A Medicare write down is the difference between what a doctor charges and what Medicare actually pays

When you see a doctor who accepts Medicare, that doctor has agreed to accept Medicare's payment as full payment for the service. If the doctor's usual charge is $200 but Medicare decides the service is worth $120, the doctor writes off the remaining $80. That $80 is the write down — money the doctor cannot bill you for, even though it was part of their original fee.

The write down protects you from surprise bills. You pay only your share of what Medicare approves (your deductible, coinsurance, or copay), and the doctor absorbs the difference. This is one of the main reasons Medicare participation matters: doctors who do not accept Medicare can bill you for the full amount they charge, with no limit.

Key Takeaways

  • A write down is the amount a doctor forgoes when they accept Medicare's approved amount instead of their usual charge.
  • You are responsible only for your Medicare cost-sharing (deductible, coinsurance, or copay), not the write down.
  • Doctors who accept Medicare must write down the difference; doctors who do not accept Medicare can bill you the full amount they charge.
  • The write down amount varies by service, location, and what Medicare's fee schedule says that service is worth in your area.

How the write down amount is decided

Medicare sets an approved amount for each service based on a national fee schedule. This schedule is updated yearly and varies by geographic region — a knee X-ray in rural Montana may have a different approved amount than the same X-ray in New York City. The approved amount is what Medicare believes is reasonable payment for that service in that location.

When a doctor submits a claim to Medicare, the insurance compares the doctor's charge to the approved amount. If the doctor charged $200 and the approved amount is $120, Medicare pays its share of $120 (usually 80 percent after you meet your deductible), and you pay your share (usually 20 percent). The $80 difference is written off — the doctor cannot bill you for it.

Why doctors accept write downs

Doctors who accept Medicare agree to this arrangement because Medicare is a large, reliable source of patients and payment. Even though they write down the difference, they receive payment quickly and do not have to chase patients for unpaid bills. For many practices, the volume of Medicare patients makes the write down worthwhile.

Doctors who do not accept Medicare are called non-participating providers. They can charge whatever they want and bill you for the full amount. Some non-participating doctors will still see Medicare patients, but you become responsible for the entire bill, not just your coinsurance or copay. This is why checking whether a doctor participates in Medicare before your visit matters.

What you actually pay after a write down

The write down does not reduce what you owe Medicare — it reduces what the doctor can collect. Your responsibility is your cost-sharing amount: your deductible (if you have not met it), coinsurance (usually 20 percent of the approved amount), or a copay (a flat fee for certain services).

Using the earlier example: if the approved amount is $120, Medicare pays $96 (80 percent), and you pay $24 (20 percent coinsurance). The doctor's original $200 charge is irrelevant to you. You never see the $80 write down on your bill because it is not your responsibility.

Write downs on your Explanation of Benefits

When Medicare processes a claim, it sends you an Explanation of Benefits (EOB) that shows the doctor's charge, the approved amount, the write down, what Medicare paid, and what you owe. The write down line is sometimes labeled "contractual adjustment" or "non-covered amount."

Reading the EOB can be confusing because the numbers seem large — you see the original charge and wonder why you are not responsible for the difference. The write down line clarifies that you are not. If you disagree with the approved amount or think the write down is wrong, you can contact Medicare to request a review, though the approved amounts are set by federal formula and rarely change for individual claims.

Write downs versus denials

A write down is different from a denial. A write down means Medicare approved the service and paid its share; the doctor straightforward cannot bill you for the difference. A denial means Medicare decided the service was not covered or was not medically necessary, and neither Medicare nor you owes payment (though the doctor may still bill you if you signed a form saying you understood the service might not be covered).

If you receive an EOB showing a denial instead of a write down, the service itself is in question, not just the price. Denials are worth reviewing carefully, especially if you believe the service was necessary.

How write downs affect your out-of-pocket costs

Write downs lower your out-of-pocket costs because they reduce the approved amount you owe coinsurance on. If a doctor's charge is $200 but the approved amount is $120, your 20 percent coinsurance is $24, not $40. The write down saves you money by keeping your cost-sharing calculation based on Medicare's approved amount, not the doctor's full charge.

This is why Medicare participation protects your wallet. A non-participating doctor could charge $200, and if you are unaware they do not participate, you might end up responsible for the full amount or a much larger coinsurance percentage. Participating doctors' write downs are built into the system to keep your costs predictable.

Frequently Asked Questions

Can a doctor bill me for the write down amount?

No. If the doctor accepts Medicare, they have agreed to accept the approved amount as payment in full. They cannot bill you for the write down. If a doctor bills you for a write down, contact Medicare or your state's insurance commissioner to report it.

Does the write down count toward my deductible or out-of-pocket maximum?

No. Only the approved amount counts toward your deductible and out-of-pocket maximum, not the write down. The write down is straightforward removed from the calculation. This is another reason write downs benefit you — they do not add to your cost-sharing obligations.

What if I see a non-participating doctor — will there be a write down?

No. Non-participating doctors do not accept Medicare's approved amount, so there is no write down. You may be responsible for the full charge they bill, depending on whether you signed an advance notice form. Always ask if a doctor participates in Medicare before your visit.

Why is the write down amount different for the same service at different doctors?

The approved amount is the same across all participating doctors in your area for the same service, so the write down should be the same too. If you see different write downs, it may be because the doctors charged different amounts, or the services were slightly different. Your EOB will show the approved amount used for each claim.

Can I negotiate the write down with my doctor?

No. The write down is set by Medicare's fee schedule, not by individual negotiation. Your doctor cannot reduce it or ask you to pay it. If you have questions about why a particular service has the approved amount it does, Medicare's website shows the fee schedule by service and region.