Medical Bills After an Accident: Who Pays and How It Works

By Maria Chen, JD | 14 Years in Personal Injury Law

Here is the question I hear more than any other from new clients: “The accident was not my fault. Why am I getting all these medical bills? Shouldn’t the other driver’s insurance be paying for this?”

It is a completely reasonable question. And the answer is one that frustrates almost everyone who hears it for the first time.

The at-fault driver’s insurance does not pay your medical bills in real time. They do not call the hospital and hand over a credit card. They do not set up a payment plan with your physical therapist. They do not cover your prescriptions at the pharmacy.

Instead, the at-fault party’s insurance typically pays one lump sum at the end of the claims process, after you have settled or won a judgment. That process can take months or even years. In the meantime, those bills need to be paid by someone.

This guide explains exactly how medical bills work after an accident: who pays what, when, and how it all gets sorted out at the end. If you have not already reviewed it, start with our complete guide on The First 72 Hours After a Personal Injury, which covers the immediate steps to protect both your health and your legal rights.

The Confusing Reality: Nobody Pays Your Bills Right Away

Let’s walk through a typical scenario. You are stopped at a red light. Another driver rear-ends you going 35 mph. The ambulance takes you to the emergency room. You get X-rays, a CT scan, and treatment for neck and back pain. The ER bill is $12,000.

You would reasonably expect the other driver’s insurance to cover this. After all, the accident was entirely their fault. But here is what actually happens:

The hospital sends the bill to you (or your health insurance).
The other driver’s insurance company opens a claim and begins their “investigation.”
Weeks or months pass while liability is assessed and damages are calculated.
Eventually, a settlement is reached or a lawsuit produces a judgment.
The at-fault driver’s insurance pays a lump sum that is supposed to cover medical bills, lost wages, pain and suffering, and other damages.

So during that entire waiting period, those bills are sitting somewhere. Understanding your options for handling them is critical.

Option 1: Using Your Own Health Insurance

This is the most common and often the best first step. If you have health insurance through your employer, the ACA marketplace, Medicare, or Medicaid, you can and should use it to pay for accident-related medical treatment.

Why this is smart:

Health insurance negotiated rates are significantly lower than “list price” billing. A hospital might bill $12,000 for an ER visit, but your health insurance’s negotiated rate might reduce that to $4,200. This matters because the lower the total medical bills, the more of your settlement you keep in your pocket (after subrogation, which we will discuss below).
It ensures you get treatment now. Waiting for the insurance claim to settle before getting treatment is a terrible strategy. Gaps in medical care hurt your case and, more importantly, hurt your health.
It protects you from collections. Unpaid medical bills go to collections, which damages your credit score. Using your health insurance prevents this.

The catch: subrogation.

When your health insurance pays for accident-related treatment, they acquire a right of subrogation. This means they have a legal right to be reimbursed from your eventual settlement. If your health insurance paid $4,200 for your ER visit and you later receive a settlement from the at-fault driver’s insurance, your health insurer will want that $4,200 back.

This is not optional. Subrogation rights are written into your insurance policy and, in the case of employer-sponsored plans governed by ERISA (the Employee Retirement Income Security Act of 1974), are enforceable under federal law.

However, subrogation amounts are often negotiable. An experienced attorney can frequently negotiate subrogation liens down by 25% to 50%, especially if the full settlement does not fully compensate you for all your damages. This negotiation is one of the less visible but most valuable things a personal injury attorney does for clients.

Option 2: MedPay (Medical Payments Coverage)

MedPay is an optional coverage on your auto insurance policy that pays for medical expenses resulting from a car accident, regardless of who was at fault. Not all drivers carry it, but if you do, it can be extremely valuable.

Key facts about MedPay:

Coverage limits typically range from $1,000 to $25,000, with $5,000 being the most common.
It pays regardless of fault. Whether you caused the accident or someone else did, MedPay covers your medical bills up to the policy limit.
It covers a range of expenses: hospital bills, doctor visits, X-rays, MRIs, surgery, ambulance rides, dental treatment related to the accident, and even funeral expenses in some states.
It usually does not have subrogation rights in most states. This means the money MedPay pays out does not need to be repaid from your settlement. However, this varies by state, so check your policy.
Filing a MedPay claim does not increase your premiums in most states, because it is a no-fault coverage.

How to use it: Contact your own auto insurance company and ask to file a MedPay claim. Provide them with your medical bills and records related to the accident. They should pay covered expenses directly.

