with each condition. A patient can have several.
Martha Diaz's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 73
Patient panel by sex, all payers
- Women100%
- Men0%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Martha Sierra Diaz wrote 813 Medicare Part D claims in 2024
In 2024, Martha Diaz wrote 813 Medicare Part D claims for 227 patients. 82% of them were for generic drugs. CMS names the drug for 650 of them, across 22 drugs with 11 or more claims each, at $1,574,995 in total drug cost.
Martha Diaz's Part D claims by kind of drug, 2024
- Generic668 claims82%
- Brand-name145 claims18%
Martha Diaz'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 Martha Diaz's Part D claims, 2024
- Opioids7%56 of 813 claims
- Antibiotics3%27 of 813 claims
Share of all Part D claims for each drug class CMS reports on. Classes with no claims are left out.
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
Martha Sierra Diaz scored 87 out of 100 in Medicare's MIPS program for 2024
CMS publishes a Merit-based Incentive Payment System (MIPS) score of 87 out of 100 for Martha Diaz for performance year 2024, reported as part of a group. Martha Diaz accepts Medicare assignment, so Medicare's approved amount is taken as full payment.
- Accepts Medicare assignment
- Yes
Martha Diaz's MIPS scores, performance year 2024
- 87of 100Final score
- 77.4of 100Quality
- 100of 100Promoting Interoperability
- 40of 100Improvement Activities
- 74of 100Cost
Each score is out of 100. The final score weighs the categories CMS scored for this clinician.
Sources: Doctors and Clinicians National Downloadable File (CMS); and Clinician Public Reporting: Overall MIPS Performance (CMS), 2024 data, released September 10, 2026
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Martha Sierra Diaz graduated from JS Weill Medical College, Cornell University
Martha Diaz graduated from JS Weill Medical College, Cornell University in 1995.
- Medical school
- Board certified in certified physician assistant
Source: Dmand AI Professional Profile Data
Sources for Martha Sierra Diaz'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)Clinician Public Reporting: Overall MIPS Performance (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 Martha Sierra Diaz
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What is Martha Sierra Diaz's NPI number?
Martha Sierra Diaz's NPI number is 1538481882. It was assigned on February 26, 2010, and it is active in the NPI Registry.
What does Martha Sierra Diaz specialize in?
Martha Sierra Diaz is a physician assistant in New Haven, Connecticut. The primary specialty in the NPI Registry is Physician Assistant (taxonomy code 363A00000X).
Where does Martha Sierra Diaz practice?
Martha Diaz practices at 20 York Street, New Haven, CT 06510. Martha Diaz's primary practice is Yale New Haven Psychiatric Hospital (York St) in New Haven, Connecticut. Dmand AI also links Martha Diaz to 3 hospitals.
What is Martha Sierra Diaz's office phone number?
The practice phone on file for Martha Diaz is (203) 688-5900.
What is Martha Sierra Diaz's medical license number?
Martha Diaz holds Connecticut license 000762, one of the licenses on file in 2 states.
Which states has Martha Sierra Diaz been licensed in?
Dmand AI has state licenses on file for Martha Diaz in Connecticut and Michigan.
Which hospitals is Martha Sierra Diaz affiliated with?
Martha Diaz is affiliated with Yale New Haven Hospital. Dmand AI links Martha Diaz to 3 more hospitals.
What medical group is Martha Sierra Diaz part of?
Martha Diaz is linked to Yale Health.
Does Martha Sierra Diaz accept Medicare?
Yes. CMS data shows Martha Diaz billed Medicare for 450 services in 2024, and Martha Diaz accepts Medicare assignment.
What is Martha Sierra Diaz's MIPS score?
Martha Diaz's MIPS final score for performance year 2024 is 87 out of 100, reported as part of a group.
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How many Medicare patients does Martha Sierra Diaz see?
CMS counts 116 Medicare patients who saw Martha Diaz in 2024, with an average age of 73.
Is Martha Sierra Diaz board certified?
Yes. Martha Diaz is board certified in certified physician assistant by the National Commission on Certification of Physician Assistants (NCCPA).
What services does Martha Sierra Diaz bill to Medicare?
In 2024, Martha Diaz's most billed Medicare services were office visit, established patient (99212), office visit, established patient (99213) and office visit, established patient (99214).
Where did Martha Sierra Diaz go to medical school?
Martha Diaz graduated from JS Weill Medical College, Cornell University in 1995.
What drugs does Martha Sierra Diaz prescribe most?
In 2024 Medicare Part D data, Martha Diaz's most prescribed drugs by claims were Ondansetron ODT, Prochlorperazine Maleate and Dexamethasone.
How long has Martha Sierra Diaz been practicing?
Martha Diaz graduated from medical school in 1995, 31 years ago.
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