State PBM Reform Laws in 2026: What Changed for Pharmacy Audits

Two 2025 and 2026 state laws are rewriting what a PBM audit can demand from a pharmacy before a single dollar of recoupment changes hands. Oklahoma's SB 993 bars PBM auditors from using extrapolation to calculate recoupments and caps the number of prescription claims a PBM can audit each year. Delaware's SB 271 limits how often a PBM can audit the same pharmacy and shifts the cost of the audit onto the PBM. Which state issued the audit notice now changes what the PBM is allowed to do before it can issue a final recoupment demand.

Oklahoma Ends Extrapolation and Caps the Audit's Reach

Oklahoma's SB 993 became law on May 22, 2025, amending the state's Pharmacy Audit Integrity Act at 59 O.S. Section 356.2 and Section 356.4. Section 356.4(B) bars the entity conducting an audit from using the accounting practice of extrapolation in calculating recoupments or penalties, closing off a PBM's ability to project a handful of flagged claims across an entire reimbursement period. Section 356.2(D) caps the PBM's reach directly: it may not audit more than 50 prescription claims, identified by prescription number and date of fill, from a single pharmacy in a calendar year, inclusive of every audit the PBM or its agent runs that year. Section 356.2 also protects clerical and recordkeeping errors, such as a miscalculated day supply or an incorrectly billed prescription date, from recoupment unless the PBM can show intent to commit fraud, and lets the pharmacy correct those errors electronically instead of paying them back. The extrapolation ban gives a pharmacy a concrete argument against an audit letter that projects a sample finding across years of claims; our analysis of challenging extrapolation in a PBM audit covers how that argument is built.

Delaware Shrinks the Audit Calendar and Shifts the Cost

Delaware's SB 271, signed September 8, 2026, rewrites the audit rules at Title 18, Section 3304A of the Delaware Code. Section 3304A(a)(6) bars a PBM from initiating an audit of the same pharmacy more than once every 12 months. Section 3304A(b)(9) puts the cost of the audit on the PBM conducting it, not the pharmacy being audited, and Section 3304A(a)(1) still requires 14 days' notice before an on-site audit begins. The same bill separately widens the pharmacy's window to challenge a maximum-allowable-cost reimbursement from 10 calendar days to 40 calendar days under Section 3324A(a)(2), a reimbursement protection rather than an audit-specific one, and lets a pharmacy that loses that dispute escalate it to the Delaware Department of Insurance under Section 3324A(c)(2).

What Pharmacies Should Expect From Their Own State

Pharmacy-audit protections change from session to session: Oklahoma's extrapolation ban and claim cap, and Delaware's 12-month audit interval and cost-shift, are each 2025 and 2026 changes. The protections differ by state and by the entity running the audit, and a PBM audit, a Medicaid managed care audit, and a Medicare Part D sponsor audit can draw on different statutes inside the same state. The same recoupment finding that triggers an audit appeal can also become the PBM's stated basis for network termination if the pharmacy misses the statute's deadline, which is why the deadline itself, not just the dollar amount, is worth checking against the current law in the state where the audit was issued. The underlying audit mechanics these reforms narrow are the same mechanics behind how PBMs flag claims for closer review; our coverage of compound claim audits and controlled substance claims in a PBM audit walks through how those reviews typically unfold.

Oklahoma's ban on extrapolation and Delaware's 12-month audit interval do not take away a PBM's recoupment authority. They narrow what that authority can reach and how often it can be used.

Why Early Legal Counsel Is Critical

It is critical that pharmacies promptly retain experienced healthcare defense counsel upon receiving a PBM audit notice, a preliminary audit findings report, or a recoupment demand, regardless of which state's audit statute applies. Early legal intervention can confirm which protections actually apply to the audit in hand, such as an extrapolation ban, a clerical-error carve-out, or an extended appeal window, ensure the pharmacy's response preserves rather than waives those protections, and allow counsel to communicate with the auditor on the pharmacy's behalf. Delaying legal representation can significantly affect the outcome of a matter and expose the pharmacy to unnecessary risk.

How Health Law Alliance Can Help

Health Law Alliance's PBM audit defense attorneys track state pharmacy-audit statute changes as they are enacted and apply the specific protection that governs each audit: Oklahoma's extrapolation ban, Delaware's 12-month audit interval, or another state's clerical-error carve-out. Health Law Alliance's attorneys have overseen 2,000+ audits and handled 5,000+ matters, with 25+ years of experience. If your pharmacy has received a PBM audit notice or a recoupment demand, contact Health Law Alliance's PBM audit defense attorneys for a free, confidential consultation.