Option 3: PIP (Personal Injury Protection)

PIP is similar to MedPay but broader in scope. It is required in no-fault states (currently 12 states plus Puerto Rico) and optional in others.

What PIP covers that MedPay does not:

Lost wages (typically 80% of your income, up to the policy limit)
Replacement services (costs for household tasks you cannot perform due to injury, like childcare or housekeeping)
Funeral expenses

PIP coverage limits vary significantly by state:

Florida: minimum $10,000
Michigan: unlimited (prior to 2019 reform, now offers tiered options from $50,000 to unlimited)
New York: minimum $50,000
New Jersey: minimum $15,000

Important PIP deadlines: Most states require you to seek medical treatment within 14 days of the accident to qualify for PIP benefits. In Florida, this 14-day window is strictly enforced. Miss it, and you lose your PIP coverage entirely.

Option 4: Letters of Protection (LOPs)

If you do not have health insurance, MedPay, or PIP, or if your coverage has been exhausted, a Letter of Protection (also called a “letter of guarantee”) may allow you to receive treatment now and pay later.

How it works:

Your attorney sends a letter to the medical provider stating that you have a personal injury claim pending.
The letter guarantees that the provider will be paid out of the eventual settlement or judgment.
The medical provider agrees to treat you now and wait for payment.

The advantages:

You get treatment even if you cannot afford it right now.
It keeps your claim moving forward with documented medical treatment.
It shows the insurance company that your injuries are serious enough to require ongoing care.

The disadvantages:

Not all providers accept LOPs. Hospitals, in particular, are less likely to accept them. Chiropractors, physical therapists, and pain management specialists are more likely to work on an LOP basis.
Treatment under an LOP is billed at the provider’s full retail rate, which is significantly higher than health insurance negotiated rates. This means more money coming out of your settlement.
If your case does not result in a settlement or judgment, you are still personally responsible for the bills.

A practical note: In my experience, LOPs work best when combined with health insurance. Use your health insurance for the big-ticket items (ER visits, MRIs, surgery) and LOPs for providers that do not accept your insurance or for treatment that has specific injury-related benefits (like specialized physical therapy).

Understanding Medical Liens

A medical lien is a legal claim against your settlement by a medical provider or insurer who paid for your treatment. Liens are the mechanism by which these parties ensure they get reimbursed.

Types of medical liens

Health insurance subrogation liens. As discussed above, your health insurer can assert a lien against your settlement for the amount they paid in accident-related treatment.

Hospital liens. In many states, hospitals can file a statutory lien against your personal injury claim for the cost of emergency treatment. These liens are governed by state law, and the rules vary significantly:

Some states cap hospital liens at a percentage of the settlement.
Some require the hospital to file the lien within a specific timeframe (often 30 to 180 days after treatment).
Some allow hospitals to lien against only the liability portion of your settlement, not the entire amount.

Medicare and Medicaid liens. If Medicare or Medicaid paid for your accident-related treatment, the federal government has a right to be reimbursed. These liens are governed by the Medicare Secondary Payer Act and are taken very seriously. Failing to properly resolve a Medicare lien can result in:

The settlement being held up indefinitely.
Personal liability for the attorney and the claimant.
Interest and penalties.

Medicare liens require special handling. The process involves notifying the Benefits Coordination & Recovery Center (BCRC), obtaining a conditional payment letter, and negotiating the final lien amount. This process can add 2 to 6 months to the resolution of your claim.

Medicaid liens operate similarly but are governed by state law rather than federal law, and the rules vary by state.

Provider liens (LOP liens). If you received treatment under a Letter of Protection, the provider has a lien against your settlement for the full amount of their bills.

How liens get resolved at settlement

When your case settles, your attorney does not simply hand you a check for the full settlement amount. Instead, the process typically works like this:

The settlement check goes into your attorney’s trust account.
Your attorney deducts their contingency fee (typically 33% to 40%).
Your attorney deducts case costs and expenses (filing fees, expert witness fees, medical record costs, etc.).
Your attorney negotiates and pays all outstanding liens.
The remaining balance goes to you.

Example settlement breakdown:

Item	Amount
Total settlement	$100,000
Attorney fee (33%)	-$33,000
Case costs	-$3,500
Health insurance subrogation lien (negotiated down from $18,000)	-$12,000
Hospital lien	-$8,500
Physical therapy (LOP)	-$6,000
Your net recovery	$37,000

This example illustrates why lien negotiation matters so much. Every dollar reduced from a lien is a dollar that goes directly into your pocket.

