PR-2 is the Patient Responsibility adjustment for coinsurance. It tells you the primary payer approved the service, paid its share/percentage, and assigned a percentage of the allowed amount to the patient. Despite the common label, it is not a denial. It is the normal result of a plan that splits the cost of care between the insurer and the member.
What makes PR-2 tricky is the arithmetic behind it. The percentage applies to the allowed amount, not the billed charge, it usually starts only after the deductible, and it can stop partway through a claim once the patient reaches the out of pocket maximum. This guide walks through the calculation, five worked cases, the situations where the patient should not be billed at all, and the errors in this Patient Responsibility Code that cause the number to be wrong.
PR-2 means coinsurance, the patient’s percentage share of the allowed amount after any deductible. Check that the percentage and the allowed amount match the plan, look for secondary coverage, and bill the patient only for what remains.
What is PR-2 in Medical Billing
The code has two parts. PR is the claim adjustment group code for patient responsibility, and 2 is the Claim Adjustment Reason Code (CARC) defined by X12 as coinsurance. Coinsurance is a percentage of the cost of a covered service that the patient pays after the plan applies its rules, for example 20% of the Medicare approved amount, with Medicare paying the other 80%.
Three points keep billers from misreading it:
- Coinsurance is a percentage, which separates it from a copay, a fixed dollar amount covered under PR-3 copay code.
- The percentage applies to the allowed amount, meaning the payer’s contracted or approved price for the service. Billed charges are not the base.
- PR-2 is a statement of responsibility. It does not confirm the percentage is right, so the amount still needs verification.
Where the Percentage Comes From
The coinsurance rate is set by the member’s plan, not by the payer’s claims system or the provider’s contract. A single plan can carry several rates, such as 10% for office visits, 20% for imaging and surgery, and 40% for out of network care. The rate also changes between plans from the same insurer, which is why a figure remembered from another patient is not a reliable check.
What PR-2 Looks Like on a Remittance
On the 835 electronic remittance advice, a coinsurance adjustment appears in a CAS segment with PR as the group code, 2 as the reason code, and the dollar amount third:
CAS*PR*2*120.00~
Many payers also report the allowed amount for the service line in an AMT segment, which gives you the base for your own calculation. On a paper EOB, look for a coinsurance column or a line labeled with the percentage.
A Quick Test: Work Backward to the Percentage
You can check any PR-2 line without opening the plan documents first. Divide the PR-2 amount by the allowed amount minus any deductible applied on the same line. If the result is 20%, 30%, or another round number that matches the benefit, the math is probably right. If the result is an odd figure, the payer used a different base, a different rate, or a different allowed amount.
How Payers Calculate Coinsurance
Most plans follow the same general sequence, although the details vary by plan:
- Start with the allowed amount for the service.
- Subtract any deductible still owed, which is covered in PR-1 deductible adjustments.
- Apply the coinsurance rate to what remains.
- Stop when the patient reaches the out of pocket maximum, after which the plan pays covered in network services in full.
Coinsurance = (allowed amount – deductible applied) x coinsurance rate, capped by the out of pocket maximum remaining
Here is the formula in numbers. A service has an allowed amount of $1,000 and the patient owes $200 toward the deductible. The coinsurance base is $800. At a 20% rate, PR-2 is $160 and the plan pays $640. If someone applied the 20% rate to a $2,500 billed charge instead, the result would be $500, which is the most common way a wrong PR-2 amount is produced.
Why the Base Amount Is Not Always the Same
The amount used to calculate coinsurance depends on the payer and the type of claim. For in-network claims, the base is usually the contracted rate, also called the allowed amount. Out-of-network claims may use a payer-defined allowed amount, such as a percentage of a reference fee schedule, which can be significantly lower than the provider’s billed charge. For Original Medicare, coinsurance is calculated using the Medicare-approved amount.
Payment adjustments can also change the base amount. For example, multiple procedure payment reductions on the same date of service may lower the allowed amount before coinsurance is calculated. The patient’s coinsurance is then based on that reduced figure. However, some health plans cover certain services, such as eligible preventive care, without patient cost sharing. In these cases, PR-2 (Coinsurance Amount) should not appear when no coinsurance applies.
Five PR-2 Cases With the Math
Case 1: Outpatient Imaging After the Deductible Is Met
Billed charge $1,500, allowed amount $600, contractual write off (CO-45) $900.
