N115 Remark Code: Meaning, Every CARC Pairing, and Fixes

N115 is a remittance advice remark code. It means the payer based the decision on a Local Coverage Determination, a coverage policy set by a Medicare Administrative Contractor for its own jurisdiction. The N115 remark code usually rides next to CARC 50 or CARC 96 on the remittance. Fixing it starts with finding that LCD, checking the diagnosis and documentation against it, then correcting the claim or filing an appeal.

What does the N115 remark code mean

The X12 standards body maintains the remittance advice remark code list under HIPAA, and its official text for N115 states the decision was based on a Local Coverage Determination. A Medicare Administrative Contractor issues an LCD to define whether a specific item or service counts as reasonable and necessary within that contractor’s own jurisdiction.

An earlier CMS transmittal used a different name for this same mechanism. It called it a local medical review policy, or LMRP, before the field settled on Local Coverage Determination.

CMS updates the national RARC and CARC lists X12 several times a year, most recently effective July 1, 2026. N115’s own wording has held steady since 2010.

Where N115 shows up on the 835 remittance file

At the service line level, N115 reports in the 835 LQ segment. A claim-level version of the same remark reports in the MOA or MIA segment instead. Anyone reconciling posting software against a raw 835 file needs to know which segment to check.

N115 remark code versus the codes it gets mistaken for

The number and letters in N115, sometimes shown as N-115 or N 115 depending on the system pulling the remittance, do not automatically point to a coverage policy. Two other codes share pieces of that string and mean something else entirely.

Only N386 shares N115’s actual logic. CARC 115 and M115 just share its number.

N115 versus N386: local policy versus national policy

N386 works the same way N115 does, one level up. A Medicare Administrative Contractor issues the Local Coverage Determination behind N115 for its own jurisdiction. CMS issues the National Coverage Determination behind N386 for the whole country. A biller who checks the wrong policy level wastes the appeal window on rules that were never the ones in play.

Which CARC codes pair with N115

Every CARC that pairs with the N115 remark code points to a different reason the LCD was not met.

Seeing N56 alongside N115 on the same line signals a CARC 96 denial where the procedure code itself was invalid for the date of service. N115 names the coverage policy behind that same decision.

Which CARC shows up depends on the specific reason the LCD was not met. A frequency problem produces CARC 150 or 151. Documentation gaps tend to produce CARC 50. A procedure code that never belonged on the claim produces CARC 96 or CARC 11.

CO-50 is the pairing that shows up most often. The CO-50 denial code guide covers exactly what that combination looks like on a real remittance.

Why N115 denials happen

Four causes account for most N115 denials, and none of them involve a provider doing something wrong clinically.

• The diagnosis code submitted is not on the LCD’s covered indications list for that service.
• The service went past a frequency limit the LCD sets, the CARC 150 and 151 scenario made concrete.
• The documentation does not demonstrate medical necessity the way that specific LCD defines it, which differs from documentation simply being missing.
• The claim used billing criteria from an outdated version of the LCD, since a Medicare Administrative Contractor revises policy on its own timeline.

Every one of those four causes is the same problem wearing a different coat. The claim never proved, on paper, what that specific LCD required it to prove.

What an N115 denial costs your practice

An N115 remark code denial costs more than the line item it appears on. Someone has to stop, pull the cited LCD, compare it against the chart, then decide between a corrected claim and an appeal. That is staff time the practice already budgeted for something else.

When the underlying cause is a frequency limit, the exposure rarely stops at one claim. The same denial can recur for the same patient every month until someone fixes the ordering or documentation pattern causing it. Left unworked past the appeal window, that claim stops sitting in accounts receivable and turns into revenue the practice will not recover.

When the same N115 denial keeps surfacing on the same service line, the real fix is a root-cause review. That means finding the specific LCD the practice keeps missing, and why.

How to resolve an N115 denial

Resolving denial code N115 comes down to four decisions, made in order.

