PAYERBENCH ENVIRONMENT · TRAINING & EVALUATION METRICS

PayerBench training results.

De-identified outpatient claims, nine evidence tools, and a deterministic remittance-based verifier. Metrics reflect the current evidence, including measurements still to be established.

Yash Joshi & Roshan Patel · October 22, 2026 · Prediction-integrity scorer revision

59.7%GPT 6.1 baseline · CI [56.8, 62.7]
+0.8 ppRL vs SFT · CI [−1.2, 2.8]
+7.5 ppSFT + RL vs base · CI [4.7, 10.1]
Frontier model baselinemeasured59.7% pass@1

750 claims; equal paid, partial, and denied weight; 95 payers.

Held-out capability gain after RLmeasured+0.8 pp overall; +7.6 pp on denied claims

Seed 2 − SFT. Overall CI [−1.2, 2.8]; denied CI [4.4, 11.2]. Seed 1 overall: −4.5 pp.

Unseen task-family gainunmeasuredNot measured

All six controlled families were represented in training; no held-out-family experiment.

Production-derived holdout gainmeasured+0.8 pp incremental RL; +7.5 pp for SFT + RL

Same holdout as above. SFT + RL vs base CI [4.7, 10.1]; no independent replication.

Sim2Real transfer efficiencynot applicableNot applicable

Production-derived training and evaluation; no separate simulator-to-production stage.

Human / reward agreementunmeasuredNot measured

No independent expert agreement study. Labels are observed payer responses.

Reward false-positive rateunmeasuredNot established

No independently adjudicated reward-correctness set.

Reward exploit rate after red-teamingscoped0 / 2,247 fixed attacks rewarded (0%)

Three fixed mutation classes × 749 accepted references; no open-ended adversarial search.

Effective environment scalescoped18,445 training task IDs / 6 controlled families

12,618 observed + 5,827 constructed tasks. Distinct IDs; semantic redundancy unaudited.

Saturation pointscopedNot established; 7,752 rollouts / seed observed

Ten updates per seed; dev peaks at step 15, then falls at 20. No saturation study.

Throughputscoped2.83 rollout attempts/sec

8B / H100: 7,752 attempts in 2,738 rollout seconds; 0.42/sec with updates. Excludes validation/setup.

Environment reliabilityscoped99.6% valid evaluated completions (1,550 / 1,556)

Final seed 2 results after retries; prediction + process + integrity pass. Not uptime.

Cost per 1M valid episodesscopedNot measured; ~$93 total experiment spend

Reported total: this version’s SFT, RL, control, and evaluation (29 GPU-hours). Unit cost unmeasured.

Learning efficiency per $10K trainingscopedNot established; +0.8 pp at the selected RL checkpoint

Seed 2: five updates, 3,876 rollouts, 2.72 GPU-hours excluding SFT/validation/setup. No dollar extrapolation.

Synthetic substitution gapunmeasuredNot measured

No matched training comparison against a strongest cheap synthetic replica.

Scope: Pass@1 requires the full claim, line, and reason-code prediction. Observed-claim test: 750 claims, 250 per outcome, 95 payers; 558 allergy/immunology, 165 dermatology, 27 orthopedics. The full corpus is 24,302 claims, 486 payers, five specialties.

Audit: Three fixed mutation classes × 749 accepted canonical references. One additional reference has a source-label inconsistency. Zero accepted mutations does not establish zero general exploit risk. Throughput and completion are reference-policy measurements, not service guarantees.

Evidence: Saved model predictions rescored without new inference; saved trainer timing logs; paper-reported compute estimate; targeted verifier audit. Measured = direct result; scoped = bounded evidence; unmeasured = no supporting experiment; not applicable = outside the evaluation design.