The Dirty Seven: 7 Prior-Authorization Denial Codes Costing Infusion Centers the Most

Why PA denials sting infusion clinics hardest

Buy-and-bill economics magnify the impact of a rejection: a single vial can cost $4 000–$10 000, so one denied claim can wipe out the margin from a week of routine visits. Surveys of medical-group leaders rank prior authorization as the most “very or extremely burdensome” administrative task, and many practices have already hired extra FTEs just to chase approvals. Meanwhile, physicians warn that PA delays increasingly lead to serious adverse patient events—putting both financial and clinical performance on the line.

Meet the “Dirty Seven” denial codes

Seven CARC codes account for the majority of PA pain points in infusion revenue cycles:

Code

Plain-English meaning

Typical trip-wire in infusion

CO-197 / PR-197

No authorization on file

Staff never requested—or couldn’t locate—the PA ID

CO-15

Authorization number missing or invalid

Wrong ID copied from the portal or expired date range

CO-198

Units or dates exceeded

Dose adjustment or infusion scheduled after auth expiry

CO-16 + RARC M-51

Claim lacks required information

Weight, NDC11, site-of-care POS, or ICD-10 pair is blank

PR-204

Drug or service not covered

PA was denied or never submitted; patient often abandons

CO-109

Wrong payer / out-of-network

Insurance changed mid-course; claim routed to old plan

CO-18

Duplicate claim

Resubmitted while the original PA is still pending

Eliminating these seven codes from your remit typically wipes out roughly 70 % of first-pass PA denials.

The hidden cost of a “simple” rejection

Consider a mid-size infusion suite running 15 treatments per week at an average reimbursement of $4 000. A 10 % PA denial rate means 78 stalled claims a year, freezing more than $300 000 in expected revenue and $200 000 in drug inventory. If even a quarter of those patients abandon therapy after a delay, the clinic writes off nearly $80 000 outright—before counting staff time spent on appeals.

Five-step blueprint to banish PA denials

  1. Submit PAs the same day the referral lands

    Electronic 278/FHIR workflows erase the typical two-day in-house lag and keep authorizations current.

  2. Auto-insert the PA ID on every claim

    Populate Loop 2300 REF EA (institutional) or REF G1 (professional) to prevent “authorization absent” and “invalid ID” denials.

  3. Track unit and date limits in real time

    Alert schedulers when remaining units drop below 10 % or the auth expires within 14 days to avoid “units exceeded.”

  4. Front-end scrub for missing data

    Inject weight, NDC11, supervising NPI, and ICD-10 pairs before the claim ever hits the clearinghouse.

  5. Re-verify eligibility before each infusion

    Confirm active coverage for every cycle, eliminating wrong-payer and coverage-exclusion denials.

Clinics that hard-wire these steps report first-pass denial rates below 3 % and recover 55–92 % of dollars that previously ended up in bad-debt write-offs—often translating to a 15–20 % year-over-year lift in infusion revenue without adding staff.

Real-world upside

Health-system specialty pharmacies implementing same-day PA submission workflows now file more than nine in ten PAs on day one and receive payer decisions in about two days, compared with the one-week (or longer) timelines common in community practices. Other organizations report that trimming just one day off the referral-to-PA queue increases infusion revenue by roughly 10 %—about $210 000 for every ten weekly chair slots.

Bottom line

Seven denial codes create most of the financial drag in infusion therapy. Automating PA submission, capturing the correct auth ID, and monitoring unit/date thresholds turns those codes from chronic headaches into rare exceptions—freeing cash, reducing staff burnout, and keeping patients on schedule. A focused “PA Velocity Audit” can show exactly where the Dirty Seven lurk in your remit and how leading clinics have pushed them below the 3 % mark.

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2025 Trellis. All rights reserved.

2025 Trellis. All rights reserved.