One of my 401k accounts is with J Hancock and is administered through the HR person at my employer.  Can the Plan administrator view my balance?

Most likely yes.

yes they can. are you worried they can see it?

Not worried, let's just say "concerned" with who or how that information would be used or get around.  I have done well with my other 401k account and had thought about moving it over.  However, I don't have a high level of trust internally from other things I have seen and heard.  JH customer service only has one answer for everything.  "Call your Plan Administrator" which is not very inspiring or trustworthy either.

I appreciate the replies guys.

No problem, as a side note there are a few reasons why rolling over an IRA into a 401k makes sense.

Move to a small town.  About 70% of the people will think they know everything about your private business.  90% of that 70% will not be anywhere near close to right.

It would be hilarious if it weren't so pathetic.

don't roll an "old" 401k account over into your new company's 401k custodian.
doing so is very limiting, and handcuffs you to the new company's 401k plan.

roll an "old" 401k account into an IRA at the custodian of your choosing (e.g. Fidelity, Vanguard, T.Rowe Price, etc).
this type of 401k to IRA rollover gives you many, many more options, and is a taxless exercise.

any IRA custodian can do this via a "pull", with minimal involvement from your end aside from setting up the account.

you can also request a full distribution of your current 401k via a live check, and then use that to open the IRA.
treat that live check like plutonium -- under IRS rules you have 60 days to roll that money into another qualified plan otherwise it will turn into a "taxable event".
in that case you are well and truly screwed, especially so if you are under 65.  so don't do that.  

ar-jedi

We just switched to john hancock after edward jones got sued or whatnot.

I was literally standing over my office managers shoulder a second ago looking at the account, so yes, yes they can.

Luckily my office manager is good and her and I are the only ones out of 35 that use the 401k so it's not a big deal. She handles all questions and loan issues on it.

To add on to your post, some 401k companies will only accept their paperwork, since there may be both a plan admin and a TPA that needs to sign off.

I also think I missed somthing about being under 65.