The IRS today in a press release announced that it has issued proposed model documents that can be used as trust or custodial agreements for Health Savings Accounts (HSAs). These documents "are being released in proposed form in order to give the public the opportunity to comment on the content before being issued in final form." The public comment period is 30 days.
The link to the model Health Savings Custodial Account is here [pdf] and the link to the model Health Savings Trust Account is here [pdf] .