Finance

Contractual Allowance & Underpayment Estimator

Model how each payer’s contract pays — per diem, case rate, percent of charges, or a flat amount — to estimate expected reimbursement, the contractual allowance, and the effective payment rate against your charges. Add what you were actually paid to surface underpayments. Everything runs in your browser — nothing is saved or sent.

EstimatorBrowser-onlyNo PHI
No PHI

Do not paste patient names, Medicare IDs, SSNs, full claim files containing PHI, or other protected health information. This tool is intended for de-identified examples and educational / reconciliation support. Everything runs in your browser — nothing you paste is stored, logged, or sent anywhere. Enter aggregate financial figures only — this runs entirely in your browser, and nothing is saved or sent. Do not enter patient identifiers.

Data statusEstimator
Status
Estimator
Data year / effective
Your figures
Last reviewed
May 2026
Last updated
May 2026
Primary source
Standard revenue-cycle formulas
Formula notes
Expected reimbursement is computed from the contract method you choose — percent of charges (charges × rate), per diem (per-diem × covered days), case rate (case rate × cases), or a flat amount. Contractual allowance = gross charges − expected. Effective payment rate = expected ÷ charges. Underpayment variance = expected − actually paid.
Known exclusions
  • Computed from the contract terms and figures you enter
  • Effective rate compares expected reimbursement to your gross charges
  • Underpayment variance is vs. your modeled expected amount, not an official allowed amount
  • Excludes bad debt, denials, patient responsibility, and sequestration unless reflected in your figures
  • Informational only — not financial or accounting advice
Browser-onlyNo PHI
New here? Load an example to see mixed contract types and an underpayment.

Model each payer’s contract

For each payer, pick how the contract actually pays — per diem × days, case rate × cases, percent of charges, or a flat amount — and enter the terms. The tool works out the expected reimbursement, the contractual allowance, and the effective payment rate against your charges. Add what you were actually paid to flag underpayments.

Summary

Total gross charges
$0.00
Expected (net) reimbursement
$0.00
Total contractual allowance
$0.00
Blended effective rate
Blended allowance %
Actual paid
Underpayment vs expected
Payers underpaid
A contractual allowance is the difference between what you charge and what a payer’s contract allows — a contractual write-off, not bad debt; the expected amount is your net realizable revenue. Because post-acute contracts often pay by per diem or case rate rather than a percentage, the effective payment rate (expected ÷ charges) is usually not obvious by eye — this tool surfaces it and blends it across payers. Entering actual payments highlights where you may be paid less than the contract implies, which is a starting point for a payer follow-up, not a determination. Informational only — not financial advice; verify against your contracts and remittances.