The Health Insurance variables you mention should come very close to comprehensively measuring the full sample of uninsured persons. I recommend reading the discussion on the comparability of Health Insurance variables found in the variable description for VERIFY. Additionally, VERIFY will help you identify the small number of respondents with health insurance that was not included in the four variables you list.
Depending on your time frame of interest, you should consider using the Summary Health Insurance variables constructed by the State Health Access Data Assistance Center (SHADAC) at the University of Minnesota and available in IPUMS-CPS. These variables fix some of the comparability issues found in the CPS health insurance variables. You can find a schematic diagram of the summary health insurance variables at the bottom of this page, which lists the component variables used to create the summary health insurance coverage variable (HCOVANY).
Hope this helps.