Behavioral Health Compliance Startup Brellium Raises $23 Million

Brellium, a New York company that sells billing-compliance software to behavioral health providers, has raised $23 million to move the same auditing tools into pain management and primary care, the company said, extending a category of artificial intelligence that reads clinical notes rather than claims.

Left Lane Capital and First Round Capital led the round, with Digital Health Venture Partners participating, Behavioral Health Business reported. Both lead investors had backed the company's previous raise, a $16.7 million Series A announced in April 2025.

What the money buys

The funding is earmarked for new segments of healthcare and additional parts of the revenue cycle, according to the company. Alongside the round, Brellium introduced CortexLM, an auditing system it says reads every patient note, trains on a given organization's own requirements and flags problems in documentation before a claim is submitted for payment.

Brellium's customer base covers roughly 200 provider groups across all 50 states, and it counts behavioral health organizations alongside national post-acute care providers including Gentiva and Maxim Healthcare. The company's own site claims its software is used by more than 250,000 providers, a figure it does not break down further. Its expansion targets cardiology, pain management and primary care — the last two being areas where documentation review has become a recurring point of friction.

Why notes, not claims, are the product

Most compliance software in healthcare works backward from what was billed: it looks at claims and payment data and identifies patterns that suggest overpayment, then leaves the provider to reconstruct the clinical record that justified them. Brellium's pitch inverts that sequence. If a note cannot support the code it is about to be billed under, the problem surfaces while the note can still be fixed, which is cheaper than defending a demand letter two years later.

For mental health and substance use treatment providers, the economics of that gap are unusually sharp. Sessions are documented in narrative prose, lengths of service vary by a few minutes in ways that change the billable code, and group sessions require specific attestations. Small documentation failures scale into large recoupments precisely because the services are high-volume and low-margin.

The audit environment behind the pitch

The federal government has named autism therapy, a core market for Brellium, as high risk for fraud, waste and abuse, and that designation has consequences that reach beyond any single provider type. Behavioral health organizations that bill Medicaid and Medicare face post-payment review, and the failure modes are not always dramatic: documentation that cannot support a service level, staff who never signed a note, sessions billed after the treatment had in fact been shorted.

The consequences are visible in enforcement. Montana prosecutors charged a Great Falls addiction counselor with felony Medicaid fraud this month over claims for sessions that patients did not attend, the second such case against a city treatment provider this year. In that case, a former client's explanation of benefits — not an auditor's algorithm — started the investigation.

Investors have kept funding behavioral health software through 2026 despite a soft market elsewhere. The autism therapy software company Hi Rasmus announced a $50 million round last month, and the behavioral health data platform Onos Health raised a $17 million Series A in August.

What the round does not fix

Compliance tooling does not change what a provider is paid, and the shortage of clinicians is not a documentation problem. Automated note review can also go wrong in the other direction: software tuned to catch undercoding will surface revenue a practice is entitled to bill, which is the more welcome half of the pitch, but it can equally encourage providers to defend every note as adequately documented when the underlying service was thin.

Brellium's own description puts the object of its auditing in plain terms — catching risk before it becomes a clawback. In a system where the audit usually arrives years later, that is a bet that providers will pay for certainty about their own paperwork, and it is a bet being made across a treatment field that has spent the past decade learning how expensive vague documentation can be.