SNF Billing Guidelines: A Complete Reference

SNF billing guidelines are the rules and procedures that govern how skilled nursing facilities submit claims to Medicare, Medicaid, and other payers. These guidelines cover everything from admission documentation and MDS timing to UB-04 form completion, condition codes, and filing deadlines. Getting them right means getting paid on time; getting them wrong means denials, delayed revenue, and potential compliance exposure.

In This Post

• Medicare Part A billing requirements for SNFs
• Key timelines and deadlines
• UB-04 essentials — the fields that matter most
• Common billing errors that cause denials
• Medicaid and managed care billing differences

Medicare Part A: The Foundation

Medicare Part A is typically the highest-paying payer source for SNFs, which is exactly why billing it correctly matters so much. A Part A covered stay requires:

• A qualifying 3-day inpatient hospital stay (midnight to midnight, not observation)
• Admission to the SNF within 30 days of hospital discharge
• Skilled nursing or therapy services needed on a daily basis
• Services that can only be provided in a SNF setting (or that are more practical and efficient there)
• A physician’s order for skilled services and a plan of care

The MDS assessment drives the PDPM classification and HIPPS code, which determines the per diem rate. Your billing staff submits claims on the UB-04 form using the HIPPS code generated from the MDS. Timing is critical — assessments have specific reference dates and windows, and late or missing assessments can result in default rates that dramatically reduce payment.

Key Timelines Every BOM Should Know

• 5-Day Assessment: Reference date between days 1-8 of the stay
• Interim Payment Assessments (IPA): Required if there’s a significant change affecting payment
• Claim submission deadline: Claims must be received within 12 months of the date of service (1 calendar year)
• Demand bills: Due within 1 year of the date of service
• Medicare Secondary Payer claims: File to the primary payer first, then to Medicare with appropriate condition codes

UB-04 Fields That Cause the Most Problems

Based on our experience reviewing hundreds of SNF claims, these are the UB-04 fields where errors are most concentrated:

• Type of Bill (TOB) — Must be correct for the type of claim (211 for admission through discharge, 212 for interim, 214 for final)
• Condition Codes — Wrong or missing condition codes are a top denial reason (e.g., Condition Code 04 for managed care informational claims)
• Occurrence Codes — Code 27 (date benefits exhausted) is frequently missing or wrong
• Revenue Codes — Must match the services billed and align with the HIPPS code
• Patient Status — Must accurately reflect discharge status; errors here trigger audits

Top Reasons SNF Claims Get Denied

• Lack of medical necessity documentation — the chart doesn’t support skilled care
• Timely filing — claim submitted after the 12-month window
• MDS/billing mismatch — HIPPS code on the claim doesn’t match what’s in the MDS system
• Missing physician certification or recertification
• Eligibility issues — resident wasn’t eligible for the benefit period claimed
• Consolidated billing violations — outside provider billed for an included service

Medicaid and Managed Care: Key Differences

Medicaid billing varies by state, but some universal principles apply: Medicaid generally requires prior authorization, has its own rate structure (usually lower than Medicare), and often has shorter filing deadlines. Your Business Office needs state-specific knowledge for every state where your facility operates.

Managed care (Medicare Advantage) plans each have their own contracts, authorization requirements, and appeal processes. Never assume an MA plan follows the same rules as Traditional Medicare — because they don’t. Check your contracts.

The Bottom Line

SNF billing is a specialized skill set. The rules are complex, the deadlines are tight, and the consequences of errors range from delayed payment to compliance investigations. If your Business Office team is struggling with denials, aging reports that keep growing, or simply not having enough hours in the day to manage it all, that’s exactly the situation we help facilities navigate.

Contact SNF Solutions for a free consultation or call 407-977-8878.

— Nicole