Providers
All 9 in CA
MAI-KHANH BUI-DUY, M.D.
NPI 1275858409, individual, Watsonville, CA, Internal Medicine
4
Evidence tier
structure or single-organization volume
- Hours beyond a day in 1 month, but with up to 644 patients a month, which points to a supervising clinician on the claims rather than one person's hours.
- Records needed.
score 50 of 100, rank 9420, $240K at stake
Hours billed per day
Medicaid billing converted into hours of hands-on care per day. The lower bound counts one unit per claim line and needs no price; the other two divide dollars by a unit price, the conservative one at 1.5 times the price. The clinician on the claim may be a supervisor under state rules, so billing organizations are counted too.
| month | what was found | hours per day, lower bound | hours per day, at price | hours per day, conservative | per working day | patients | billing organizations | codes | paid |
|---|---|---|---|---|---|---|---|---|---|
| Nov 2024 | More hours than a day holds at a conservative unit price | 9.2 | 38.4 | 25.6 | 36.5 | 583 | 2 | 99212 99213 99214 G0442 | $34K |
National provider registry
From the CMS NPPES Registry, refreshed daily.
| Name | MAI-KHANH BUI-DUY, M.D. |
| Type | Individual |
| Status | Active |
| NPI issued | March 31, 2010, last updated March 24, 2020 |
| Practice location | 45 NEILSON ST, Watsonville, CA 95076-2468, 831-728-0222 |
| Mailing address | 204 E BEACH ST, Watsonville, CA 95076-4809 |
| Specialties | Internal Medicine (207R00000X, primary, license A119506 CA) |
Procedures billed
The specific codes behind the dollars. Medicaid figures come from T-MSIS (2018 to 2024) and are compared with every other provider billing the same code; Medicare figures come from the 2024 physician and supplier file and compare this provider's submitted charge with what Medicare allowed, against the usual ratio for that code.
Medicaid, largest codes
| code | what it is | paid | share | per patient-month | typical | rank among providers | |
|---|---|---|---|---|---|---|---|
| T1015 | Medicaid service code | $5.7M | 84% | $260 | $182 (top 5% from $488) | 76th percentile | |
| 99213 | Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more | $547K | 8% | $25 | $44 (top 5% from $110) | 21st percentile | |
| 87428 | Detection test by immunoassay technique for severe acute respiratory syndrome coronavirus and influenza | $112K | 2% | $59 | $44 (top 5% from $75) | 69th percentile | |
| 99214 | Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more | $79K | 1% | $34 | $60 (top 5% from $133) | 19th percentile | |
| 99395 | Medicaid service code | $71K | 1% | $117 | $73 (top 5% from $138) | 89th percentile | |
| 99212 | Established patient office or other outpatient visit with straightforward medical decision making, if using time, 10 minutes or more | $53K | 1% | $18 | $28 (top 5% from $147) | 31st percentile | |
| G0442 | Annual alcohol misuse screening, 5 to 15 minutes | $52K | 1% | $21 | $3.03 (top 5% from $22) | 95th percentile | |
| G9920 | Medicaid service code | $37K | 1% | $34 | $0.17 (top 5% from $29) | 97th percentile |
Medicare Part B 2024, largest codes
| code | what it is | services | beneficiaries | paid | submitted per service | allowed per service | charge to allowed | usual for this code |
|---|---|---|---|---|---|---|---|---|
| G0442 | Annual alcohol misuse screening, 5 to 15 minutes | 106 | 106 | $2K | $50 | $21 | 2.4x | 2.2x (90th percentile 3.8x) |
| 87428 | Detection test by immunoassay technique for severe acute respiratory syndrome coronavirus and influenza | 26 | 24 | $2K | $64 | $62 | 1.0x | 1.9x (90th percentile 3.1x) |
| 83036 | Hemoglobin a1c level | 168 | 106 | $2K | $82 | $10 | 8.6x | 3.5x (90th percentile 6.9x) |
| 82947 | Blood glucose (sugar) level | 117 | 86 | $450 | $33 | $4 | 8.6x | 4.2x (90th percentile 8.6x) |
| 87880 | Detection test by immunoassay with direct visual observation for streptococcus, group a (strep) | 18 | 18 | $292 | $41 | $16 | 2.5x | 2.6x (90th percentile 4.1x) |
A submitted charge many times the allowed amount is common and lawful; it matters when it is far above what other providers submit for the same code.
