MAIAC uses surface reflectance as a tool to produce its atmospheric results.

All the MODIS data is available here: https://ladsweb.modaps.eosdis.nasa.gov/missions-and-measurements/science-domain/maiac

The MAIAC Users Guide (https://ladsweb.modaps.eosdis.nasa.gov/missions-and-measurements/modis/MCD19_MAIAC_UG_06-2018.pdf) does not mention NDVI or EVI. My understanding was that MAIAC uses the surface reflectance data from MODIS directly, no need or point in going through an NDVI or EVI process first.

The MODIS NDVI data is found here: https://neo.sci.gsfc.nasa.gov/view.php?datasetId=MOD_NDVI_M

Perhaps this page will be of use: https://modis-land.gsfc.nasa.gov/vi.html

Perhaps I am just completely missing the point of your question.

Thanks Matthew, but the data you linked is only surface reflectance. I found the EVI and NDVI dataset here: https://portal.nccs.nasa.gov/datashare/maiac/DataRelease/. The subdomain had changed names from what was cited in previous publications. The dataset provided in 8-day format at 0.05 CMG spatial resolution and is in the Global-VI-8day-0.05degree/ folder.

It sounds like you've found what you wanted, but I'm pretty sure the third link is to the processed MODIS NDVI data, although perhaps not in the format you want. That link does direct one to another source for other data formats if one chooses the CSV format.