TPG question--applies to HSA, too?

As I understand it, if an Employer choses to utilize the Top Paid Group (TPG) for it's benefit plans, it must be used on all benefit plans, retirement and non-retirement plans.

So, this would include 401(k) and an HSA, right?  if an employer wants to use TPG for HSA, they have to use it for the 401(k) right?

But what happens if you have conflicting choices?  The HSA says TPG and the 401(k) plan says standard?

Notice 97-45 defines the word "plans" to include any employee benefit arrangement that references 414(q) for its internal nondiscrimination testing.  All plans of the employer must make the election to be effective; if they don't all make the election, it isn't available to any of them.

The plan(s) may be amended mid-year as long as it doesn't adversely affect a participant's accrued benefit (anti-cutback rule).

Even presuming consistency rules for all an employer’s employee-benefit plans (of those that seek to meet a tax law condition that refers to Internal Revenue Code of 1986 § 414(q)):

The Treasury department’s temporary rule (adopted February 19, 1988, and last amended June 27, 1994) interprets § 414(q) as it was in effect for 1996 and earlier years.

Under that rule, § 414(q)’s definition for a highly-compensated employee applies if another Internal Revenue Code section refers to § 414(q).

26 C.F.R. § 1.414(q)-1T https://www.ecfr.gov/current/title-26/chapter-I/subchapter-A/part-1/subject-group-ECFR686e4ad80b3ad70/section-1.414(q)-1T

About health, other welfare, and fringe-benefit plans, that § 414(q) temporary rule lists sections 89, 106, 117(d), 125, 129, 132, 274, 423(b), 501(c)(17)-(18), and 505.

Section 223—Health Savings Accounts states no reference to § 414(q).

Does some coverage or nondiscrimination rule apply intermediately or indirectly?

Thanks @Peter Gulia.  That's a great link!

Yeah, I saw that as well, and chuckled at the Section 89 reference, that's how old this was.