The instructions for preparers of 1099-R are 14 pages of gibberish. I'm not sure the following, on Page 6, is the rule they follow. It appears to make a distinction between "rollover" and "transfer." My experience, though, is that many trustees or plan administrators try to convince account holders to sign up for electronic delivery of everything, including tax documents. If you think there should be a 1099, ask if the client gets everything else by mail. (This is more of a problem with 1099-SA forms, than 1099.R.)
Transfers
Generally, do not report a transfer between trustees or
issuers that involves no payment or distribution of funds to
the participant, including a trustee-to-trustee transfer from
one IRA to another IRA, valid transfers from one section
403(b) plan in accordance with paragraphs 1 through 3 of
Regulations section 1.403(b)-10(b), or for the purchase of
permissive service credit under section 403(b)(13) or section
457(e)(17) in accordance with paragraph 4 of Regulations
section 1.403(b)-10(b) and Regulations section 1.457-10(b)
(8). However, you must report:
• Recharacterized IRA contributions;
• Roth IRA conversions;
• Direct rollovers from qualified plans, section 403(b) plans,
or governmental section 457(b) plans, including any direct
rollovers from such plans that are IRRs or are qualified
rollover contributions described in section 408A(e); and
• Direct payments from IRAs to accepting employer plans.
https://www.irs.gov/pub/irs-pdf/i1099r.pdf
