Knee MRI Bill Decoded: $4,200 Chargemaster Rate, $1,920 Allowed Amount, and How Presumptive Charity Care Can Cut What You Owe to $0

Your doctor says you need a knee MRI. The order goes out with a CPT code (73721) and a phone number for scheduling. Nobody mentions that the scan could be billed at $4,650 at one building and $400 at another across town, using the same kind of machine.

If that gap seems arbitrary, it's because the system never showed you the number that matters. You aren't missing something obvious. This post explains what's on a knee MRI bill, what you'd owe at different points in your deductible, and a charity care tool that is spreading to more states. It could mean you owe nothing.

A note on numbers: the dollar figures in the worked examples below are illustrative. They're modeled on the spread patterns we see when we compare Medicare's rates against commercial pricing, and your local prices will differ. That difference is the point of this post.

The four numbers on every knee MRI bill

Most people think a bill has one price. A hospital bill has four, and they don't mean the same thing.

1. Chargemaster rate. This is the hospital's internal list price for CPT 73721, an MRI of a lower-extremity joint without contrast. Almost nobody pays it, but it's where every discount starts. In our example it's $4,200 for the facility and $450 for the radiologist's read.
2. Allowed amount. This is what your insurer has agreed to treat as the price. In our example the hospital's facility fee is $1,800 and the radiologist's read is $120, so the total allowed amount is $1,920.
3. Your share. Your deductible, copay, or coinsurance is applied to the allowed amount, not to the chargemaster rate.
4. Balance bill. This is any amount above the allowed amount that a provider charges you. It's mostly prohibited for in-network care, and it shows up when providers are out of network or when billing mistakes happen.

The radiologist's read is often billed separately from the scan itself, with a "-26" modifier meaning the professional component. Many people open the bill expecting one line and find two or three. We unpack this in Hospital Bills $4,800 for an MRI, Insurance "Allows" $1,200, You Still Owe $960.

The price spread: same CPT code, four different totals

Here is how one CPT 73721 scan might price out at four places within about 15 miles of each other:

Where you book	Chargemaster (gross)	In-network allowed amount	Cash price
Hospital outpatient department	$4,650	$1,920	not offered
Hospital-owned imaging site	$2,900	$1,220	$1,000
Independent imaging center (in-network)	$1,100	$450	$400
Independent center, self-pay	n/a	n/a	$400

The most expensive option is 4.8 times the cheapest. Only one of those four numbers is the one you actually pay, and it depends on where you are in your year.

Hospital outpatient departments often add a "facility fee" that a freestanding imaging center doesn't charge. That's part of why one picture costs so much more in a hospital building. For how that plays out when a hospital acquires your doctor's practice, see our knee MRI price comparison.

We anchor comparisons like this to the Medicare benchmark in the cms-fee-schedule dataset (5,700 rows), then layer commercial and cash pricing on top. This is the kind of analysis Privenox runs for you, so you don't have to build the spreadsheet yourself.

What you owe at three deductible stages

The price spread is only half the story. The other half is your calendar. Take a plan with a $3,000 deductible, 20% coinsurance, and in-network care.

Your deductible status	Hospital outpatient ($1,920)	Hospital-owned site ($1,220)	Independent center ($450)
Stage 1: $0 met	$1,920	$1,220	$450
Stage 2: $2,500 met, $500 left	$784	$644	$450
Stage 3: deductible met	$384	$244	$90

The math behind each row:

• Stage 1. The whole allowed amount goes to your deductible, so you pay all of it: $1,920 versus $450. Choosing the independent center saves $1,470.
• Stage 2. The first $500 covers what's left of your deductible. At the hospital, 20% of the remaining $1,420 is $284, so you owe $500 + $284 = $784. At the independent center the whole $450 fits under the remaining $500, so you owe $450. The savings drop to $334.
• Stage 3. You pay only coinsurance. Hospital: 20% of $1,920 = $384. Independent center: 20% of $450 = $90. The savings are $294.

The same two buildings produce a $1,470 gap in January and a $294 gap in December. Neither number is on the scheduling screen.