The “Made Whole” Doctrine

The made whole doctrine is a legal principle that can significantly benefit claimants dealing with subrogation liens. Here is how it works:

Under the made whole doctrine, your health insurance company cannot exercise its subrogation rights until you have been fully compensated (“made whole”) for all your damages. If your total damages are $200,000 but you only receive a $75,000 settlement (perhaps because the at-fault driver had limited insurance), the made whole doctrine may prevent your health insurer from taking any of that $75,000.

Important caveats:

The made whole doctrine is recognized in some states but not all.
ERISA-governed plans (most employer-sponsored health insurance) may be exempt from the made whole doctrine under federal law, following the Supreme Court’s decisions in cases like US Airways v. McCutchen.
Even in states that recognize the doctrine, insurance companies can sometimes override it with specific contract language.

This is an area where the specific laws of your state and the terms of your specific insurance policy matter enormously. Consult a qualified attorney in your state to understand how the made whole doctrine applies to your situation.

Negotiating Medical Bills Down

One of the most effective ways to increase your net recovery from a settlement is to negotiate your medical bills down. This happens at multiple levels.

Negotiating with health insurance (subrogation reduction)

As mentioned earlier, health insurance subrogation liens are often negotiable. Common arguments for reducing them include:

Common fund doctrine: The insurance company should share in the cost of obtaining the recovery (your attorney fees). If your attorney did all the work to get the settlement, the insurer should not get 100% reimbursement without contributing to those costs.
Made whole argument: If the settlement does not fully compensate you, the insurer should accept a reduced amount.
Comparative fault reduction: If your settlement was reduced due to comparative fault, the insurer’s lien should be proportionally reduced.

Typical subrogation reductions range from 25% to 50% of the original lien amount.

Negotiating with medical providers directly

If you received treatment under a Letter of Protection or have outstanding balances, your attorney can often negotiate directly with medical providers. Providers know that getting 70 cents on the dollar now is better than waiting years for payment through litigation or getting nothing if the case does not resolve favorably.

Typical provider bill reductions range from 15% to 40%, depending on the provider, the amount owed, and the total settlement.

Negotiating with Medicare and Medicaid

Medicare liens can be negotiated, but the process is formal and follows specific procedures. You (or your attorney) must submit a request for a compromise or waiver to the BCRC. Grounds for reduction include:

The settlement does not fully compensate you for all damages.
Attorney fees and costs should be proportionally allocated to the government’s recovery.
Financial hardship.

Medicare lien reductions of 25% to 40% are common when properly documented and argued.

Balance Billing: An Unexpected Problem

Balance billing occurs when a medical provider bills you for the difference between their full charge and what your insurance paid. For example, if a surgeon charges $15,000 for a procedure and your insurance pays $9,000, the surgeon might bill you $6,000 for the balance.

When this is most likely to happen:

Out-of-network providers. If you were taken to an emergency room that was out of your insurance network, or if an out-of-network specialist treated you at an in-network hospital, balance billing can occur.
Emergency room physicians. Even at in-network hospitals, the ER doctors, anesthesiologists, and radiologists may be independent contractors who are out of network.

Protection against balance billing:

The No Surprises Act, which took effect on January 1, 2022, provides significant federal protections against balance billing for emergency services and certain non-emergency services at in-network facilities. Under this law:

Emergency services must be billed at in-network rates, regardless of whether the provider is in your network.
You cannot be billed more than in-network cost-sharing amounts for emergency care.
Providers and insurers must resolve payment disputes through an independent dispute resolution process, not by billing you.

Some states have additional balance billing protections that may be even stronger than the federal law. Consult a qualified attorney in your state if you receive a balance bill for accident-related treatment.

Average Medical Costs by Injury Type

Understanding typical medical costs can help you evaluate whether your claim is being properly valued. Here are average costs for common accident injuries, based on national data:

Emergency room visit

Average cost: $2,200 to $3,300 (without advanced imaging)
With CT scan: add $1,500 to $3,500
With MRI: add $1,000 to $5,000
Ambulance transport: $1,200 to $2,500 (ground), $12,000 to $25,000 (air)

Soft tissue injuries (sprains, strains, whiplash)

Initial treatment: $2,000 to $5,000
Physical therapy (12 to 24 sessions): $3,000 to $8,000
Total typical cost: $5,000 to $15,000

