26th-of-the-Month Billing Convention and Cutoff Dates

A 26th of the month billing cutoff is an internal deadline that closes the current billing period on the 26th rather than the last calendar day. Anything documented through the 26th belongs to that period; anything recorded on the 27th or later rolls into the next one. The days between the 26th and month-end become a working window for reconciling accounts, verifying claims, and catching errors before submission. The convention shows up most often in Medicare Skilled Nursing Facility billing, though some payroll and utility operations use similar early cutoffs.

How the Cutoff and Billing Window Work

The billing window under this convention runs about thirty days. It opens on the 27th of one month and closes at the end of the 26th of the next. A period that starts March 27 captures services through April 26. A therapy session on the 26th and a therapy session on the 27th land on different claims, potentially with different payment timelines.

This is not a federal rule. It’s an organizational practice, and your specific cutoff depends on your payer, your facility’s internal policy, or your service agreement. When your internal records don’t line up with the cycle your payer expects, the usual result is a denied claim you have to resubmit, and resubmission means waiting through another full processing cycle.

Why Medicare SNF Billing Uses an Early Cutoff

The Balanced Budget Act of 1997 created a consolidated billing requirement for Skilled Nursing Facilities. Under that requirement, the facility submits all Medicare claims for services its residents receive, rather than letting outside suppliers bill Medicare directly. The SNF furnishes services either itself or through outside arrangements, but the SNF handles the billing.¹

SNF claims go to Medicare monthly. A facility bills at the close of each monthly period, upon discharge, when benefits are exhausted, or when the patient no longer needs skilled care. Physical, occupational, and speech-language therapy remain subject to consolidated billing regardless of whether the resident is in a covered Part A stay.¹ Because so many services have to be bundled into a single monthly claim, an internal cutoff a few days before month-end gives the billing department time to compile everything accurately.

What Goes on the Monthly Claim

An accurate monthly claim needs the patient’s account or health insurance claim number, the precise dates of service, and the correct procedure codes. Medicare claims use HCPCS or CPT codes to identify each service, along with the National Provider Identifier for every provider involved in the care.

Most institutional providers submit on the UB-04 form, also known as the CMS-1450. The Statement Covers Period field, Form Locator 6, takes the beginning and ending dates of the billing period. If your organization runs a 26th-of-the-month cycle, those from-and-through dates need to match the internal cycle rather than the calendar month. Before submitting electronic claims, every provider has to complete the CMS Electronic Data Interchange enrollment form and file it with the local Medicare Administrative Contractor, whether claims go out directly or through a clearinghouse.²

When the 26th Falls on a Weekend or Holiday

The effective cutoff shifts when the 26th lands on a weekend or federal holiday. Most organizations move it to the preceding business day, usually Friday, so that electronic transfers and claim submissions happen during standard banking hours. Some organizations extend to the following Monday instead, depending on their service agreements.

The Automated Clearing House system doesn’t settle transactions on weekends or Federal Reserve holidays.³ A claim submitted electronically on Saturday won’t begin processing until Monday. If your payer counts submission date rather than receipt date, that gap can push a claim into the next cycle. Check your service level agreement or MAC guidance to confirm which direction your deadline moves. The wrong assumption can cost a full month of cash flow.

The 12-Month Outer Deadline

Whatever internal cycle your organization runs, Medicare imposes an absolute outer limit: all fee-for-service claims must be submitted within 12 months of the date services were furnished.⁴ Miss that window and the claim is denied as untimely, and that denial is not subject to appeal.

The 12-month clock starts on the date of service, the “From” date on the claim. For institutional claims with span dates, the “Through” date is used instead. A handful of narrow exceptions can extend the deadline by six additional months, including situations where a Medicare contractor gave you incorrect information, where a beneficiary received retroactive Medicare entitlement, or where a patient was retroactively disenrolled from a Medicare Advantage plan.⁴

An early monthly cutoff is meant to prevent drift toward that outer limit. If claims sit past an internal deadline and the delay compounds over several months, the one-year cliff gets uncomfortably close.

Fixing Errors After the Cutoff

Mistakes happen under monthly time pressure. If you catch a clerical error, such as a transposed code, an inaccurate data entry, or a wrong provider number or date of service, you can request a claim reopening at any time, provided the initial determination was at least partially unfavorable.⁵ Clerical error covers mathematical mistakes, transposed procedure or diagnostic codes, computer errors, and similar data problems. Errors made by a third-party payer do not qualify.

The “at any time” language is generous on paper. In practice, CMS warns that contractors are not expected to routinely grant reopening requests, especially for older claims where the claims history may no longer be readily available.⁵ The sooner you catch and correct a mistake, the smoother it goes.

If a claim is denied and you want to challenge the denial, you have 120 days from the date you receive the initial determination notice to request a redetermination. CMS allows a five-day grace period beyond the 120 days for mail delivery. After that, you have to show good cause for a late filing, and extensions are not routinely granted. Medicare Advantage reconsideration windows are shorter at 60 days from the date of the organization’s determination, and Medicare drug plan coverage determinations also carry a 60-day deadline.⁶

Interest When the Payer Pays Late

When the government pays late, the Prompt Payment Act requires federal agencies to pay interest on overdue invoices. The rate for January through June 2026 is 4.125%.⁷ Interest accrues from the day after payment was due through the day it is actually made.⁸

For Medicare, interest is owed on clean claims if payment is not made within 30 days of receipt. Treasury sets this rate on a six-month basis, effective each January 1 and July 1. The rate for the first half of 2026 matches the Prompt Payment rate at 4.125%. Interest is supposed to be automatic. Monitoring your claims through the MAC portal is the practical way to catch payment delays early enough to act on them.

One nuance: temporary unavailability of funds does not excuse an agency from paying interest penalties. If your payment is late because of a budget issue on the government’s side, you are still owed interest.⁸

1
Centers for Medicare & Medicaid Services. Skilled Nursing Facility (SNF) Consolidated Billing
2
Centers for Medicare & Medicaid Services. How to Enroll in Medicare Electronic Data Interchange
3
Federal Reserve Financial Services. Federal Reserve System Holiday Schedule
4
Centers for Medicare & Medicaid Services. Medicare Claims Processing Manual – Changes to the Time Limits for Filing Medicare Fee-For-Service Claims
5
Centers for Medicare & Medicaid Services. Medicare Claims Processing Manual, Chapter 34 – Reopening and Revision of Claim Determinations and Decisions
6
Medicare.gov. Medicare Appeals
7
Bureau of the Fiscal Service. Prompt Payment
8
Office of the Law Revision Counsel. United States Code Title 31 – Section 3902