Nursing Home Billing Guidelines & Codes for Proper Reimbursement

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File an amended claim with a -Claim Adjustment Reason Code (CARC) and documentation.

The 3-Midnight Rule: Medicare guideline for SNF qualification. To qualify, a patient must:
Have stayed in a hospital as an inpatient for at least 3 straight midnights (observation stays don’t count).

• Admit to SNF within 30 days of hospital discharge.\
• Need skilled services (such as rehab therapy or wound care).

Example: A patient hospitalized for 3 nights after a hip replacement can transition to SNF for rehab under Medicare Part A.

Pro Tip: Observation stays do not count toward the 3-midnight rule. Confirm hospital status before billing.

Yes. Medicare applies firm billing guidelines for SNFs, including:

• MDS 3.0 Assessments:Required for Medicare reimbursement (submitted within 14 days of admission).
• RUG-IV Codes:Determine payment tiers based on care complexity (e.g., “Ultra-High Rehabilitation”).
• Physician Certification:A doctor must certify the need for skilled care every 30 days.
  Common Errors:
• Incorrect Type of Bill (TOB)codes (e.g., using 21X instead of 22X for swing beds).
• Missing documentation for medical necessity.

Key codes for SNF billing include:

• CPT Codes:
  • 99304–99310: Evaluation and management (E/M) visits for nursing assessment and care.
  • 99318:Annual nursing facility assessment.
• TOB Codes:
  • 21X:SNF inpatient claims.
  • 22X:Swing bed services.
• RUG-IV Codes:Classify care intensity (e.g., “SE3” for extensive services).
• Modifiers:
  • -25:Separate E/M service on the same day.
  • -GV:Non-hospice physician services.

Example: A 45-minute follow-up for a SNF resident with pneumonia would use 99309 (high-complexity subsequent care).

• Medicare Part A: Provides coverage for up to 100 days in SNF care (days 1–20: fully covered; days 21–100: copay needed).
• Medicaid: Pays for extended care for eligible low-income individuals (varies by state).
• Private Insurance/Out-of-Pocket: Pays for services not included under Medicare or Medicaid.
• Resident/Family: Pays for copays, uncovered services, or private-pay care.

Example: After 100 days in an SNF, the resident or their family must pay all expenses unless Medicaid applies.

Pro Tip: Always verify eligibility and coverage limits before admission to avoid surprises.