Coinsurance 20% of $600 = $120, which is PR-2.
The plan pays $480. Check: $480 + $900 + $120 = $1,500.
Case 2: Coinsurance Stops at the Out of Pocket Maximum
Billed charge $9,000, allowed amount $5,000, write off $4,000. The deductible is already met.
Coinsurance at 20% would be $1,000, but the patient has only $300 left before the out of pocket maximum.
PR-2 is $300 and the plan pays $4,700. Check: $4,700 + $4,000 + $300 = $9,000.
A PR-2 of $1,000 on this claim would be an error, and the patient’s remaining maximum is the proof.
Case 3: In Network Versus Out of Network
| Item | In network | Out of network |
| Allowed amount (same service) | $400 | $400 |
| Coinsurance rate | 20% | 40% |
| PR-2 | $80 | $160 |
| Plan pays | $320 | $240 |
The example holds the allowed amount constant to isolate the rate. In practice, out of network claims often have a lower allowed amount, and the provider may face additional balance billing rules. Federal protections limit patient cost sharing for emergency services and some out of network care at in network facilities, so verify those claims before billing the patient.
Case 4: Medicare Part B With a Medigap Plan
Billed charge $400, Medicare approved amount $250, write off $150. The Part B deductible is met.
Medicare coinsurance at 20% of $250 = $50, which is PR-2. Medicare pays $200.
A Medigap Plan G covers the Part B coinsurance, so the secondary payer pays $50 and the patient owes $0.
Check: $200 + $150 + $50 = $400.
Case 5: Medicare Hospital Stay Coinsurance
For Original Medicare inpatient stays, PR-2 can reflect daily coinsurance after day 60 of a benefit period. For 2026, CMS set it at $434 per day for days 61 through 90 and $868 per lifetime reserve day. Five days in the 61 to 90 range would produce $2,170 in coinsurance before any supplemental coverage pays.
When the Patient Should Not Be Billed for PR-2
A PR-2 line does not always mean a patient statement. Hold the balance in these situations:
- A secondary payer exists. A Medigap policy, an employer plan, or another coverage source may owe part or all of the coinsurance, and the claim should go there first.
- The patient is a Qualified Medicare Beneficiary. Federal rules generally prohibit billing QMB patients for Medicare deductibles, coinsurance, and copays. The cost sharing is directed to the state Medicaid program as allowed by the state, and the provider accepts that result.
- The out of pocket maximum was already reached, which means the coinsurance should not exist.
- The service is not covered. A non covered service is not subject to coinsurance. It is reported under a different reason, such as PR-204 service not covered by plan, and follows its own billing rules.
- The claim does not balance, or the group code looks wrong for the reason given.
Why PR-2 Amounts Go Wrong
| Cause | How it shows up | What to do |
| Coinsurance calculated on billed charges | PR-2 far larger than expected | Recalculate on the allowed amount and request correction |
| Wrong network tier or wrong plan | Rate does not match the benefit | Confirm network status and plan, then request reprocessing |
| Out of pocket maximum not applied | Patient shows the maximum met but PR-2 continues | Send accumulator proof and request reprocessing |
| Cost sharing on a service that should have none | PR-2 on a preventive visit | Review coding and plan rules, then dispute if exempt |
| Allowed amount below the contract rate | Implied percentage looks right but dollars are low | Compare to the fee schedule and file an underpayment dispute |
| Patient billed after the secondary paid | Statement shows the full PR-2 amount | Post the secondary remit first and bill only the remainder |
When the payer is the source of the error, gather the patient’s other EOBs, the eligibility response, and your fee schedule before you contact the payer.
PR-2 Decision Guide
| If this is true | Do this |
| Percentage and allowed amount match the benefit, and there is no other coverage | Post as patient responsibility and send a statement |
| Secondary coverage exists | Bill the secondary first and carry over the primary PR-2 amount |
| The patient is a QMB | Do not bill the patient for Medicare cost sharing; follow the state Medicaid process |
| The percentage or base looks wrong | Recalculate, document, and request reprocessing |
| The out of pocket maximum looks met | Compare accumulators and request reprocessing |
| The service is non covered | Use the non covered reason code workflow, not coinsurance |
Handling Coinsurance Conversations With Patients
Most coinsurance calls come from the same few misunderstandings. Having a ready response saves time and prevents unnecessary disputes.
