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CMS Price Transparency Data Hospital file updated: 9/19/2026

Blood test, magnesium

Facility: Greenwich Hospital Association -

Billing Code: 83735 (CPT)

Pillar 1 · The BaseRate™ CompositeHow 1.00× Fair BaseRate Works: Raw price averages unfairly penalize hospitals in high-wage cities or trauma centers treating sicker patients. We adjust for local CMS hospital wage levels and patient complexity first. A 1.00× score means right at the fair price average, 0.85× means 15% cheaper than fair market, and 1.30× means 30% above fair market.High Markup · Shop Alternatives
$9Fair BaseRate (4.00× Market)
Position vs. 1.00× Fair Price+300% Above Fair Price 1.00× (center of the bar) is the U.S. fair price average after accounting for local hospital wages and patient complexity. Left of center (<1.00×) is below fair price; right of center (>1.00×) is above fair price.

This hospital's typical commercial price is $36 compared to the $9 fair price benchmark.

Pillar 2 · VeriRate™ Data TrustHow VeriRate™ (0–100) Works: Hospitals are legally required to publish machine-readable price files, but some bury fake $0.01 numbers or omit cash discounts. VeriRate audits each file across 5 checks (hover any badge below to see what it tests).86/100 · Verified
86/100Hover Any Check Below to See How Prices Were Audited
File Completeness90Provenance (File Completeness): Checks whether the hospital published a complete, up-to-date machine-readable price file with valid CPT and MS-DRG billing codes instead of leaving blanks.
Price Logic88Coherence (Price Logic): Checks whether the hospital’s numbers make basic sense — e.g., self-pay cash price is lower than gross list price, with no fake $0.01 or $999,999 placeholder numbers.
Peer Alignment86Concordance (Peer Alignment): Checks whether reported prices sit in a realistic range compared to Medicare and nearby hospitals rather than wild 100× unit errors.
Clean Billing83Regularity (Clean Billing): Checks whether rates are structured consistently across procedures without erratic statistical spikes or hidden unbundled facility fees.
Real Cash Discount84Cash Honesty (Real Cash Discount): Checks whether the hospital offers a genuine self-pay cash discount that beats or matches commercial insurance rates instead of billing full sticker price.
Pillar 3 · Clinical Quality & ER SpeedChecks whether higher hospital prices actually buy better clinical quality — combining CMS Star Ratings, hospital safety scores, and emergency room wait times.High-Markup · Check Safety
CMS Star Rating5/5 StarsOfficial CMS Overall Hospital Quality Star Rating (1 to 5 stars) summarizing mortality, safety of care, readmissions, and patient experience.
Safety Score96/100Composite patient safety score (0–100) derived from CMS hospital-acquired infection rates (CLABSI, CAUTI, MRSA, C. diff), surgical complications, and HCAHPS surveys.
Typical ER WaitNo ER DataMedian minutes patients spent in the emergency department before leaving from the visit, as reported to CMS Timely and Effective Care.

5-Star CMS clinical quality rating paired with 4.00× fair market pricing.

The BaseRate · fair price high confidence
A fair price for this
$9
about 1.3× the $7 Medicare rate · typically $7–$19
modeled estimate · not a bill or quote
Medicare pays $7 Fair price $9 Cash price $36 Hospital's list price $69

How we calculate the fair BaseRate →

What each insurance company pays

Which insurers have negotiated a price with this hospital for this procedure — and which haven’t.

4 of 6 major insurers have a published price at this hospital

UnitedHealthcareBlue Cross Blue ShieldAetnaCigna HumanaKaiser Permanente

Crossed out = this hospital hasn’t published a negotiated price for that insurer for this procedure. It doesn’t necessarily mean they aren’t accepted — ask your insurer.

Insurance company Price range vs. Medicare
UnitedHealthcaremajor $8 - $20 119%
Blue Cross Blue Shieldmajor $7 - $21 104%
Aetnamajor $7 - $11 104%
Cignamajor $25 373%
Harvard Pilgrim $22 328%
MagnaCare $45 672%
Oscar Health $23 343%
+ 9 smaller / regional plans $10 - $59
Government programs also on file: Medicare.
Excludes 2 rental-network / third-party entries (e.g. Multiplan, PHCS) — these are pricing networks, not insurers.

