CPAP cost with Medicare: what the 13-month rental costs you

Worked by hand, three months at $10.53 is $31.59, ten months at $7.90 is $79.00, and the two together are $110.59. Each rental month is a separate claim, so the 20 percent is figured and rounded to the cent on each monthly claim, not on the 13-month total; taking 20 percent of $552.85 in one step gives $110.57, $0.02 different. Medicare's side is the other $442.26. Neither number includes the humidifier, the mask or any refill, which are billed on their own lines with their own codes.

The months 4 to 13 rate is the one people tend to miss when they read a supplier's paperwork. A statement for month 2 and a statement for month 5 can show different allowed amounts for the same device code, and both can be correct. If a month after the third shows the full $52.65 again, that is worth a call to the supplier and, if needed, a look at the Medicare Summary Notice, which the EOB and notice-reading guide walks through line by line.

The deductible, and why the start month changes the bill

The $283.00 Part B deductible for 2026 (Medicare.gov, Medicare costs) is an annual amount shared by every Part B service: doctor visits, tests, outpatient care and medical equipment all draw it down together. Until it is met, you pay the full Medicare-approved amount for each service. That has an odd effect on a rental that crosses a calendar year, because the deductible starts over on January 1 and the rental keeps running.

The illustration below isolates that effect. Its stated input is unrealistic on purpose: it assumes the CPAP rental is the only Part B claim in each calendar year, so the rental alone has to satisfy the deductible. Real years usually include other Part B claims, which would meet some or all of the deductible first. Use it to see the mechanism, not as a forecast.

A January start puts months 1 to 12 in one calendar year. Those twelve months allow $513.36, so the first $283.00 is yours, and then 20 percent of the remainder. Month 13 lands in the next January, when the deductible has reset, so with no other claims that final $39.49 payment is paid entirely by you. A July start is worse in this illustration: six months fall in the first year and seven in the second, each part allows less than $283.00, and Medicare pays nothing toward the device. October sits in between.

Two lessons follow, both about money rather than care. First, if other Part B claims in the same year have already met the deductible, the rental drops straight to the 20 percent arithmetic in the earlier table. Second, the January reset can hit the last months of a rental that began late in the previous year, so when you budget for the second year, count the deductible again. The deductible and out-of-pocket guide explains how deductibles and coinsurance stack.

Is the 12-week trial inside the 13 months? The coverage text says yes

The trial is sometimes described as a free period before the rental starts. The official documents do not support that reading. National Coverage Determination 240.4 says coverage of CPAP is initially limited to a 12-week period to identify beneficiaries who benefit from it, and that CPAP is subsequently covered only for those who benefit during that period. Nothing in it describes a separate, unpaid trial.

The DME MAC documents then tie the trial to the rental months. Policy Article A52467 tells suppliers what to put on the claims for the first through third months, and what is required on the fourth month's claim and any month after. LCD L33718 requires that continued coverage beyond the first three months rests on a clinical re-evaluation by the treating practitioner no sooner than the 31st day and no later than the 91st day after starting therapy. And 42 CFR 414.230 says a period of continuous use begins with the first month of medical need. Put together: the trial months are paid rental months, and they count as months 1, 2 and 3 of the 13.

Medicare.gov's CPAP coverage page describes the same sequence in consumer terms. Medicare may cover a 12-week trial of CPAP therapy, including devices and accessories, and after the trial it may continue to cover CPAP if the beneficiary meets in person with the doctor or other provider, who documents that certain conditions are met and that the therapy is helping. The device and accessories are paid during the trial; your 20 percent applies during the trial.

The condition attached to continued payment is a documentation rule, and it is stated in the LCD with numbers. Adherence is defined as use of 4 or more hours per night on 70 percent of nights during a consecutive 30-day period anytime during the first three months of initial usage, with objective evidence reviewed by the treating practitioner. Meeting it is a clinical matter between the beneficiary and the practitioner. In billing terms, it decides who pays for month 4 onward.

What the rule does to the bill from month 4

According to Policy Article A52467, a supplier adds the KX modifier to the claims for months 1 to 3 only if the initial coverage criteria are met, and to the month 4 claim and every claim after only if both the initial and the continued coverage criteria are met. If the supplier does not have the re-evaluation and adherence information in time, it may still submit the later claims, but without the KX modifier, and LCD L33718 says continued coverage of the device and related accessories is then denied as not reasonable and necessary.

Whether you owe anything for a denied month turns on a separate form. When a supplier expects a reasonable-and-necessary denial, the article says it adds the GA modifier if it obtained a properly executed Advance Beneficiary Notice, or the GZ modifier if it did not. Claim lines without GA, GZ or KX are rejected as missing information. The Advance Beneficiary Notice guide explains what a valid ABN must contain and what the absence of one means for your liability. For a CPAP, ask whether an ABN is being signed at delivery, and keep a copy.

