Remark code

M80 remark code: not covered with another same-day service

M80 is a remittance advice remark code that says the service is not covered when performed during the same session or on the same date as a previously processed service for the patient. The fix depends on whether the two services were truly separate encounters or one service reported twice.

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Written by Salman Saeed, CEO and Co-Founder · Reviewed by a Certified Medical Coder · Last reviewed October 2026

M80 at a glance

Code typeRARC (remittance advice remark code)

DescriptorNot covered when performed during the same session/date as a previously processed service for the patient.

X12 start date01/01/1997 (last modified 10/31/2002)

Type in X12 listNo Alert label (not an alert)

What it comparesThis line against a service already processed for the patient

Medicare rule to checkNCCI Policy Manual chapter I, modifier indicators 0, 1, 9

Fix pathClassify duplicate, bundled pair or separate encounter

In short: M80 flags a service because another service for the patient was already processed for the same session or date. Decide whether it is a duplicate, a bundled pair or a real separate encounter, then correct, add a supported modifier, or accept the adjustment.

What does the M80 remark code mean?

X12 lists M80 as: "Not covered when performed during the same session/date as a previously processed service for the patient." The entry shows a start date of 01/01/1997 and a last-modified date of 10/31/2002, with no "Alert:" label. It is a remittance advice remark code (RARC), so it explains an adjustment rather than creating one.

Read the wording closely. It compares the service on this line with a service the payer already processed for the same patient in the same session or on the same date. It does not say the earlier service was on your claim, the same code, or from your practice. The earlier line is a different thing from the one you are looking at, and you have to find it. Reviewed October 25, 2026.

What is the earlier service, and which kind of M80 is it?

Three situations can sit behind a same-session remark, and the correction is different for each. Check them in this order.

Situation	What to look for	Where to go next
Same service reported twice	Same code, same date, same patient on two claims or two lines	CO-18, the exact duplicate
Two services the payer treats as one	A code pair in an edit table, with the second code adjusted	CO-97 and CO-236
Two truly separate services	Different encounters or sites that the claim does not show	The modifier rules below

X12 does not tie M80 to one adjustment reason, so the table is a way to sort your own remits, not a list of official pairings. Your remit shows which adjustment reason sits beside the remark.

When can a modifier separate the two services?

For Medicare, the NCCI Policy Manual, chapter I, governs most same-date pairs. It says that when both codes of an edit pair are reported, the Column One code is eligible for payment and the Column Two code is denied, unless it is clinically appropriate to use an NCCI PTP-associated modifier.

The manual gives the limits. A modifier may be appended only if the clinical circumstances justify it, and never solely to bypass an edit. Each PTP edit carries a correct coding modifier indicator. A value of 0 means associated modifiers cannot bypass the edit, 1 means they may under appropriate circumstances, and 9 means use is not specified. In general, the manual says the justifying circumstances relate to separate patient encounters, separate anatomic sites or separate specimens.

Modifiers 22, 76 and 77 are not PTP-associated modifiers, and the manual says they do not bypass a PTP edit. See modifier 59 for distinct procedural services.

How do you respond to M80?

Find the earlier service

Search the patient's claims for the same date and session. Include other providers in your group and other lines on this claim.

Classify it

Duplicate, bundled pair or separate encounter. If it is a duplicate, withdraw the second submission instead of defending it.

Check the claim fields

CMS-1500 item 24A carries the dates, item 24D the code and up to four modifiers, as chapter 26 of the Claims Processing Manual describes. A wrong date or a missing modifier is a data problem you can correct.

Choose the route

If the record supports a separate service and the indicator allows a modifier, send a corrected claim. If it does not, accept the adjustment under the contract rules. For a Medicare disagreement after review, see the appeal levels.

Example: made-up claim, illustrative only

A patient has two procedures on one date at two body sites, both billed on separate claims a day apart.

RemitSecond claim line adjusted with M80

ReviewOperative notes show separate sites and the edit allows a modifier

FixCorrected claim with the supported modifier and documentation on file

How does M80 read on the remittance?

M80 is a remark, not a reason code, so it rides with a CARC such as 97 or 236 in the LQ segment of the line. It compares this line with a service already processed for the patient. Read the indicator for the pair in NCCI chapter I (0, 1 or 9) before you add a modifier.

A simplified remittance line with the group code, claim adjustment reason code, adjustment amount and remark code marked — Simplified, not a real 835. Read the group code, the CARC and the remark together on the same line.

Where does M80 appear?

Any specialty that bills several services on one date sees it, so dermatology billing, physical therapy billing and radiology billing teams check same-date lines before resubmitting. If the claim is instead returned incomplete, see MA130. For missing modifiers, see N822, and for a missing rendering identifier, N290. Back to the code library. If these denials keep coming back, our denial management team can work them.

CO-97 Included in another service CO-18 Exact duplicate CO-236 NCCI incompatible pair N822 Missing procedure modifier

Sources

We check every rule, code and deadline against the official source. See our editorial policy.

FAQ

Common questions

Straight answers from the team that does the work.

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01What does M80 mean about same-session services?

M80 means the payer treated the service as not covered because another service for the same patient was already processed in the same session or on the same date. Find the earlier service, decide whether it is a duplicate, a bundled pair or a separate encounter, and respond accordingly.

02Is M80 the same as an NCCI denial?

Not by definition. X12 words M80 around a previously processed same-session or same-date service and does not mention NCCI. An NCCI edit can produce a same-date adjustment, so check your remit for the adjustment reason beside it. Chapter I of the NCCI manual governs those pairs for Medicare.

03Can a modifier fix M80?

Sometimes. The NCCI manual allows PTP-associated modifiers only when clinical circumstances justify them and the edit's indicator is 1. With an indicator of 0, no modifier bypasses the edit. A modifier added only to get paid is not allowed, so the record must support separate encounters or sites.

04What if the earlier service was on a different claim?

The X12 wording refers to any previously processed service for the patient, so the earlier line may sit on another claim. Search by patient and date of service, including other clinicians in your group. If it is the same service twice, withdraw the later submission.

05Should I appeal M80?

Appeal only after you have confirmed the service was separate and the record supports it. If a modifier or date was wrong, a corrected claim is the fix, not an appeal. For Medicare disputes, see the appeal levels page for the order and the deadlines.