First, locate the exact Local Coverage Determination the denial cites. The remittance or the payer portal usually names the specific LCD number directly, or the CPT or HCPCS code and the Medicare Administrative Contractor jurisdiction can be searched against the CMS Medicare Coverage Database.

Second, compare the claim against that LCD’s actual requirements: the covered diagnosis codes, the frequency limit, and the documentation it demands.

Third, decide whether this is a coding mismatch or a genuine coverage failure. When the diagnosis and procedure were both correct but did not align on the claim form, that usually points to a CO-11 diagnosis-procedure mismatch rather than a true LCD failure, and it resolves through a corrected claim instead of an appeal.

Fourth, act on what the documentation supports. If it supports medical necessity under the LCD but was not reflected on the original claim, correct and resubmit it.

When the service falls outside the LCD’s covered indications entirely, an appeal citing the specific policy language is the only path, naming the exact LCD criteria rather than a general statement of disagreement. Once it is filed, that appeal becomes a tracked follow-up item until the payer responds.

Changing a diagnosis code to one the LCD happens to cover, when the medical record does not support that diagnosis, creates a coding integrity problem. When documentation does not support the LCD, a write-off is the correct move, unless an Advance Beneficiary Notice was signed before the service was delivered, in which case the patient can be billed instead.

How to prevent N115 denials

Check the applicable LCD before delivering the service, while there is still time to change course. Nerve conduction studies, certain therapy visit counts, and sleep studies are the recurring examples where frequency limits catch practices off guard.

Build the LCD’s covered-diagnosis list into the claim-scrubbing step itself. That way, a mismatched diagnosis flags before submission instead of after a denial forces the review.

When a service looks likely to fall outside the LCD, get an Advance Beneficiary Notice signed before delivering it. The patient then understands the financial responsibility up front, instead of the practice absorbing a mandatory write-off later.

A Medicare Administrative Contractor revises its LCDs on its own schedule. Coding a claim correctly against last year’s policy does not guarantee it clears this year’s version, which is why this needs to be a recurring habit rather than a one-time setup.

Checking the payer’s own governing document before billing follows the same discipline behind remark code N130, which flags when a plan’s benefit documents needed review first.

Does N115 only apply to Medicare claims

The N115 remark code is not exclusive to Medicare fee-for-service claims.

Some non-Medicare payers adopt a specific Medicare Administrative Contractor’s Local Coverage Determination as their own coverage standard instead of writing an independent policy. When they do, N115 still appears on the remittance, pointing back to that adopted MAC policy, even on a claim that was never billed to Medicare at all.

A Minnesota health plan documented exactly this in a 2022 provider bulletin, naming National Government Services as the Medicare Administrative Contractor whose Local Coverage Determination criteria it enforces for CARC 11, CARC 96, and CARC 167 combinations with N115. This is one documented example, not a claim that every non-Medicare payer works this way.

A biller who assumes N115 always points back to their own MAC’s Medicare Coverage Database can miss the jurisdiction in play. Sometimes a commercial or Medicaid payer is pointing to a different MAC’s territory instead, one the practice does not normally work with.

The fix stays the same either way: find the specific LCD named or implied on the remittance, since the payer determines which jurisdiction to search first.

Frequently asked questions about the N115 remark code

What does N115 mean on a Medicare claim?

On a Medicare claim, the N115 remark code still means the payer’s decision traces back to a Local Coverage Determination, the regional policy a Medicare Administrative Contractor issues for its own jurisdiction. The remittance itself, or the accompanying CARC, names which specific requirement of that policy was not met.

How do I address code N115?

Find the LCD the denial cites, compare the claim’s diagnosis, frequency, and documentation against that policy’s actual requirements, then correct and resubmit the claim or file an appeal that names the specific LCD language the documentation supports.

What is a N115 denial remark?

The N115 denial code description names a Remittance Advice Remark Code, a category separate from a Claim Adjustment Reason Code. It rides alongside a CARC, most often CARC 50 or CARC 96, naming the coverage policy behind that CARC’s decision.

This is one entry in an ongoing series of denial and remark code guides from One O Seven RCM, built for the billing teams working these claims today.