Cash only wins when your deductible isn't met

Look at the $400 cash price against the table. At Stage 1, cash ($400) beats insurance ($450) by $50. But at Stage 3, using insurance costs $90, so paying $400 cash would cost you $310 more. Cash payments usually don't count toward your deductible either, unless you submit them to your plan, and not every plan accepts that. If you have a procedure coming later in the year, a $450 scan billed through insurance builds your deductible credit, while a $400 cash scan doesn't. For the full cash-versus-insurance breakdown, see How to Pay $400 for an MRI That Costs $3,500 at the Hospital.

If you'll hit your deductible anyway, the gap is smaller

Suppose you're having surgery later this year and know you'll meet your deductible. Then the MRI's location changes your year-end total only by the coinsurance on the price difference:

20% × ($1,920 − $450) = $294.

And if your total spending would reach your out-of-pocket maximum anyway, the MRI location may change your final total by $0. Your plan type and your calendar decide which of these three situations you're in. You can model your own numbers at Privenox, or compare other deductible levels in our post on MRI cost at a $1,500, $4,000, or $7,500 deductible.

Balance billing: when it applies and when it doesn't

Balance billing means a provider charges you the difference between their list price and what your insurer paid. Here is how it works for a knee MRI:

• In-network provider. The allowed amount is the price, and the provider generally can't bill you for more. You owe only your deductible, copay, or coinsurance.
• Out-of-network imaging center you chose. The provider can balance bill you. If their list price is $1,100 and your plan allows $300, you could be asked for the rest. The No Surprises Act doesn't protect you when you pick an out-of-network facility yourself.
• Out-of-network radiologist at an in-network hospital. The No Surprises Act generally protects you from surprise bills in this case, including for radiology, and you can't be asked to waive those protections. You should owe only your in-network cost-sharing. We cover disputes over these situations in Surprise Billing Disputes Hit a Record High in 2026.

Two more checks help. Confirm the radiologist group is in-network too, because it's billed separately. Then look at your EOB (Explanation of Benefits, the statement your insurer sends after a claim) to see whether the "patient responsibility" line matches what the provider billed you.

The tool that can zero out the hospital's share: presumptive charity care eligibility

Now the part that most people never hear about.

Nonprofit hospitals are required to have a financial assistance policy, commonly called charity care. In practice, getting it often means filling out long forms, gathering pay stubs, and hoping you applied in time. KFF Health News reported in Hospitals Have a Little-Known Tool To Prevent Medical Debt. Here's How It Works that some states now require hospitals to identify and automatically enroll patients who are eligible for charity care. This approach is called presumptive eligibility. The hospital uses information it already has, rather than making patients prove they qualify.

That changes the math on the hospital option. Here is an illustrative example. Say the hospital's policy covers 100% of costs up to 200% of the federal poverty level, with a sliding discount up to 400%. (For scale, 200% is about $64,300 for a family of four using the 2025 poverty guideline of $32,150. Check the current year's number.)

Household income	Discount	Your share of the $1,920 allowed amount (Stage 1)
180% of poverty level	100%	$0
300% of poverty level	60%	$768
450% of poverty level	none	$1,920

Even the middle row beats the independent-center option of $450 only if the discount is large enough. That's why it helps to know your eligibility before you pick a site, not after the bill arrives. Three practical points:

• It's not automatic everywhere. The KFF Health News piece describes states that require it. Elsewhere you still have to apply. Ask the hospital's billing department: "Do you screen patients for presumptive eligibility under your financial assistance policy?"
• You usually have time. Federal rules for nonprofit hospitals give patients at least 240 days after the first billing statement to apply. Don't wait that long, but a bill you've already received isn't a dead end.
• Charity care generally applies to the hospital's own bills. An independent imaging center typically has no equivalent program. Cheap and free can be different routes to a lower bill, and which one wins depends on your income.

For how state investigations have found hospitals setting eligibility thresholds inconsistently, see Hospital Charity Care Can Cut Your $3,200 MRI Bill to $0.