Herniated or bulging disc

Diagnosis (MRI, specialist consultation): $2,500 to $6,000
Conservative treatment (physical therapy, injections): $5,000 to $15,000
Epidural steroid injections (series of 3): $4,500 to $9,000
Surgery (discectomy or fusion): $30,000 to $150,000
Total range: $12,000 to $180,000

Broken bones

Simple fracture (cast, follow-up): $2,500 to $7,500
Compound fracture (surgery, hardware): $15,000 to $75,000
Physical therapy for recovery: $3,000 to $10,000

Traumatic brain injury (TBI)

Mild concussion (ER, follow-up): $3,000 to $10,000
Moderate TBI (hospitalization, imaging, rehabilitation): $50,000 to $200,000
Severe TBI (ICU, surgery, long-term rehabilitation): $300,000 to $1,000,000+

Spinal cord injury

First-year costs for paraplegia: approximately $560,000
First-year costs for quadriplegia: approximately $1,100,000
Lifetime costs: $1.5 million to $5 million+

These numbers are averages and vary significantly by geographic region, provider, and individual circumstances. They are provided to give you a general framework for understanding the scale of medical costs involved in personal injury claims.

Why Gaps in Treatment Hurt Your Case

This is one of the most important things I tell every client: do not stop treating until your doctor says you are done. Gaps in medical treatment are one of the single biggest factors that reduce claim values.

Here is why:

The insurance company’s argument

If you go to the ER, see a doctor once the following week, and then do not seek treatment again for 6 weeks, the insurance company will argue:

“If the claimant’s injuries were really that severe, they would have continued treatment.”
“The gap in treatment proves the claimant recovered and then re-injured themselves in a separate incident.”
“The later treatment is unrelated to the accident.”

The reality

People stop treatment for many reasons that have nothing to do with recovery:

They cannot afford the copays or deductibles.
They cannot take time off work for appointments.
They are overwhelmed and simply forget to schedule follow-ups.
They feel somewhat better and assume the issue has resolved (when it has actually only temporarily improved).

What to do

Follow your doctor’s treatment plan exactly. If they prescribe physical therapy 3 times a week for 8 weeks, go 3 times a week for 8 weeks.
If you must miss appointments, reschedule immediately. A gap of more than 2 weeks between appointments starts to raise red flags.
Document the reason for any gap. If you missed appointments because of work obligations, childcare issues, or financial constraints, make sure your attorney knows. They can address this in negotiations.
If you cannot afford treatment, talk to your attorney about options. LOPs, MedPay, and other resources can bridge financial gaps.
Do not stop treatment because you “feel fine.” Feeling better is not the same as being fully recovered. Follow up with your doctor and let them make the determination.

How Bills Are Resolved at Settlement: A Step-by-Step Walkthrough

Let’s walk through a complete example to illustrate how all these pieces fit together.

The scenario

Sarah is rear-ended on the highway. She suffers a herniated disc at L4-L5 and a mild concussion.

Her medical treatment

Provider	Billed Amount	Paid By	Amount Paid
Ambulance	$2,800	Health insurance	$1,400
Emergency room	$8,500	Health insurance	$3,800
MRI (lumbar spine)	$3,200	Health insurance	$1,600
Orthopedic surgeon (consultations)	$2,400	Health insurance	$1,200
Physical therapy (36 sessions)	$7,200	Letter of Protection	$7,200
Epidural injections (3)	$6,900	Health insurance	$3,400
Neurologist (concussion follow-up)	$1,800	Health insurance	$900
Total billed	$32,800		$19,500

The settlement

Sarah’s case settles for $85,000.

The breakdown

Item	Amount
Total settlement	$85,000
Attorney fee (33%)	-$28,050
Case costs (medical records, filing fees)	-$1,800
Health insurance subrogation lien ($12,300, negotiated down 35%)	-$7,995
Physical therapy LOP (negotiated down 20%)	-$5,760
Sarah’s net recovery	$41,395

Without lien negotiation, Sarah would have received $33,950. The attorney’s negotiation of liens put an additional $7,445 in her pocket.

For more on understanding the value of your claim, see our guide on how much your personal injury case is worth. And for a detailed walkthrough of the claims process itself, read our guide on the personal injury claim process, step by step.

Special Rules: Medicare and Medicaid Liens

Medicare and Medicaid liens deserve special attention because they involve the federal and state governments, which means the rules are stricter and the consequences of noncompliance are more severe.

