If a president is impeached and removed from power, do they lose all benefits usually afforded to presidents when they leave office? quotes the Former Presidents Act as defining a former President as
a person ... whose service in such office shall have terminated other than by removal pursuant to section 4 of article II of the Constitution of the United States of America; and
There are a number of benefits that former Presidents lose if they're removed from office by impeachment (e.g. a pension and office staff, but not Secret Service protection). Trump was removed from office due to losing the election, not as a result of impeachment. So does that mean he'll continue to receive those the benefits afforded by the Act?
If he does, I suppose Congress could (if it wants to) amend the Act (to change the definition) or pass a new law to specifically deny Trump these benefits. This is likely to be moot, as getting 17 GOP Senators to break ranks and vote to convict Trump will be difficult.