Start with high-confidence health insurance books, then narrow by subgenre or adjacent topics.
The Economics of Health and Health Care
Sherman Folland, Allen C. Goodman
Never Pay the First Bill
Marshall Allen
We've Got You Covered
Liran Einav, Amy Finkelstein
Why Nobody Believes the Numbers
Al Lewis
Medicare for Dummies
Patricia Barry
Understanding Health Insurance
Michelle Green
The Transformation of American Health Insurance
Troyen A. Brennan
Health Insurance, Third Edition
Michael A. Morrisey
Get What's Yours for Medicare - Revised and Updated
Philip Moeller
The Company That Solved Health Care
John Torinus