The national law firm Covington has a strong team on reimbursement for drugs and devices - here.
They now have a new book, Market Access, Pricing and Reimbursement of Drugs and Devices: Legal Principles and Practice, Desai et al. 2023. It's on sale at American Health Law Association (AHLA; around $200), here.
See also a Covington web page offering an excerpt and a discount code - here.