Medicare

If you are a Medicare beneficiary (age 65+, disabled, or with end-stage renal disease), and Medicare pays for your accident-related treatment, the federal government has an automatic right of reimbursement under the Medicare Secondary Payer Act (MSP).

Key rules:

You must notify Medicare that you have a personal injury claim. Your attorney typically does this by sending a letter to the Benefits Coordination & Recovery Center (BCRC).
Medicare will issue a conditional payment letter listing all the payments they believe are related to your accident.
You have the right to dispute items on the conditional payment letter that are unrelated to the accident.
The final Medicare lien must be resolved before the settlement can be distributed. If it is not, both you and your attorney can be held personally liable.
Medicare Set-Aside (MSA): In some cases, particularly those involving future medical treatment, you may need to establish a Medicare Set-Aside account, which sets aside a portion of the settlement to cover future accident-related medical costs that Medicare would otherwise pay. This is most common in workers’ compensation cases but can apply to personal injury cases as well.

Medicaid

Medicaid liens are governed by state law and vary significantly from state to state. However, the general principle is the same: if Medicaid paid for your accident-related treatment, the state Medicaid agency has a right to be reimbursed from your settlement.

Key differences from Medicare:

Medicaid liens are governed by state law, not federal law, so the rules, deadlines, and negotiation procedures vary.
Many states cap Medicaid liens at a fraction of the settlement amount.
The anti-lien provision of the federal Medicaid statute (42 U.S.C. 1396p) limits when and how states can assert liens.
The Supreme Court’s decision in Arkansas Dept. of Health and Human Services v. Ahlborn limits Medicaid liens to the portion of the settlement that represents medical expenses, not the entire settlement.

How Attorney Fees Interact with Medical Bills

Understanding how attorney fees work is important context for understanding your net recovery. For a complete breakdown, see our guide on how personal injury attorney fees work.

The basic structure:

Most personal injury attorneys work on a contingency fee basis: they take a percentage of the recovery and charge nothing if you do not recover.
Typical contingency fees are 33% if the case settles before a lawsuit is filed and 40% if the case goes into litigation.
Attorney fees are calculated on the gross settlement before liens and costs are deducted.

This means that in a $100,000 settlement with a 33% contingency fee, the attorney receives $33,000. The remaining $67,000 is then used to pay liens and costs, with the balance going to you.

Some attorneys calculate fees differently, and some states have rules about the order in which fees, costs, and liens are deducted. This is another reason why understanding your fee agreement before signing it is critical.

Action Steps: What to Do Right Now

If you have been in an accident and are dealing with medical bills, here are the concrete steps you should take:

Use your health insurance for all accident-related treatment. Call your insurer and make sure they are aware the treatment is related to an accident. This ensures proper claim handling from the start.
Check your auto insurance policy for MedPay or PIP coverage. If you have it, file a claim immediately. This money is available to you regardless of fault.
Keep every medical bill, explanation of benefits (EOB), and receipt. Create a physical or digital folder dedicated to your accident-related medical expenses.
Do not pay medical bills out of pocket if you can avoid it. Use insurance first. If providers are demanding payment, explain that you have a personal injury claim pending and ask them to bill your health insurance or accept a Letter of Protection.
Do not ignore medical bills. Even if you believe the at-fault party’s insurance will eventually pay, unpaid bills can go to collections and damage your credit. Make sure someone is paying them, whether it is your health insurance, MedPay, PIP, or a provider agreement.
Follow your treatment plan without gaps. This protects both your health and your claim.
Consult a qualified attorney in your state. Medical billing in personal injury cases is genuinely complicated. The interaction of health insurance, auto insurance, liens, subrogation, and settlement proceeds involves multiple areas of law. An experienced personal injury attorney handles these issues daily and can save you thousands of dollars through lien negotiation alone.

For the complete picture of what to do after an accident, from the first moments at the scene through the claims process, read The First 72 Hours After a Personal Injury.

Final Thoughts

Medical bills after an accident create stress on top of stress. You are already dealing with pain, disrupted routines, and the emotional aftermath of a traumatic event. Having a pile of bills arrive in the mail, sometimes totaling tens of thousands of dollars, can feel overwhelming.

But the system, while confusing, is navigable. Use your health insurance. Check for MedPay and PIP. Understand how liens work. Know that bills can be negotiated. And most importantly, do not try to figure this out alone when the stakes are this high.

The difference between handling medical bills correctly and handling them incorrectly can be tens of thousands of dollars in your net recovery. That is money that belongs in your pocket, not the insurance company’s.