The overwrite bug
Updating a price in place means every open file silently re-prices. Yesterday’s admission bills at today’s rate; disputes follow in both directions. Versioned rate cards — effective-dated, never overwritten — make every bill reconstructible.
Payer cards drift apart
Each payer contract amends independently. The hospital running “one master card with exceptions in someone’s head” is the hospital whose billing depends on who is on shift. Every payer gets its own dated card in the system.
| Item | Standard | Consequence / owner |
|---|---|---|
| Effective dating | Every change carries a from-date | No silent re-pricing |
| Version retention | Old cards never deleted | History reconstructible |
| Per-payer cards | Contract amendments isolated | Cross-payer bleed stops |
| Treatment-date pricing | System picks the version | Shift-independent billing |
| Change log | Who, when, what | Audit in one query |
The audit answer
“Why this price?” should be answerable in one query: card version X, effective date Y, treatment date Z. If the answer requires narrative, the next deduction is already scheduled.
What to do on Monday
- Check: does your system overwrite or version tariffs?
- Split payer cards that share one master today.
- Test one old bill: can you reconstruct its pricing?
Worked examples on this page are illustrative arithmetic on stated assumptions, not measured market statistics.