| Patient says | What likely happened | Helpful response |
| “My plan covers 80%, so why do I owe anything?” | The 80% applies to the approved amount, and the other 20% is coinsurance | Show the approved amount and the 20% calculation |
| “The bill is far lower than your charges.” | A contractual adjustment reduced the charge to the allowed amount | Point to the write off as a separate line on the statement |
| “I already paid my deductible.” | The deductible and coinsurance are separate steps | Explain that coinsurance begins after the deductible |
| “Last time it was 20%, now it is 40%.” | A different network tier or service category applies | Confirm the provider network status and the benefit for that service |
| “I have a second insurance.” | Secondary coverage may pay the coinsurance | Collect the policy details and bill the secondary first |
Estimating Coinsurance Before the Visit
PR-2 is the most predictable of the cost sharing adjustments, which makes it the easiest to estimate at the front desk. Services with high allowed amounts, such as imaging, surgery, and infusion, carry the largest coinsurance balances, so an estimate matters most there.
- Confirm eligibility and network status for the date of service.
- Find the allowed amount in your contract or fee schedule.
- Subtract the deductible remaining, then apply the coinsurance rate for that service category.
- Check the out of pocket maximum remaining and cap the estimate if needed.
- Share the estimate with the patient and collect the expected portion at the point of service.
Practices can streamline estimates, collections, and payment posting by using revenue cycle management services to improve patient collections. These services help teams coordinate each step of the revenue cycle. Smaller offices can also use medical billing support for secondary claim follow-up to track secondary claims, bill the correct payer, and collect outstanding coinsurance.
PR-2 Trends Worth Watching
- The gap between the front desk estimate and the actual PR-2 amount, by payer.
- The share of PR-2 balances where secondary coverage existed but was not billed.
- The number of PR-2 lines disputed or reprocessed each month.
- The days between the remittance date and the patient statement.
How Can PHCS Help You Manage PR-2 Coinsurance Adjustments?
At PHCS, we help medical practices manage PR-2 coinsurance adjustments accurately and prevent incorrect patient billing. Our team verifies insurance benefits, reviews coinsurance calculations against allowed amounts and out-of-pocket limits, identifies secondary payer responsibilities, and resolves payment discrepancies.
Struggling with incorrect coinsurance balances or recurring PR-2 errors? Contact Proactive Healthcare Services today to streamline your billing process and protect your practice revenue.
Frequently Asked Questions
Q1- Is PR-2 the same as a copay?
No. PR-2 is coinsurance, a percentage of the allowed amount. A copay is a fixed dollar amount and is reported under PR-3.
Q2- Is coinsurance calculated on billed charges?
No. It is calculated on the allowed amount, or the Medicare approved amount for Original Medicare.
Q3- Can coinsurance be higher than 20%?
Yes. Rates vary by plan, service category, and network status, and out of network rates are often 30% or 40%.
Q4- Does coinsurance count toward the out of pocket maximum?
Generally yes for covered in network services, though the plan documents control.
Q5- Why does PR-2 often appear with PR-1?
When a claim includes the end of the deductible, the payer reports the remaining deductible under PR-1 and applies coinsurance to the rest under PR-2.
Q6- What does PR-2 mean on a Medicare remittance?
Usually the 20% Part B coinsurance on the Medicare approved amount, or the daily inpatient coinsurance under Part A.
Q7- Can I bill the patient after the secondary pays?
Only for the balance left after the secondary remittance/EOB is posted.
Q8- Does a PR-2 line need an appeal?
Only if the percentage, the base amount, or the accumulator data is wrong.
Conclusion
PR-2 is a common adjustment in medical billing that indicates the patient’s coinsurance responsibility. However, errors in the allowed amount, coinsurance percentage, or out-of-pocket maximum can lead to incorrect patient balances, billing disputes, and delayed collections. Before transferring any balance to the patient, verify the coinsurance calculation, review the payer’s explanation of benefits (EOB), and check for secondary insurance or applicable program-based protections.
Accurate handling of PR-2 helps medical practices avoid overbilling, reduce claim-related errors, and maintain patient trust. When discrepancies arise, identify the cause and determine whether the claim requires correction, reprocessing, or an appeal. The goal is to collect the correct patient responsibility while protecting both practice revenue and patients from unnecessary charges.
