Margarita Castro-ZarragaMD
Family Medicine
2027 Medicare Advantage
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Medicare Advantage plans for Middlesex and Worcester counties, MA.
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Directory results See what each insurance company reports
Not checked yet
We haven't asked Aetna Medicare, Blue Cross Blue Shield of Massachusetts, Commonwealth Care Alliance Massachusetts, Commonwealth Care Alliance, Inc., eternalHealth, Fallon Health, Humana, Mass General Brigham Health Plan, Molina Healthcare of Massachusetts, Tufts Health Plan and UnitedHealthcare's directories about Margarita yet. A Silverpath advisor can check for you now.
The 71 Medicare Advantage plans we show for Middlesex and Worcester counties, MA in 2027
- 47 not listed
- 24 not checked yet
Aetna Medicare
Not checked yet.
4 more Aetna Medicare plans haven't been checked yet.
Blue Cross Blue Shield of Massachusetts
Not listed on its 6 plans here. That isn't proof they're out of network.
Commonwealth Care Alliance Massachusetts
Not listed on its 1 plan here. That isn't proof they're out of network.
Commonwealth Care Alliance, Inc.
Not listed on its 1 plan here. That isn't proof they're out of network.
eternalHealth
Not checked yet.
Fallon Health
Not checked yet.
3 more Fallon Health plans haven't been checked yet.
Humana
Not checked yet.
Mass General Brigham Health Plan
Not listed on its 5 plans here. That isn't proof they're out of network.
Molina Healthcare of Massachusetts
Not listed on its 3 plans here. That isn't proof they're out of network.
Tufts Health Plan
Not checked yet.
6 more Tufts Health Plan plans haven't been checked yet.
UnitedHealthcare
Not checked yet.
3 more UnitedHealthcare plans haven't been checked yet.
Premiums are each plan's own monthly premium, as filed with Medicare. You keep paying your Medicare Part B premium.
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Original Medicare
Original Medicare status
Most Medicare Supplement (Medigap) policies have no provider network: they help pay Original Medicare's cost sharing where Medicare is accepted. Medicare SELECT policies can require network providers for full benefits. Ask the office whether they accept Medicare.
Medicare enrollment and assignment have not been verified here. Advantage directory results do not answer this question.
No opt-out record in this CMS file. CMS's file covers data through 2026-08-31. This does not establish Medicare enrollment, assignment, or whether the office accepts new Medicare patients.
CMS opt-out source · Data through 2026-08-31 · Reviewed Oct 23, 2026
Where they practice
2 practice locations
- NPI issued
- 2009
- Registry record updated
- Jan 3, 2024
Medicare's clinician details aren't available on this page yet.
Questions
Common questions
Where does Margarita Castro-Zarraga practice?
2 locations, including 161 Jackson St, Lowell, MA. All of them are listed on this page.
How do I confirm Margarita is in my plan's network?
Call the member services number on your plan card and give them the NPI 1578705679, or ask a Silverpath advisor to check for you. It's free.
For providers
Is this your practice?
Patients can use Silverpath to find practices and check plan networks in Middlesex and Worcester counties, MA. Tell us which plans you take, or want to take, and we'll keep this page accurate and talk with you about reaching more Medicare patients and carriers.