Timing has its own rule. If the treating practitioner's re-evaluation happens after the 91st day but shows the beneficiary is benefiting under the LCD criteria, continued coverage begins on the date of that re-evaluation. Under the policy article, a supplier that held claims and learns of a late re-evaluation may submit with the KX modifier only for dates of service after the re-evaluation. Months between day 91 and the late visit are the exposed ones.

Two more provisions round out the trial. The LCD says beneficiaries who fail the initial 12-week trial are eligible to re-qualify, but only with both an in-person clinical re-evaluation and a repeat sleep test in a facility-based setting. And because title passes after the 13th continuous month "in which payments are made," denied months are not payment months. A gap in use also matters: 42 CFR 414.230 treats an interruption of not longer than 60 consecutive days plus the days remaining in the rental month as temporary, and a longer break can start a new rental period only when the supplier submits a new prescription, new medical necessity documentation and a statement on the reason for the interruption.

The same machine at ten fee schedule amounts

The DMEPOS fee schedule is not one national price. Each state has a non-rural and a rural column, and ZIP codes in former competitive bidding areas use a separate file with an amount for each area. The table compares E0601 RR across three Michigan former bidding areas, the Michigan non-rural and rural columns, and the same layout for Florida, all from the October 2026 files (DMEPOS_OCT.csv and Former CBA Fee Schedule File - OCT2026.csv).

The rural column is far higher: $89.77 for months 1 to 3 in rural Michigan against $52.65 in non-rural Michigan, which adds $77.96 to your 20 percent over the rental with the deductible met. The background document to the 2026 files explains why. Since 2016, fee schedule amounts for many items have been adjusted using competitive bidding prices, and in rural and non-contiguous areas outside bidding areas, payment continues to blend 50 percent of the adjusted amount with 50 percent of the unadjusted amount under 42 CFR 414.210(g)(2). Non-rural areas outside bidding areas get 100 percent of the adjusted amount.

The former bidding areas follow their own rule. The competitive bidding program has been in a temporary gap, and the background document says payment in those areas is based on the single payment amounts in effect on the last day before the contracts ended, increased by the change in the consumer price index. That is why Detroit ($51.54) sits slightly below the Michigan non-rural column while Miami ($61.00) sits above the Florida non-rural column ($51.94). A ZIP code decides which column applies, and CMS publishes the former bidding area ZIP list in the same download. The same document notes that regulations at 42 CFR 414.202 define a rural area as a ZIP code with at least half of its area outside any metropolitan statistical area, plus ZIP codes inside a metropolitan area that were excluded from a bidding area.

For someone comparing suppliers, the Medicare-approved amount comes from the fee schedule column, not from a supplier's own price list, so a supplier with a higher charge does not raise it. What differs between suppliers is whether they accept assignment, and that does move your share.

The humidifier is bought, or rented only up to its purchase price

LCD L33718 covers either a non-heated (E0561) or heated (E0562) humidifier when it is ordered by the treating practitioner for use with a covered PAP device. When one is ordered, it is paid under a different class from the CPAP itself. CMS's background document places humidifiers used with CPAP among the inexpensive and routinely purchased items: if covered, they can be bought new or used, or rented, but total payments cannot exceed the purchase-new fee.

For a non-rural Michigan ZIP in October 2026, the heated humidifier is $170.34 purchased new (E0562 NU) or $17.03 a month rented (E0562 RR). Ten monthly rentals come to $170.30, essentially the purchase amount, so a rental cannot run to 13 months at that rate. Your 20 percent of the purchase amount is $34.07, paid once if it is bought, or spread across the rental months if it is rented. Ask the supplier which way it bills the humidifier, because it decides whether that cost lands in month 1 or is spread across most of the first year.

The same purchase logic applies to the supplies. Masks, cushions, tubing, filters and water chambers are category IN items billed as purchases (modifier NU) each time they are furnished, not rented.

Mask, cushions, tubing and filters: the LCD replacement schedule

LCD L33718 prints a table of the "usual maximum amount of accessories expected to be reasonable and necessary." These are ceilings, not an entitlement or a delivery calendar: quantities above them are denied as not reasonable and necessary, and quantities below them are fine. The table lists each limit with its October 2026 amounts for non-rural and rural Michigan.

Most people use one mask style, so the realistic yearly figure is one path through the table, not the whole table. The two common paths, at the usual maximum and with the Michigan non-rural amounts, are below. Both include headgear, standard tubing, both filter types and the water chamber; the nasal path uses nasal cushions (A7032) and the full face path uses full face cushions (A7031). A path built on nasal pillows (A7033) or heated tubing (A4604) changes the totals, and the per-unit figures above let you redo the sum.