In diagnostics and specialty pharma, accounts receivable growing materially faster than revenue (>2x ratio, sustained 2+ quarters) signals collection quality risk. The mechanism: rapid commercial expansion into new payer networks and formularies creates a lag between service delivery and reimbursement receipt, inflating A/R. If the payer mix is expanding faster than the company's reimbursement infrastructure can clear, or if in-network coverage is being recognised as revenue before contracts are executed, A/R can compound in ways that eventually require reserves or write-downs.
This flag is distinct from the normal A/R build that accompanies revenue acceleration. The threshold is >2x A/R growth vs. revenue growth, sustained across multiple reporting periods.
Add A/R growth relative to revenue growth as a standard check in all diagnostics and specialty pharma analyses. When the ratio exceeds 2x for 2+ quarters: (1) probe payer coverage timeline vs. billing start date, (2) check if the in-network contract effective date creates a gap, (3) evaluate whether launch SG&A is pulling revenue forward in a way that cannot be collected at the expected rate. Flag as yellow, not red — it can reflect legitimate ramp dynamics, but it escalates to red if DSO is also expanding.