Underpayment recovery for hospitals
Slingshot checks every payment against your payer contracts and recovers the difference — including the thousands of small balances too costly for people to chase. You pay only on what we collect.
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Market metrics
U.S. health spending in 2024 — 18% of GDP, or $15,474 per person.
CMS National Health Expenditure Accounts
Health insurance premium revenue reported to regulators in 2024.
NAIC filings, via Mark Farrah Associates
Hospital care spending in 2024, up 8.9% — the largest single slice of U.S. health spending.
CMS National Health Expenditure Accounts
The cost of getting paid
spent by hospitals in 2025 collecting payments insurers owed for care already delivered.
AHA Costs of Caring, 2026
of that spent overturning denied claims.
AHA Costs of Caring, 2026
in claims six months or older and still unpaid, across 772 hospitals surveyed.
AHA survey of commercial insurer practices, 2022
of hospitals carry more than $100M in receivables older than six months.
AHA survey of commercial insurer practices, 2022
Denials rose 20.2% on commercial claims and 55.7% on Medicare Advantage claims between 2022 and 2023, while administrative work now runs above 40% of what hospitals spend to deliver care. Slingshot exists for the gap in between.
Sources: CMS National Health Expenditure Accounts, 2024 · NAIC accident & health filings, 2024 · AHA Costs of Caring, 2026 · AHA survey of commercial insurer practices, 2022 · AHA report on administrative costs, 2024
Contract-aware detection
Paid off last year's rates or the wrong contract tier.
Modifiers that should raise payment, silently dropped.
Carve-outs and outlier terms calculated incorrectly.
Reductions your contract doesn't allow.
Retroactive denials
When a payer authorizes an operation, the approval often carries a proviso at the bottom: the right to revoke the authorization later if they "find a reason to." Months after care is delivered, they use it — denying services they approved, after the fact. Slingshot is built to fight exactly this.
We pull the authorization number, date, approved CPT codes and any “not a guarantee of payment” language — so the promise on paper is pinned down word for word.
A mismatch between what was authorized and what was later denied is the strongest evidence in the file. We surface it line by line.
State-regulated HMO, state-regulated insurer, self-funded plan, Medicare Advantage or Medicaid — the legal arguments differ for each, so every claim is flagged before a word is written.
For a Texas HMO claim, the appeal cites the preauthorization statute and the retrospective-review notice requirements — including the 45-day retrospective-review clock, which our triage tracks like any other deadline.
The authorization letter, the surgeon's note and the claim are packaged into a single exhibit, so the reviewer sees “authorized it, now revoking it” at a glance.
Appeal templates are reviewed by counsel, and every output is labeled an appeal aid — not legal advice.
A worked example
This is a synthetic denial letter — the kind hospitals receive every day. On the left, what the payer sent. On the right, what Slingshot does with it.
BlueHarbor Health Plan
Claims & Appeals Department · Anytown, ST
Notice of claim denial · Oct 28, 2026
Reason for denial
"Prior authorization was not obtained before the date of service… Our records show no authorization request on file."
CARC CO-197 · RARC N54 · Plan provision §4.2, "Services Requiring Prior Authorization"
Appeal window: 180 days — due April 26, 2027. Fictional notice; no real patient data.
Read the denial, line by line
We extract the claim number, the adjustment codes (CO-197, N54), the plan provision cited (§4.2) and the appeal clock — 180 days, due April 26, 2027 — and start tracking it immediately.
Match the code to a denial category
CO-197 with N54 is a prior-authorization denial, not a coding or medical-necessity denial. The category decides what evidence counts, so only the relevant set is pulled — not the whole chart.
Flag missing documents before drafting
The required set is checked against the record first. Anything absent is flagged to a human before a letter is written, so we never file an appeal that quietly answers the denial with silence.
Evidence set · Prior authorization
Pulled automatically from CARC CO-197 / RARC N54.
One item not found. Flagged for a human before drafting; nothing is filed until it is located or deliberately waived.
Check the payer's own rules
Did this plan actually require prior auth for CPT 72148 under §4.2? Payers misapply their own provisions more often than you'd think.
Pre-fill the appeal letter
Claim number, dates, codes, the provision cited and the evidence bundle are filled in automatically. A certified coder or analyst reviews and sends — the draft is never the outbound document.
File, follow up, escalate
The appeal goes to the plan's Appeals Department with the deadline tracked in triage. If it's denied again, we prepare the independent external review.
The recovery loop
Six moves, every time — one denial or ten thousand. The deadline tracker runs underneath the whole loop, not as a step at the end.
It compounds. Every outcome — paid, partially paid, upheld — is logged against payer and reason code, so the next classification is sharper and the next letter is better argued.
Running throughout
Every clock in the file, watched from intake to filing.
Notice, remits and the contract clause land in one record.
CARC, RARC and reason text set the denial category.
Only the documents that category actually requires.
Missing items go to a human before anything is drafted.
A rebuttal tied to the payer's own policy language.
Coder, analyst or counsel — whoever owns this claim.
Ingest the denial
Notice, remits and the contract clause land in one record.
Classify it
CARC, RARC and reason text set the denial category.
Pull the evidence set
Only the documents that category actually requires.
Flag the gaps
Missing items go to a human before anything is drafted.
Draft the letter
A rebuttal tied to the payer's own policy language.
Route for sign-off
Coder, analyst or counsel — whoever owns this claim.
Deadline tracker
Runs the whole time — appeal window, timely-filing limit, retrospective-review deadline.
Send 835/837 files, an aging report and your payer contracts. No new software, no IT project.
Every line is repriced against your contract. Underpayment = expected minus paid, claim by claim.
Ranked by value × payer win rate × filing deadline — including the small balances nobody works today.
Citation-linked disputes go out, follow-up runs until paid, and every step is logged for audit.
Humans can't profitably chase a $300 underpayment. Software can, across thousands of claims at once.
We learn win rates and tactics by payer and reason code, so each dispute is better informed than the last.
No rip-and-replace. We read the files your system already produces.
Disputes cite the contract clause, remit line and record they rely on — an audit trail for compliance and payer pushback.
Security & compliance
Built to HIPAA requirements; we sign a Business Associate Agreement before receiving any data.
Audit in progress.
Encrypted in transit and at rest, minimum-necessary access, US-hosted, deleted on request at contract end.
A certified coder reviews every code change before anything is resubmitted. We never alter codes automatically.
No subscription, no setup fees. We take a percentage of what we collect — nothing recovered, nothing owed. For aged balances, we can also purchase receivables at a discount for immediate cash.
[ Founder name ], [ background in revenue cycle / healthcare / AI ]. Built with input from practicing surgeons and hospital billing leaders. [ Advisors / customers ].
Send an aging report or 835 file. We'll return a free underpayment estimate.