Eligibility & prior-auth API · in development
Cleared means paid.
The eligibility and prior-authorization API that returns a guarantee, not a probability. If Undersign clears an encounter and the payer denies the claim anyway — for an eligibility, coverage, or authorization reason — we pay you the contracted claim value within 30 days. And we handle the appeal.
$ POST /v1/clearance
{ "payer_id": "aetna",
"member_id": "W88231945",
"cpt": "90837",
"service_date": "2026-09-14" }
→ 200 OK · 142ms
{ "decision": "cleared",
"guarantee_id": "grt_01J9ZKQ4T7",
"guaranteed_value_cents": 18400,
"expires": "2026-10-14" }cleared is not a score. It's a signed obligation.
days to payment
on denied-but-cleared claims
basis-point pricing
pay for certainty like interchange, not like software seats
of initial denials
are eligibility, coverage, or auth — knowable at intake
the appeal is ours
your team never opens the work queue
Why this is different
Everyone else tells you the odds.
We sign the outcome.
Eligibility vendors sell you accuracy percentages. Prediction engines sell you confidence scores. Either way, when the denial comes back, it's your denial. That's the liability line. Every verification company in healthcare stops at it. Undersign crosses it.
Verification vendors
“The patient is eligible — 96% accurate.”
The 4% is your problem.
sells informationPrediction engines
“This claim will probably be paid.”
The odds are your problem.
sells probabilityUndersign
“This claim is cleared. If we're wrong, we pay.”
The outcome is our problem.
sells certainty — signedWe don't predict denials. We pay for them.
One API call at intake
Verify. Clear. Signed.
Verify
At scheduling or intake, one call runs real-time eligibility (X12 270/271), benefits discovery, and prior-auth status against the payer's actual rules — not a cached snapshot.
Clear
Our underwriting engine runs every encounter through 14 ordered rules — payer behavior, plan status, auth requirements, exposure limits. The answer is cleared, step_up, or declined. No maybes.
Signed
A cleared decision issues a guarantee with a content-addressed, hash-chained evidence record. If the payer denies anyway, the guarantee pays the contracted claim value within 30 days — and our team owns the appeal.
Every guarantee is frozen with its evidence at decision time. Auditable by you, by us, by anyone.
The denial tax
You're already underwriting denial risk.
You're just not getting paid for it.
of initial denials are eligibility, coverage, or authorization problems — knowable at intake
rework cost per denied claim
of denied claims are never resubmitted — abandoned revenue
of appealed denials eventually get paid. The denial wasn't real. The labor was.
The industry spends $43–45B a year checking eligibility — and still eats the denials. Checking was never the product. Certainty is.
What's covered
If it was our call, it's our check.
Covered
Denials for eligibility (patient not covered at service date), coverage (service not a plan benefit), and prior authorization (auth missing or invalid) — the failure modes an API can verify before care happens.
Not covered
Coding errors, clinical documentation, contractual write-offs — the parts of the claim we never touched.
The terms
Contracted claim value. Paid within 30 days of the denial. We run the appeal at our expense. Priced in basis points of guaranteed claim value.
Who it's for
Denials aren't generic.
Neither is the guarantee.
Behavioral Health
Denied ~85% more often. Guaranteed anyway.
Telehealth & digital health platformsTelehealth & Digital Health
Embed guaranteed coverage in intake.
PT · OT · Speech therapyPT / OT / Speech
Guarantee the plan of care.
Outpatient imagingOutpatient Imaging
Covered before the table.
Home & ambulatory infusionInfusion
Five figures, cleared first.
Home healthHome Health
Guarantee the episode.
Why us
The wire format and the risk math, under one roof.
A payment guarantee needs exactly two skills: parsing healthcare's wire formats, and underwriting its risk. We're one of each — and brothers.
Corey Nyako
EngineeringBuilt federal-scale health-data pipelines at the CDC. Speaks X12 fluently.
Simon Nyako
UnderwritingCredentialed healthcare actuary. Prices risk for a living.
Software companies have the data but no risk capital. Insurers have the capital but can't parse the wire. Undersign is both.
The API is in development
Be first on the ledger.
We're building Undersign in the open, measuring denial outcomes in shadow mode before a single guarantee is priced. Leave your details and we'll send pilot updates — and first access when clearance goes live in your market.