Impact of the loss of laboratory developed mass spectrometry testing at a major academic medical center

•VALID threatens the ability of laboratories to provide timely patient care.•VALID threatens the financial health of hospitals in a time of financial stress.•Loss of tests at our institution show VALID's potential impact.•Turnaround times for critical immunosuppressant drug levels were prolonged. Our laboratory historically performed immunosuppressant and definitive opioid testing in-house as laboratory developed (LDT) mass spectrometry-based tests. However, staffing constraints and supply chain challenges associated with the COVID-19 pandemic forced us to refer this testing to a national reference laboratory. The VALID Act could impose onerous requirements for laboratories to develop LDTs. To explore the potential effect of these additional regulatory hurdles, we used the loss of our own LDT tests to assess the impact on patient care and hospital budgets. Laboratory information systems data and historical data associated with test costs were used to calculate turnaround times and financial impact. Referral testing has extended the reporting of immunosuppressant results by an average of approximately one day and up to two days at the 95th percentile. We estimate that discontinuing in-house opioid testing has cost our health system over half a million dollars in the year since testing was discontinued. Barriers that discourage laboratories from developing in-house testing, particularly in the absence of FDA-cleared alternatives, can be expected to have a detrimental effect on patient care and hospital finances.