If you're on Medicare Advantage: check your 2027 plan before you need the scan

It's October 1, so Medicare's Annual Enrollment Period (October 15 to December 7) is two weeks away. Healthcare Dive reported in Insurers say their 2027 Medicare Advantage offerings preserve benefits. The data tells a different story that a Leerink Partners analysis of Medicare Plan Finder shows how the largest MA carriers' 2027 offerings compare with what insurers say publicly.

We can't tell you which specific benefit changed on your plan, and no article can. But imaging is one of the places where details differ. Before you re-enroll, open your 2027 plan documents and look for:

• The copay or coinsurance for diagnostic radiology (advanced imaging such as MRI is often listed separately from X-rays)
• Any prior authorization requirement for MRI
• Whether outpatient hospital and freestanding imaging center have different cost-sharing
• Your plan's maximum out-of-pocket limit

Original Medicare works differently, with a Part B deductible and 20% coinsurance and no yearly cap. That's covered in No Medicare Out-of-Pocket Maximum in 2026.

Two notes on location and privacy

Rural readers. A KFF-Associated Press survey, reported by KFF Health News in Rural MAHA Followers Say Trump Health Policies Haven't Reached Their Communities, found rural voters aren't seeing national health initiatives reach their local communities. Whatever your views on any policy, the price on your MRI is set by the facilities near you. In rural areas there may be only one or two imaging options, so a 40-minute drive to an independent center can be worth pricing out.

Using AI to read your bill. Healthcare Dive's Data privacy concerns could hold patients back from using AI points to a real worry. If you paste an EOB or itemized bill into any tool, remove your name, date of birth, member ID, and account numbers first. The CPT code, billed amount, and allowed amount are all you need to compare prices.

Your checklist before you schedule a knee MRI

1. Get the CPT code. Ask your doctor's office or check the order. For a knee MRI without contrast it's usually 73721, but confirm it.
2. Check your deductible status. Log into your insurer's portal. How much deductible is left decides which row of the table above is yours.
3. Price at least three places. Ask each for the in-network allowed amount for that CPT code, and ask whether the radiologist's read is billed separately.
4. Ask about cash pricing and financial assistance. The cash price is worth knowing at any facility. At a hospital, ask about presumptive eligibility too.
5. Confirm network status for both the facility and the radiologist. Get the name in writing if you can.
6. Save the quote. If the final bill is higher than what you were told, you'll have something to dispute with.

Our analysis draws on 16,357 data points across six sources: CMS fee schedules, ACA marketplace premiums, KFF employer benchmarks, BLS medical CPI, Census ACS health context, and national health expenditure defaults. It keeps pointing to the same lesson. What you owe depends on your plan, your deductible, and your zip code, and no national average can tell you that.

The bottom line

The same knee MRI can cost $450 or $1,920 in allowed charges, and what you personally owe can range from $0 to $1,920 depending on your deductible status and the hospital's charity care rules. That spread exists because prices aren't shown before you schedule. You can't be blamed for not knowing numbers the system doesn't make easy to find.

Before you book, compare prices for your procedure at facilities near you on Privenox. Enter your plan details and see what you'd owe at each one, so the first time you see your price isn't on the bill.

Data behind this post

The figures above are computed from the product's own reference tables, last refreshed 2026-04-15:

• 3,060 rows from aca-marketplace-premiums
• 1,080 rows from bls-medical-cpi
• 6,286 rows from census-acs-health-context
• 5,700 rows from cms-fee-schedule
• 31 rows from healthcare-defaults
• 200 rows from kff-insurance-benchmarks

Sources

• Hospitals Have a Little-Known Tool To Prevent Medical Debt. Here’s How It Works. — KFF Health News
• Rural MAHA Followers Say Trump Health Policies Haven’t Reached Their Communities — KFF Health News
• Insurers say their 2027 Medicare Advantage offerings preserve benefits. The data tells a different story — Healthcare Dive
• Mortgage Rates Today, Thursday, October 1: Rates Rise Sharply — NerdWallet Health Insurance
• Data privacy concerns could hold patients back from using AI — Healthcare Dive