Hammer LabsTwenty-five things this world will not tell you
A world model of a regulated domain is only usable if it can say “the record does not support this.” These are the 25 refusal classes the healthcare coverage world ships, at vintage AUG 31, 2026, build 13. Each is served by the world itself, as a value and not an error, with the sentence it declines to write and, where the world names it, what evidence would settle it.
Retrying a refusal returns the same refusal. Working around one by hand, having read it, is the one failure no check downstream can catch. If the first useful thing this world does is refuse a sentence, it is working.
- R-01
A denial rate or a payment probability
Not from this corpus, by any method, including arithmetic on counts the world does serve. Rate files hold negotiated rates, not adjudications. A rate’s presence does not record a payment and its absence does not record a denial.
WHAT WOULD SETTLE IT Adjudicated claims.
- R-02
Whether a payer covers a code
A published negotiated rate says what a payer pays when it pays, not whether it will. “Payer X covers code Y” is not a sentence this corpus can settle.
WHAT WOULD SETTLE IT The payer’s coverage policy, read as a document.
- R-03
A cross-payer average without declared weights
An unweighted national average is a number about this corpus’s payer mix and not about any market. The payer mix to weight by is yours to declare.
WHAT WOULD SETTLE IT Your own payer mix, declared.
- R-04
A per-provider payment prediction, or a ranking of providers
Provider rows are observations of contracted rates, and 30 to 60 percent of small-cell variation is sampling error before anything else is said.
- R-05
A clinical claim about any device or test
This corpus prices procedures and holds no evidence about whether a product works. A cited effect size for an intervention class is never evidence about a named product’s performance.
WHAT WOULD SETTLE IT A trial of the named product.
- R-06
What was in force after the world’s vintage
Rates refresh monthly, coverage articles change weekly, and upstream files are deleted at roughly 90 days. The vintage a claim relied on has to be named, and a claim carried across vintages must be rechecked, never inherited.
WHAT WOULD SETTLE IT A later vintage, read.
- R-07
Non-coverage from the absence of a rate row
Payers omit, fragment and misfile disclosures market-wide. One payer’s disclosure spans roughly 11 million separate files. The supportable sentence is that no rate was recorded in this month’s disclosure, not that the code is not covered.
- R-08
A Medicare bundling verdict, or any verdict for a pair with no edit row
The Medicare NCCI baseline sits behind an AMA CPT licence form and is not held here. The edits served are the Medicaid edition, which CMS publishes ungated. The two are not guaranteed to agree. A pair with no row is unknown, never permission.
WHAT WOULD SETTLE IT The Medicare NCCI PTP file, under licence.
- R-09
A saving for a named payer’s own book
The deferred-versus-avoided arithmetic runs over assumptions you declared. A payer’s realised saving depends on their population, contracts and utilisation, none of which this world holds.
WHAT WOULD SETTLE IT That payer’s own book, declared by them.
- R-10
A total that sums a deferred cost with an avoided one
A cost that arrives later is not a cost that never arrives. Any figure adding a timing shift to a prevented event reports a saving that does not exist. The two come back as separate totals and no combined one is served.
- R-11
Who may furnish or interpret a code, from the fee schedule
The PC/TC indicator and the status code say whether a code splits and whether Medicare prices it nationally. They do not say which specialty may furnish the professional component. That question is answered from coverage articles, and only where an article says so.
WHAT WOULD SETTLE IT A Local Coverage Article that names the requirement.
- R-12
How many people in a geography have a condition, or a prevalence converted between measurement classes
No source shipped observes below the national level, and administrative and epidemiological prevalence diverge in both directions. Every cohort figure names the class it came from, and this world holds no factor for converting between them.
- R-13
A causal effect from a comorbidity edge, or a combined risk across edges
Every edge served is observational and adjusted, and adjustment is not randomisation. The severity-stratified estimates share their comparator with the unstratified ones, so multiplying the two reports a hazard nobody measured.
WHAT WOULD SETTLE IT A randomised trial.
- R-14
A causal effect from a hypertension prognostic record
Nobody in those cohorts was randomised. A hazard ratio for a pressure predicting an outcome is not the effect of lowering that pressure.
WHAT WOULD SETTLE IT The randomised records, served by a separate tool.
- R-15
A figure combining the observational and randomised lists
A prognostic hazard ratio and a randomised risk ratio are different kinds of number against different comparators. No arithmetic over one of each is a quantity anybody measured. Ask twice and read them side by side.
- R-16
A readmissions penalty, an excess readmission ratio, or any 30-day readmission figure
No record held counts 30-day unplanned readmissions for an index condition. The nearest record, all-cause hospitalisation over 6 to 12 months in trial participants, has a different numerator, denominator and period.
WHAT WOULD SETTLE IT The Hospital Readmissions Reduction Program methodology and the hospital’s own claims.
- R-17
A HEDIS rate, a Star Rating, a quality bonus or a Medicaid capitation withhold
HEDIS specifications are NCQA’s and licensed. Star Ratings notes and the readmissions methodology are CMS’s. None of the three is held here, so this world reports what the literature published and never what any measure counts.
WHAT WOULD SETTLE IT The licensed measure specification.
- R-18
A cardiovascular risk or treatment effect for your own population
Every record names the people it was measured in. The cardiac rehabilitation trials recruited under 15 percent women, and the prognostic records are in people already treated for hypertension.
- R-19
A hospital’s charge compared with a payer’s rate
A charge is what a provider filed and a rate is what a payer published. They are different kinds of money, served through separate tools so no single call can ask for one of each and no arithmetic can cross them.
- R-20
A hospital’s filed payer name read as a payer
Those names are free text each hospital wrote for itself: 240 distinct strings, one company under several spellings, some naming a third-party administrator, some naming a government programme. Resolving one to a payer is an inference this world has not licensed.
- R-21
That a filer does not price an admission because the code is absent from their file
DRG groupers are revised and filers sit on different editions. A missing code may be one that edition does not define, and neither the schema version nor the vintage names the edition.
- R-22
A Cost of Care savings figure, from any money this world holds
A plan’s business case scores savings on paid amounts. No compartment here produces one. Payer files hold negotiated rates and hospital filings hold charges. A savings figure built from either and presented as Cost of Care savings is the artefact actuarial review exists to reject.
WHAT WOULD SETTLE IT Adjudicated claims.
- R-23
That a modelled saving is incremental, on a membership basis, or gross
The buyer’s standard requires all three, and each is a fact about a plan’s own run rate, membership and accounting. All three enter a submission as the plan’s declared inputs and never as anything this world verified.
- R-24
A question from a branch of the medical-cost lever tree this world does not sit on
This world sits on the reduce-unit-costs branch, contracted-pricing leaf only. A pharmacy question meets an absent corpus. An overpayment question meets an absent corpus and a licence wall. A demand question is utilisation, which is adjudicated claims, which a price says nothing about.
- R-25
What an avoided admission is worth to the provider who avoided it
The same avoided admission is revenue that never arrives under fee for service and cost never incurred under a risk contract. The sign is decided by the contract, and this world has read no contract.
WHAT WOULD SETTLE IT That provider’s own contract terms.
How a refusal arrives
A refusal comes back as an ordinary successful result carrying
kind: "refusal", a reason, and a cannot_be_concluded
naming the sentence the evidence will not support. Absences are typed too: a
code outside the vocabulary was never searched, a table this build never
read, a field the publisher withheld, and a cell somebody looked for and found
empty are four different facts, and the world says which one you have.
Read verbatim from the world's own hello_world on 6 September 2026.
When the world bumps, this page is rebuilt from it.