In this area
9 providers in Santa Cruz County, CA carry an indicator in the public record, with $6.6M at stake between them. The most common is more hours than a day holds, on 5 of them, followed by part of a provider network on 4.
| tier | provider | at stake | why |
|---|---|---|---|
| 3 | SUTTER VISITING NURSE ASSOCIATION AND HOSPICE Santa Cruz, CA, ranked 809 | $199K |
|
| 3 | HOSPICE OF SANTA CRUZ COUNTY Scotts Valley, CA, ranked 1309 | $149K |
|
| 3 | DRIFTWOOD SANTA CRUZ OPERATING COMPANY, LP Santa Cruz, CA, ranked 3140 | $0 |
|
| 3 | LAZER HOLDINGS LLC Watsonville, CA, ranked 6675 | $0 |
|
| 4 | CASSY FRIEDRICH Santa Cruz, CA, ranked 8485 | $3.6M |
|
| 4 | VICTORIA CHEW Watsonville, CA, ranked 8832 | $1.5M |
|
| 4 | ANDREW GERENRAICH Santa Cruz, CA, ranked 9556 | $116K |
|
| 5 | CRISTINA GAMBOA Watsonville, CA, ranked 11140 | $685K |
Recent enforcement in CA
All releasesDepartment of Justice and HHS-OIG releases for this state, newest first. Each opens in a new tab.
DOJPleaded guiltyAug 27, 2026
Anaheim Woman Pleads Guilty to Submitting More Than $2.2 Million in Fraudulent Hospice Care Claims to Medicare
Galbraith submitted approximately $2,266,694 in claims to Medicare for hospice services for beneficiaries who did not have a terminal illness with a life expectancy of six months or less, and Medicare paid her company approximately $2,140,606.
DOJCivil settlementAug 26, 2026
DermTech Inc. to Pay Up to $5M to Resolve Allegations It Submitted False Claims to Medicare for Unreliable Skin Cancer Tests
DermTech Inc. submitted claims to Medicare for skin cancer tests conducted with an unvalidated positive control range and for tests lacking sufficient patient RNA, and did not retract results or adequately refund Medicare.
DOJCivil settlementAug 26, 2026
DermTech Inc. to Pay Up to $5M to Resolve Allegations It Submitted False Claims to Medicare for Unreliable Skin Cancer Tests
DermTech Inc. billed Medicare for skin cancer tests conducted using an unvalidated positive control range and for tests with insufficient patient RNA, and did not retract the results or adequately refund Medicare.
DOJCivil settlementAug 24, 2026
Medicare Advantage Provider Monogram Health Agrees to Pay $2.4 Million to Settle False Claims Act Lawsuit
Monogram knowingly submitted diagnosis codes in four HCCs that were not clinically accurate, not supported by medical record documentation, and/or did not require or affect patient care, inflating Medicare Advantage beneficiaries' risk scores and causing CMS to make higher capitated payments to Medicare Advantage Organizations.
DOJCivil settlementAug 24, 2026
Medicare Advantage Provider Monogram Health Agrees to Pay $2.4M to Settle False Claims Act Suit
Monogram Health knowingly submitted diagnosis codes within four HCCs that were not clinically accurate, not supported by medical record documentation, and/or did not require or affect patient care, inflating Medicare Advantage beneficiaries' risk scores and causing CMS to make higher capitated payments to MAOs.
Referral packet
The packet is a draft for a reviewer. It reads every public record behind this case, states what the records show with a citation for each finding, names the regulation each finding relates to, and lists the ordinary explanations to rule out first. It never asserts intent.