Non-salary fellowships and US income taxes In general, are fellowships which are granted to individual researchers, but do not constitute salary and are not held in a personal bank account, considered taxable for US passport holders? 

For example, if a US national has a postdoctoral contract which gives them an income, and they are awarded with a supplementary fellowship for travel and research expenses, does the researcher need to declare only their salary when they file income taxes, or do they need to declare salary + the fellowship? 

I understand that fellowships can now be considered taxable under some conditions:


  Taxable 
  
  You must include in gross income:
  
  Amounts used for incidental expenses, such as room and board, travel,
  and optional equipment. Amounts received as payments for teaching,
  research, or other services required as a condition for receiving the
  scholarship or fellowship grant. However, you don't need to include in
  gross income any amounts you receive for services that are required by
  the National Health Service Corps Scholarship Program or the Armed
  Forces Health Professions Scholarship and Financial Assistance
  Program.


However, it is not clear how it would apply in this case.

I'm also confused as to the specific circumstances of a US national who is working outside of the US in this situation (postdoc salary and fellowship are both of non-American origin). I know that they must file their taxes in any case, but that their tax payment is usually 0 due to the Foreign Earned Income Exclusion. If this researcher's salary is ~$50k/yr and the fellowship is ~$50k/yr, this puts the researcher near the exclusion limit if the fellowship is also taxable.

It would seem that if the fellowship is awarded to somebody for purposes other than obtaining a degree, the fellowship is indeed taxable. However this seems like a very undue burden for a researcher, where getting fellowships and grant funding is considered vital for their success. Am I missing something?
Fellowship funds used for personal expenses including room and board, food, etc, are taxable, just like it says in the passage you quoted.

If social security taxes, medicare, etc, is not withheld, you don't need to pay those, since it is taxable income but not taxable wages. In that way, a fellowship is treated like any other academic scholarship that includes money for living expenses, rather than like an hourly/salaried position.

See also How much are taxes for a postdoc in the United States? though that question is not specific for fellowship-based income.

Fellowships awarded to individuals that include other expenses, like research expenses, are typically granted to the institution not to the individual, so those other expenses would not be part of your personal income even if it is an individual expenses. If they were paid to an individual, you would likely be able to deduct them as business expenses, but you would be best off working with an attorney or tax professional in that unusual situation.

If you are talking about receiving a foreign $50k fellowship in addition to a foreign $50k salary abroad, then yes indeed you are approaching limits for exclusion of foreign income but it is unlikely you will be taxed twice on the same income due to foreign tax credits for US taxes, but that is really now an issue of tax law for expats and not really related to academia specifically; that situation seems like it would be quite unusual in academia for a post doc, and although it may place a burden on a researcher, an income of $100k+ would place you in a fairly high percentile of individuals where the US government expects that there is a burden on your income to pay for the costs of society - this is true in many other countries as well.