Self-Pay How to get the cash price

Insurance Before you use insurance

Estimate your out-of-pocket cost

A rough estimate of what you’d pay with insurance (deductible + coinsurance) versus paying the cash price yourself.

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Facility Profile & Credentials

  • Address: 5 Perryridge Rd, Greenwich, CT 06830
  • CMS Rating: 5 / 5 Stars
  • Ownership Type: Voluntary non-profit - Private
  • Hospital Type: Acute Care Hospitals

Other Procedures at Greenwich Hospital Association -

Compare: Blood test, magnesium at other CT hospitals

Insurance negotiated median for the same procedure, sorted lowest first.

Inline Bill X-Ray & 501(r) Calculator 501(c)(3) Nonprofit · Free Care ≤200% FPL · AGB Cap 36.3%

Audit a Bill or Quote at Greenwich Hospital Association - (Zero PHI Required)

CMS CCN: 070018
CPT 83735
Fair BaseRate™ $9
Medicare Rate $7
Self-Pay Cash $36
Insurer Median $10
Pre-filled with Greenwich Hospital Association -’s charged/list benchmark
Screened against 2026 HHS Federal Poverty Guidelines
2026 FPL: $15,650 + $5,500 per additional person
Step 1 · 501(r) Charity Care Check 501(r) AGB Cap: $25 (274% FPL)

Statutory 501(r) AGB Cap Limits Bill to $25

At 274% FPL (201%–400% FPL tier), 26 U.S.C. § 501(r)(5) caps FAP-eligible bills at Amounts Generally Billed (36.3% of gross = $25).

Step 2 · Cash vs. Insurance Arbitrage Save $33 Paying Cash

Self-Pay Cash Rate ($36) Beats Your Bill

Greenwich Hospital Association -'s published 45 CFR § 180 self-pay cash rate is $36 (vs. $10 commercial insurer median). Ask billing to reclassify the visit to prompt-pay self-pay if it beats your deductible.

Step 3 · Fair BaseRate Target +$60 Above Fair BaseRate

Negotiate Toward $9 Fair BaseRate ($7 Medicare)

Your bill ($69) is $60 above the denoised Fair BaseRate ($9) and 9.9× the $7 Medicare rate.

1-Click Factual Dispute Summary: Copy a citation-backed benchmark memo (with CMS CCN, CPT code, Medicare reference, Fair BaseRate, and 26 U.S.C. § 501(r) calculations) to paste into patient-portal messages or billing appeals.
CMS Care Compare Public Quality Record

Clinical Quality, Patient Experience & Infection Benchmarks

CMS Overall5/5 Stars (5/5)

Source: CMS Hospital Care Compare. Clinical quality metrics summarize historical facility-wide cohorts and are not medical advice for individual care decisions.

Care-Setting Arbitrage, Bilateral SVD Insurer Leverage & Regional Alternatives

How to Pay Less Nearby: Freestanding Centers, Insurer Leverage & Outpatient Savings

45 CFR § 180 Primary-Source Lineage & Federal Verification Verified CMS CCN 070018

Verify the Raw Data: Official Hospital MRF, CMS Medicare.gov & Federal Filings

MRF Portal Indexed (06-0646659-Greenwich_Hospital_Standard_Charges-1.ashx) Verify on CMS Medicare.gov (CCN 070018) ↗ CMS HCRIS Cost Reports ↗
Published MRF File06-0646659-Greenwich_Hospital_Standard_Charges-1.ashx
Publication / Vintage9/19/2026 · 120.29 MB
Validated Rate Rows742,896 (CMS v3.0.0)
File Integrity Digest9f208f38dac8549e0382…

Safe-Harbor Data Corrections: Parsed directly from public 45 CFR § 180 hospital filings, CMS Care Compare, and CMS HCRIS cost reports. Hospital compliance officers may submit updated MRF URLs or rate tables for verification.

Submit MRF Update Correction Policy